MULTIFUNCTION INTERFACE DEVICE FOR USE, INTER ALIA IN LABORATORY PROCEDURES
Field of the invention
The present invention relates to a multifunction interface device for laboratory procedures. More particularly, the present invention relates to a multifunction interface device for data acquisition and control of real world devices in a laboratory environment. Background of the invention
Computers and computer related technology are increasingly being used for varied applications in the field of business, manufacturing and even in academic, clinical and research institutions. In today's world, computerization has become necessary for businesses to remain competitive. Computer systems are increasingly being used to automate processes, manage large amounts of data, and provide fast, flexible communications. Computerized business functions include billing, order-taking, scheduling, inventory control, record keeping, and the like. Computerization for businesses can be accomplished by using standard business application systems that run standard business applications software packages.
Several software packages are available for business applications to handle a wide range of business functions, including those discussed above. For example, the SAP R/2 System available from SAP America, Inc., is a business applications software package designed to run on an IBM or compatible mainframe in a customer interface control system (CICS) or information management system (IMS) environment. For example, SAP may use CICS to interface with terminals, printers, databases, or external communications facilities such as IBM's Virtual Telecommunications Access Method (VTAM). SAP is a modularized table driven business applications software package that executes transactions to perform specified business functions such as order processing, inventory control, and invoice validation; financial accounting, planning, and related managerial control; production planning and control; and project accounting, planning, and control. The modules that perform these functions are all fully integrated with one another.

Most manufacturing operations are also now computer controlled. For example, it is now common in the art for computer or computer systems to provide real-time process control for component manufacturing and process manufacturing such as in the chemical manufacturing industry through the use of real-time process control systems.
It has increasingly become common for laboratory procedures in academic and research institutions to also be computer controlled in accordance with preset parameters. The advantage of computerization in the laboratory environment whether clinical, research industry or academic, is that the margin for error due to human intervention is reduced substantially thereby ensuring a greater accuracy of results. Such computer systems are generally known in the art as Laboratory Information Management Systems (LIMS). In the laboratory environment, computers are typically employed to manage data regarding product samples being tested. Computers are also used conventionally to automate the testing and/or sampling processes. Commercially available LIMS system include FISONS LIMS from FISONS Instruments, Inc., SQL*LIMS from Perkin-Elmer and EASYLIMS from Beckman.
Conventionally, integrating computerized laboratory information management systems often requires a human interface. As a result, the level of automation in laboratory procedures, whether clinical, research industry or academic, is low. Traditionally, human operators are responsible for data collection and collation from the laboratory information management systems.
It is also known to implement customized computerized interface between different procedures in laboratory systems. However, these customized solutions are generally experiment specific. As a result, such a solution cannot be transported to other experiments without major modifications. Additionally, these solutions are costly to maintain over time because of inherent difficulties in accommodating change.
In many laboratory operations, multiple real-time process control systems are implemented to control different procedures. A significant problem of such multiple

real-time process control systems is that all the interfaces to respective computers are not necessarily uniform. In such a situation, the process control supervising computer needs to be provided to serve as a single constant interface to the different multiple, real-time process control systems having different interface characteristics. The process control supervising system then allows operators to provide data to specific real-time process control systems and retrieve data about the process from those real-time process control systems. As can be seen the disadvantage of such a system lies in the number of computing systems required in cases where a multiplicity of measurements or data readings are to be taken.
In typical laboratory systems, there are diverse situations calling for different solutions. These situations generally include characterizing output as relating to either a period of time during which manufacturing occurs or to quantity of material produced. In other words, output can be characterized with either time-based units or physical quantity units.
For example, modern clinical laboratory procedures include biological and chemical analysis of specimen substances that require extensive fluid manipulations. Generally, the routine applications used for analysis are bioassays, immunoassays, viral assays, mitogen assays, serology, protein assays, lymphokine assays, and sample aliquoting. Experimental biological and clinical research include the use of photometric analysis of chemical reactions after the reactions have reached equilibrium or a fixed end point. Certain enzyme assays require a two-point or multi-point analysis embodying kinetic assays.
Standard fluid transfer and manipulative techniques include pipetting, diluting, dispensing, aspirating and plate washing. Conventional assays are normally performed by rapid manipulation of manual pipettes or conducting assays that are automated piecemeal. Common assays such as ELISA (enzyme linked immunoassay), viral, protein, and other biochemical studies and experimentation require liquid handling such as sample preparation, serial dilution, reagent addition and sample transfer to yield results. Bioassays and chemical experimentation, which require making use of such liquid handling techniques, when performed manually,

are subject to potential inaccuracies. For example, it is difficult for a laboratory technician to ensure accurate dispensation of the exact amount of liquid in each of 96 wells on a plurality of microtiter plates. The repetitious nature of liquid handling for experimentation inherently leads to mistakes that are not always detectable.
Traditionally, experimental, clinical, and other laboratory procedures require tedious step-up-step sample and control preparation which are then sequenced through a series of operations depending on the raw measurements, their analysis, and the nature of physical, chemical or biological investigation.
The teaching of science and engineering requires that a student be exposed to lectures, to read textbooks, to perform experiments in laboratories, to solve problems, and finally to be tested as to the knowledge he has acquired. This process is generally disjointed and may result in a typical student being unable to achieve a sense of integration in the subject matter.
A traditional laboratory course in science disciplines consists of a list of experiments intending to familiarize students with experimental techniques and measuring instruments as they record phenomena or measure physical quantities of interest. Rarely do these provide a link with the real world or concretize learning of abstract theoretical principles. Each experimental set up appears as something new to the student and the student is unable to see that very few principles and generic procedures are used in any measurement system and that a great deal is common amongst seemingly disparate measurements. Thus it is doubtful if the experiments teach the "craft of the experimenter". This is amply illustrated by the helplessness that is displayed at times by students when asked to design an experimental setup to observe or measure something not encountered before and to fit things in the overall theoretical perspective of the disciplinary domain.
Very often, laboratory work also tends to generate ennui. Students are unable to grasp the functioning of the multiplicity of measuring instruments and different control systems employed in the measurement process. Mismatched pieces of equipment and procedures lead to rapidly propagating measurement errors. Students find laboratory work as time consuming, nianually repetitive, tedious and

inherently prone to lack of precision as well as measurement inaccuracies. Traditional measurement systems do not produce easily repeatable or reliable results because of difficulties in achieving sufficiently accurate control conditions. Sometimes, laboratory experiments also tend to be dangerous unless closely monitored and controlled. Such a laboratory environment does not induce a student to respond to questions that arise in his mind or pursue an in-depth and scientifically rigorous investigation of the physical system.
Science classrooms, in general, fail to make use of computers as an enabling tool for enhancing learning of the subject. The undergraduate science laboratory courses fall short on teaching how the twin advances in microelectronics and microprocessors have revolutionized the concept of instrumentation and measurement. Students who are not familiar with automated data-acquisition systems and computer interfacing fail to understand how experiments are designed and executed in the workplace in the contemporary technology driven work place.
In general, scientific inquiry proceeds by proposing a hypothesis and establishing its validity through carefully crafted experiments. The objective of a typical experiment is to observe natural phenomena as these occur and discover empirically the relationship that exists between various system parameters evoking the well-established process of observation, analysis and data modeling. Based on the success of initial hypothesis, the process is gradually refined in several iterative cycles to establish a complete theoretical understanding of the phenomenon or the physical system. Central to this quest for theoretical understanding is the efficacy and reliability of the measurement process.
The starting point for any laboratory experiment is an experimental configuration of equipment, apparatus, devices, materials, and supplies. The operation of the experimental configuration is typically characterized by the relationships that exist among a plurality of experimental parameters. The nature of the relationships may be expressed by an equation or tables of values. The objective of a typical experiment is to measure one of the experimental parameters and then to determine the value of one or more other experimental parameters using the

characterizing equation or tables of values, the measured value, and the known values of the remaining experimental parameters.
Significant problems involved in laboratory procedures in academic institutions are that the equipment is not always especially designed for a teaching laboratory; is often expensive and is not easily available off the shelf. Inasmuch as there is little research and development work in the area of tertiary education, there are few instances wherein equipment for setting up novel and comprehensive laboratory systems has been designed by academics, themselves. As a result, dependence on vendors who work in isolation from academia and its special needs is perpetuated. What is available off the shelf at best caters to traditional demands. The non-availability of equipment specially designed to promote rigorous and meaningful learning of science poses a major impediment in ushering in radical changes in the learning environment or creating meaningful teaching-learning experiences. The applicants are unaware of any integrated multifunction computer interface capable of performing the role of a versatile laboratory instrument and enabling multi-faceted user interactions with the laboratory procedures. Such an interface would be of tremendous utility in any laboratory system, whether clinical, research, industry or academic. In the clinical environment or in the research environment, such a system would ensure accuracy of results. In the academic environment, enabling multi-faceted user interaction and the provision of accuracy of results ensures a better teaching environment. Prior art
US Patent 5813865 discloses an apparatus for teaching science and engineering as an interactive multimedia computer system which is used to simulate the performance of scientific experiments on the computer screen. An experiment is a method for determining the value of one experimental parameter by measuring the value of another using an experimental configuration of devices and apparatus. The interactions of the devices and apparatus in the experimental configuration are governed by a relationship among the experimental parameters that define the configuration. The user of the teaching apparatus assembles a pictorial

representation of the experimental configuration on the computer screen and interacts with the pictured experimental configuration to simulate the performance of an experiment. The pictured experimental configuration is governed by the same relationship among experimental parameters as the real configuration and thus, the results of the simulated experiment match the results of the experiment performed in the laboratory. Still images and short motion pictures relating to the subject matter of the experiment can be accessed by the user as an aid to his understanding of the subject matter.
This apparatus of this reference comprises a means for displaying imagery; a means for causing a plurality of objects to be pictured on the display means, the objects being apparatus, equipment, devices, materials, and supplies used in science and engineering; a means by which the user can assemble a plurality of the objects pictured on the display means into an operating pictorial representation of an operating experimental configuration, the experimental configuration being characterized by a relationship among a plurality of experimental parameters; means by which the user can simulate the performance of an experiment using the pictorial representation of the experimental configuration, an experiment being a method of measuring one of the plurality of experimental parameters by means of the experimental configuration, the operation of the pictorial representation of the experimental configuration being governed by the same relationship among the experimental parameters that characterizes the operation of the experimental configuration.
However, the apparatus of this patent is limited in use and very function specific. As such, the apparatus of this patent cannot be used for multiple functions and is therefore of limited utility in a general academic laboratory environment. Another disadvantage of this apparatus is that the equipment is not robust and therefore requires regular maintenance and replacement.
US Patent 6261103 discloses an interactive computer system for teaching laboratory-based sciences. According to one embodiment, the system includes a data acquisition module, an internot-based coursework database, and internet-based

interactive software tools. Using the interactive software tools, an instructor can select academic course materials and related laboratory experiments from the coursework database. The instructor can create an Internet web page, which provides students with an interactive visual interface with the selected course materials and laboratories, along with various analysis tools. The data acquisition module is located at the site of an experimentation laboratory, and interfaces with laboratory equipment to capture data from selected experiments. Experimental data is transmitted in real-time to an internet-based storage location.
The disadvantage of this reference is that the entire computer system is web-based and cannot function in a real world environment. Also, the system does not provide for multiple functions being done at one time.
U.S. Pat. Nos. 4488241 and 4510684 disclose a robot system with interchangeable hands and a module system; these patents are directed at a robot system for manipulating a series of discrete devices used in the field of analytical chemistry. These patents teach the use of a robotic arm to open, touch and manipulate discrete laboratory devices in an emulation of manual methods. These patents teach the use of a robot system to control these conventional laboratory instruments by their automatic manipulation; the techniques of the laboratory remain discrete and are not integrated into an intelligent and coordinated system. Objects of the invention
Accordingly it is an object of the invention to provide a multifunction interface device for laboratories that is capable of application both for teaching the rudiments"of interfacing in a student laboratory as also teacher training programs.
It is another object of the invention to provide a multifunction interface device for use in laboratories which performs the role of a versatile laboratory instrument and enables easily repeatable, reliable and accurate results.
It is another object of the invention to provide a multifunction interface device that can be used to perform experiments that involve time scales ranging from the very fast, such as few microseconds, to the very slow, such as several days.

It is a further object of the invention to provide a multifunction interface device that replaces in part or wholly complex physical measurement instruments.
It is another object of the invention to provide a modular interfacing package to develop technology enriched curriculum materials and resources for teaching of science primarily at the tertiary level with possible adoption at -both, the school level and the advanced research laboratories.
It is another object of the invention to provide a multifunction interface device for use in laboratories that is of use in both, traditional laboratory settings and more challenging project-based learning environments. Summary of the invention
The present invention provides a means for a user to assemble an experimental configuration using suggested hardware building blocks and carry out physically an experimental investigation in real-time under microcomputer control with the results of measurement being displayed numerically as well as pictorially through graphic and other iconic representations in real time.. The computer system also indicates in real-time the physical status of the observed system or underpinning phenomena as reflected by the measurement process at any instance evoking select representational formats.
The multifunction interface device of the invention is a simple but extremely powerful computer controlled interface for data-acquisition and control of real world devices. Used in conjunction with appropriate software, the interface of the invention is capable of converting the microcomputer into a versatile laboratory instrument.^ can perform the function, inter alia of a measuring instrument for output from a wide range of sensors and operate variously as a digital voltmeter, storage oscilloscope and x-y recorder. Further, it can act as signal generator, frequency analyzer, network analyzer, test instrument, logic probe, digital timer, event counter, switch control unit, device driver and controller. The functions listed herein are illustrative and by no means exhaustive.
Accordingly the present invention relates to a multifunction interface device comprising one or more signal generation means responsive to a sensor means

provided on an experiment set up in order to generate signals indicating a specific result required or obtained therefrom in machine readable form, said one or more signal generation means coupled to one or more signal transmission means, said transmission means transmitting said signals to a microcomputer through a captive port on said microcomputer.
In one embodiment of the invention, the signal generation means comprises an analog or digital signal generation means.
In another embodiment of the invention, the signal transmission means comprises of an analog to digital converter, a digital to analog converter, a plurality of digital input/ output channels or any of the above.
In another embodiment of the invention, the analog to digital converter converts said analog signals into digital signals readable by a microcomputer, and the interface is provided with digital input signal means connected to said analog to digital converter to transmit said digital signals to said microcomputer through a responsive parallel port provided on said microcomputer, digital output signal means provided to receive instructions from said computer and forward it to the experiment set up, said digital output signal means forwarding said instructions by means of a digital to analog converter.
In another embodiment of the invention, each of said analog to digital converter and digital to analog converters is provided with a captive signal conditioning circuit.
In another embodiment of the invention, the signal conditioning circuit is selected frcTm a buffer circuit, off balance bridge, gain amplifier, difference amplifier, instrumentation amplifier, voltage level shifter, current to voltage converter, multiplexer, filter, rectifier, differentiator, integrator and multiplier, and the like.
In another embodiment of the invention, the sensor means comprise of a conventional photosensor, ultrasonic transmitter/receiver, photogates, light emitting diodes, motion detector, photovoltaic cell,and the like.
In another embodiment of the invention, the digital input means comprises of a digital input/output bus comprioing cf at least one input/output channel.

In another embodiment of the invention, the interface is provided with a gate circuit operatively associated with any or all of said analog to digital converter, digital to analog converter, input output lines in order to transmit a user-determined set of instructions to the physical system.
In another embodiment of the invention, the multifunction interface device comprises of a digital to analog converter; an analog to digital converter; and a corresponding set of digital input and output lines, a plurality of analog input channels connectable and responsive to a plurality of sensory devices in order to measure and read input sensor data; at least one analog output channel responsive to the said plurality of analog input channels, and two or more digital input/ output channels, said analog output channels being operatively associated with a analog to digital converter to convert the analog output data into a digital data stream, said digital stream being fed into a microcomputer by means of a digital input/output bus, said analog to digital converter being provided with a multiplexer and a microprocessor compatible logic circuit.
In another embodiment of the invention, the multifunction interface device is capable of parsing a given algebraic function and generating a corresponding analog signal.
In another embodiment of the invention, the multifunction interface device is capable of parsing a function expressed as a table of numeric values and generating a corresponding analog signal.In another embodiment of the invention, the multifunction interface device is capable of multiplexing and measuring up to eight different analog signals each at two channels of the on-board analog-to-digital converter, providing measurements from an array of sixteen sensors.
In another embodiment of the invention, the multifunction interface device is •provided with means for changing the values of the experimental parameters each time an experiment is performed.
In another embodiment of the invention, the multifunction interface device is provided with means for measuring again the value of the same experimental parameter measured by the user during the experiment.

In another embodiment of the invention, the multifunction interface device is provided with means for determining the value of an experimental parameter using the characterizing relationship among the experimental parameters measured and given values for all of the other experimental parameters. In another embodiment of the invention, the multifunction interface device is provided with means for causing the value of an experimental parameter to be displayed on the display means.
In another embodiment of the invention, the multifunction interface device is provided with means for showing graphicalplots of measured and calculated experimental parameters versus other experimental parameters and functions of other experimental parameters, the nature of the graphical plots being specified by the user.
In another embodiment of the invention, the multifunction interface device is provided with means for showing on the display means a representation of the phenomenon selected from a plurality of phenomena that occur during the performance of the experiment using the experimental configuration using judiciously chosen numeric, iconic or other pictorial representations.
In another embodiment of the invention, wherein the phenomenon is selected from the following phenomena: (1) changes in the objects making up the experimental configuration including changes in size, shape, state, position, orientation, temperature, pressure, composition, and appearance; (2) changes in the relationships of the objects making up the experimental configuration; (3) the flow of energy within, into, and out of the objects in the experimental configuration; (4) the propagation of waves within, into, and out of the objects in the experimental configuration; (5) the flow of matter within, into, and out of the objects in the experimental configuration; (6) the flow of atoms, molecules, ions, and electrons within, into, and out of the objects in the experimental configuration; (7) the flow of other elementary particles not enumerated above within, into, and out of the objects in the experimental configuration; (8) the occurrence of electric and magnetic fields; and (9) the occurrence of temperature, density, and pressure gradients.

In another embodiment of the invention, the multifunction interface device is provided with means for guiding the user in the physical construction of the experimental configuration using a combination of textual and pictorial representations.
In another embodiment of the invention, in select applications, the multifunction interface device is provided with means for guiding the user in what signals are dynamically generated or processed by the computer by displaying the status of the signals on the captive port.
In another embodiment of the invention, in select applications, the multifunction interface device is provided with means for guiding the user in what software commands are dynamically used to program the computer to execute the said control tasks and drive devices connected to the captive port.
In another embodiment of the invention, the multifunction interface device is provided with means for recording, storing, transforming and generating data representing acoustic signals, including voice messages.
In another embodiment of the invention, the multifunction interface device is provided with means by which the user can change the operating speed of the pictorial representation of the experimental data relative to the operating speed of the actual performance by the experimental configuration.
In another embodiment of the invention, the device of the invention is adapted to be used by selecting an experiment to be performed; assembling the textual or pictorial representation of the experimental configuration; carrying out measurements in real time; then requesting that the pictorial representation of the experimental results be displayed either faster or slower than the real-time experiment.
In another embodiment of the invention, the device of the invention is adapted to be used for teaching science and engineering to a student by providing a means for displaying imagery; causing a plurality of objects to be pictured on the display means, the objects being apparatus, equipment, devices, materials, and supplies used in science and engineering; enabling the student to assemble a

plurality of the objects pictured on the display means into an operating pictorial representation of an operating experimental configuration, the experimental configuration being characterized by a relationship among a plurality of experimental parameters; enabling the student to simulate the performance of an experiment using the pictorial representation of the experimental configuration, an experiment being a method of measuring one of the plurality of experimental parameters by means of the experimental configuration, the operation of the pictorial representation of the experimental configuration being governed by the same relationship among the experimental parameters that characterizes the operation of the experimental configuration.
In another embodiment of the invention, the device of the invention can be used by changing the values of the experimental parameters each time an experiment is performed.
In another embodiment of the invention, the device of the invention can be used by measuring again the value of the same experimental parameter measured by the student during the experiment.
In another embodiment of the invention, the device of the invention can be used by determining the value of an experimental parameter using the characterizing relationship among the experimental parameters and measured and given values for all of the other experimental parameters.
In another embodiment of the invention, the device of the invention can be used by causing the value of an experimental parameter to be displayed on the display means.
In another embodiment of the invention, the device of the invention can be used by showing plots of measured and calculated experimental parameters versus other experimental parameters and functions of other experimental parameters, the nature of the plots being specified by the user.
In another embodiment of the invention, the device of the invention can be used by showing on the display means a phenomenon selected from a plurality of

phenomena that occur during the performance of the experiment using the experimental configuration.
In another embodiment of the invention, the device of the invention can be used for the following phenomenon: (1) changes in the objects making up the experimental configuration including changes in size, shape, state, position, orientation, temperature, pressure, composition, and appearance; (2) changes in the relationships of the objects making up the experimental configuration; (3) the flow of energy within, into, and out of the objects in the experimental configuration; (4) the propagation of waves within, into, and out of the objects in the experimental configuration; (5) the flow of matter within, into, and out of the objects in the experimental configuration; (6) the flow of atoms, molecules, ions, and electrons within, into, and out of the objects in the experimental configuration; (7) the flow of other elementary particles not enumerated above within, into, and out of the objects in the experimental configuration; (8) the occurrence of electric and magnetic fields; and (9) the occurrence of temperature, density, and pressure gradients.
In another embodiment of the invention, the device of the invention can be used by guiding the user in the construction of the pictorial representation of the experimental configuration.
In another embodiment of the invention, the device of the invention can be used by testing the student on his knowledge of the subject matter relating to the experiment.
In another embodiment of the invention, the testing step utilizes values of the experimental parameters, the method further comprising the step of selecting different values of the experimental parameters each time the student is tested.
In another embodiment of the invention, the device of the invention can be used by producing sounds appropriate to the existence and interaction of objects in an experimental configuration when the pictures of the objects in the pictorial representation of the experimental configuration exist and interact on the display means.

In another embodiment of the invention, the device of the invention can be used by enabling the student to cause data necessary for the assembly of the pictorial representation of the experimental configuration and the performance of an experiment to be displayed on the display means.
In another embodiment of the invention, the device of the invention can be used by enabling the student to change the operating speed of the pictorial representation of the experimental results relative to the operating speed of the experimental configuration. The interface of the invention is intended for use with any IBM compatible microcomputer and is capable of interfacing with the older as well as the newer architecture machines. The interface can be used as a data-acquisition tool with microcomputers that, based on the microprocessor chipsets used, are generally known as 286, 386, 486, Celeron, Pentium II, Pentium III and Pentium IV microcomputers.
In another embodiment of the invention, the multifunction interface device and the associated software is functional across a variety of computer operating systems inducing DOS, Windows®, and the like. An important feature of the invention is that the software and the hardware used are not limited to a specific operating system. Brief description of the accompanying drawings
The present invention will now be described with reference to the accompanying drawings wherein:
Figure 1 is a schematic diagram of the interface of the invention.
Figure 2 is a representation of the complete circuit of the multifunction interface device of the invention.
Figure 3 (a - d) shows the connection diagrams of the integrated circuits used in the invention.
Figure 4 is a schematic representation of the multifunction interface of the invention with a microcomputer and its use as a versatile microcomputer based laboratory instrument.

Figure 5 is a schematic representation showing the use of the Multifunction Interface of the invention for measurement of time-displacement characteristics of a moving object in real time according to one use embodiment of the invention.
Figure 6 is a schematic representation showing the use of the multifunction interface of the invention for the simultaneous measurement of force acting on an oscillating cart and its displacement in real-time.
Figure 7 is a schematic representation showing the measurement of velocity and acceleration using the multifunction interface of the invention. Detailed description of the invention
The multifunction interface device of the invention is connected to the microcomputer through a parallel port present on the microcomputer. This parallel port is a conventional component of every microcomputer and is normally used for communication of data with an external printer.
Referring now to the figures, figure 1 shows a schematic representation of one embodiment of the invention. The multifunction interface device shown therein comprises of at least one digital to analog converter 1, at least one analog to digital converter 2, a plurality of digital input/analog lines 3, digital input lines 4, digital output lines 5, a plurality of analog input lines 6, and at least one analog output line 7. The analog to digital converter 2, digital to analog converter 1, and the digital input/ output lines 3 individually communicate with a computer (not shown) through a parallel port provided thereon. As will be seen from Figure 2, the operation of the analog to digital converter, digital to analog converter and the digital I/Olines can be in tandem or independent. Dependant on the nature and the requirements of the experimental set up the interface also functions as a transmitter of instructions from the computer to the experiment set up. Instructions are relayed from the computer through the multifunction interface to the experiment set up and the results in the form of data relayed back again through the interface. Depending on the nature of the result signals, either of the analog to digital converter 2, the digital I/O bus 3, or digital to analog converter 1 can be used. The results are collected and collated on the microcomputer by means of dedicated software loaded

thereon and displayed on conventional display means. The parameters of the experiment set up can be varied according to the requirements of the user. The periodic transmission of results is collated.
Figure 2 is a circuit diagram of the multifunction interface of the invention.. As is seen from the figure, all three data transmission means comprising the digital to analog converter, analog to digital converter and the digital I/O bus are capable of operation simultaneously or independently. The digital to analog converter 1 communicates with the computer (not shown) through a tristate Schmitt trigger 4 and a parallel port plug connector 5. A voltage regulator 6 is provided to maintain a reference voltage over this portion of the circuit. The digital to analog converter communicates with the experiment set up through an external connector 7 which is in turn connected to the sensor/transmitter/signal conditioning circuit for the experiment set up. The operation of the experiment set up can be regulated/controlled through the digital to analog converter 1 without reference to the other components of the multifunction interface. For example, when a set of predetermined instruction sequence is loaded on to the computer, the multifunction interface receives appropriate digital signals through the plug connector 5. These signals are converted to analog form and transmitted to the experiment set up through the external connector 7 from digital to analog converter. The results obtained are received by the external connector and retransmitted back to the computer through the analog to digital converter 2.
The analog to digital converter 2 functions as a data acquisition component and is a monolithic CMOS device with an 8-bit analog-to-digital converter, 8-channel multiplexer and microprocessor compatible control logic. The analog to digital converter 2 uses successive approximation as the conversion technique. The converter 2 is provided with a high impedance chopper stabilized comparator, a 256R voltage divider with analog switch tree and a successive approximation register (not shown). The 8-channel multiplexer can directly access any of the 8-single-ended analog signals using a logic address. The device eliminates the need for external zero and full-scale adjustments. Easy interfacing to microprocessors is

provided by the latched and decoded multiplexer address inputs and latched TTL tristate outputs. Converter 2 offers high speed, high accuracy, minimal temperature dependence, excellent long-term accuracy and repeatability, and consumes minimal power. These features make this device ideally suited for a vast range of applications in data-acquisition, process and machine control.
Table 1 below provides the references and the component descriptions. Table 1: References and component description
(Table Removed)
The parallel port pin assignments on the DB 25 pin connector are indicated in Table 2.Table 2: Parallel Port and DB 25 Connector Pin Assignments
(Table Removed)

The digital to analog converter 1 used in this embodiment is a monolithic 8-bit high-speed current-output digital-to-analog converter with a settling time of 100 ns. The reference-to-full-scale current matching is better than ± LSB thereby eliminating the need for a full-scale trim. The non-linearity over temperature is better than ±0.1% thereby minimizing system error accumulations. The noise immune inputs of the digital to .analog converter 1 accept TTL levels with logic pin VLC grounded. The digital to analog converter circuit operates from a reference voltage of VREF - +5V and a power supply of ± 15 V and in positive low impedance output mode with the current output loun (pin 4) connected to the inverting input of the operational amplifier while the complementary current output IOUT (pin 2) is grounded. In this circuit, RREF=R1=3.3 KΩ Hence IREF=VREF/RREF = 5V/3.3K Ω so that
(Equation Removed)

With RF=RREF, Vom = IFSRF K^VREF-
Thus the positive full-scale value of the output is 4.98 V. The digital inputs are connected to bits D0-D7 of Data Port A of the parallel port of the microcomputer via the tristate trigger 4.
The analog to digital converter 2 has an 8-bit resolution and a conversion time of 100 µ s at a clock frequency of 640 kHz. It operates with a 5 VDC voltage reference; requires no zero or full scale adjust; has an analog input range of 0-5V and outputs that meet TTL voltage level specifications. It has a total unadjusted error of ±1/2 LSB and ±1 LSB. It requires a single power supply of 5 VDC and has low power consumption at 15 mW. The device contains an 8-channel single-ended analog signal multiplexer. A particular input channel is selected by using the address lines to select any channel. The address is latched into the decoder on the low-to-high transition of the address latch enable signal. The logic address for each analog input channel is given in the Table 3 below.
Table 3: Logic address for each analog input channel
(Table Removed)

The circuit is operated with Vcc=5V, VDC=VREF(+)-5V and VREF(-)=GND. Thus, when an analog input equals VREF{+), the digital output is 255. The eight analog inputs are connected to the ADC via the input lines IN0-IN7. The ADC

requires a clock signal to control the conversion that is created using a Schmitt triggered inverter 8.. With R=1M Ωand C=l µ F, in this circuit, the clock frequency is ~0.7/RC = 0.7 M Hz. The signals for accomplishing the analog-to-digital conversion are generated by the microcomputer under software control and are available at the parallel port. These are made available to the converter 2 through the tristate buffer 4'. Table 4 summarizes the connections between the crucial ADC signals and the bits controlling these from the parallel port. Table 4: Parallel Port Signals Assigned to Control the ADC operation
(Table Removed)

Control port outputs CO, Cl and C2 select the channel at which the analog voltage is to be converted. The Start Conversion and the ALE are tied together and connected to bit C3 of the control port. A transition to a high logic level at this pin latches the address of the channel to be converted and a high to low transition starts the conversion. At the end of conversion, EOC and bit 57 of the status port become high. Because of paucity of input data lines on the parallel port, the data is read as the high and the low nibbles by the bits S3, S4, S5 and S6 of the status port. The nibble is selected by the bit C2 of the control port. When C2 is low, the low nibble of the ADC outputs is read. When C1 is high, the high nibble is read.
The parallel port provides very few digital input/ output lines. Inasmuch as the 8-bit data port D0-D7 is reserved for operating the digital to analog converter 1, the analog to digital converter circuit optimally utilizes the remaining I/O lines. Thus the control port bit C1 is used both for address selection and selecting the

nibble to transfer to the parallel port. Further, is one waits long enough for a conversion to be completed, it is not necessary to read the status of the end-of-conversion signal. Hence, it is possible to release this for use as an independent digital input line. If only four analog channels are used, bit CO can also be released for use as an independent digital output line. For rapidly changing analog inputs, it is necessary that the analog input remain stable during the process of conversion. To ensure this, a sample-and-hold integrated circuit can be provided in the circuit. The circuit can also include conventional protection circuits to minimize the chances of damage by inappropriate usage.
Figure 3 (a - d) shows the connection diagrams of the integrated circuits used in the invention.
Figure 3 a is a schematic top view of the digital to analog converter 1 showing each of the input line and the respective output lines, for supply of power, data transmission including instructions from the microcomputer (not shown) to the physical system and the results from therefrom back. The operation of the converter has been explained with reference to figure 2.
Figure 3 b is a schematic top view of the analog to digital converter 2 showing each of the input lines and the respective output lines, for supply of power, data transmission including instructions from the microcomputer (not shown) to the physical system and the results from therefrom back. The operation of the converter has been explained with reference to figure 2.
Figure 3 c is a schematic top view of the tristate Schmitt Trigger non-inverting ocatal buffer showing each of the input line and the respective output lines, for supply of power, data transmission including instructions from the analog to digital converter 2 to the physical system and the microcomputer. The operation of the buffer has been explained with reference to figure 2.
Figure 3 d is a schematic top view of the Schmitt Trigger inverting Hex buffer showing each of the input line and the respective output lines, for supply of power, data transmission instructions from the analog to digital converter 2 to the physical

system and the microcomputer. The operation of the buffer has been explained with reference to figure 2.
Figure 4 is a schematic representation of the multifunction interface of the invention with a microcomputer and its use as a versatile microcomputer based laboratory instrument.
As shown in the figure, the microcomputer 10 is loaded with dedicated software capable of performing a range of functions such as measurement of analog voltage, control of real world devices, logical sequencing of digital signals, waveform generation, frequency generation and measurement, and the like. The microcomputer 10 is connected to the multifunction interface 11 by means of a external plug connector through a parallel port thereon for communication of data with the experimental set up physical system 12.. The construction of the multifunction interface 11 is as described above with reference to both Figures 1 and 2. Additional signal conditioning circuits 13 and 14 are provided connected to the analog to digital converter 2 and the digital to analog converter 1 respectively. The two converters 1 and 2 are connected in turn to the physical system 12 through transducers/sensors 15 and 16.. The physical system can be any experimental set up such as a mechanical system, electrical system, electronic system, active/passive device, acoustic system, thermal system, chemical system, magnetic system, optical system, spectroscopic system, radioactive system, biological system, human system, geo- or earth system, or atmospheric system, depending on the nature of the experiment to be carried out. While only one transducer/sensor 15, 16 each are shown, a multiplicity of transducers/sensors may be utilised depending on the number of parameters to be monitored/controlled by the microcomputer 10 through the multifunction interface 11.. The signal conditioning circuits 13 and 14 comprise of conventional circuits such as buffers, gain amplifiers, current to voltage converters, voltage level shifters, instrumentation amplifiers, difference amplifiers, and the like.
The multifunction interface 11 may also be directly connected to the physical system, 12 through a digital I/O bus provided in the interface 11. As explained

above, the two converters 1 and 2 and the digital I/O bus are capable of acting individually or in tandem depending on the nature of the experimental set up.
The microcomputer 10 is loaded with dedicated software capable of performing or executing a series of instructions at the choice of the user. The physical system 12 is responsive to the instructions received from the computer 10 through the multifunction interface 11. As is evident, the instructions can be varied to feed in different variables as a function of time or conditional to certain results being obtained in the experimental set. Data communication is two-way through the interface 11. The instructions are relayed to the physical system 12 on one hand and the results obtained are relayed back to the microcomputer 10 on the other hand. The construction of the interface 11 wherein the three data transmission means (the two converters 1 and 2 and the digital I/O bus 3) are connected individually with both the computer 10 and the physical system 12 and with each other enables a plurality of parameters being measured at one time from different real world instruments present in the physical system 12.
A major lacuna in physics laboratories, particularly in India, is the absence of experimentation in kinematics. It is evident that online graphs of motion are extremely useful to address common misconceptions about motion and enhance understanding of kinematics. The multifunction interface when connected to the ultrasonic motion detector in the package provides a powerful method for recording displacement-time graphs of an object, be it an arbitrarily moving student herself; a cart moving down a ramp; or a cart constrained by two springs set oscillating on a horizontal track.
Figure 5 is a schematic representation showing the use of the multifunction interface of the invention for measurement of time-displacement characteristics of a moving object in real time according to one use embodiment of the invention. The detailed explanation of this figure is provided in Example 1. In this figure the experimental set up is done for measurement of position of a dynamic cart in realtime and display of displacement-time (x-t), velocity-time (v-t) and acceleration-time (a-t) graphs. The motion detector sensor could consist of an ultrasonic receiver-

transmitter assembly located at the same position. To record the displacement of a moving object, the microcomputer interface sends a digital output signal that activates the transmitter to send burst of ultrasonic pulses. These are reflected back from the object moving directly and unobstructed in front of it. The receiver signals the arrival of the echo by generating a digital signal that is input to the computer. The time it takes for a echo to return from a distance x is determined by a generic pulse counting procedure that calculates the time elapsed between the two signals. Then the position at a particular time is simply calculated as x=vt/2 where v is the speed of the transmitted wave. This procedure is repeated to monitor the motion. Given alongside is the spalcement-time graph of a cart that is initially at the position xo with respect to the position of the motion detector at time zero and then moves steadily away from it slowly to a position x A , stands still for an interval dT and then returns to its initial position with a different constant speed.
Figure 6 is a schematic representation showing the use of the multifunction interface of the invention for the simultaneous measurement of force acting on an oscillating cart and its displacement in real-time. The detailed explanation of this figure is provided in Example 2. The multifuction interface permits simultaneous measurement of the force acting on the cart as its motion is being recorded. These data allow real-time display of displacement-time (x-t), force-time (F-t) and force-displacement (F-x) graphs.
The force transducer used here is the commonly available strain gauge which is glued to the surface of a beam to which are attached the two springs. This beam is mounted on the cart. As the cart oscillates, so does the beam. The strain thus produced causes a change in the resistance of the sensor that is a direct measure of the force experienced by the cart. Thus the underpinning principle of the measurement is to convert the change in resistance to an analog voltage signal appropriate for measurement by the analog to digital converter of the interface. The signal conditioning circuit for this is standard. The strain gauge is used in a typical off-balance Wheatstone Bridge configuration with the off-balance voltage being measured by the three op-amp instrumentation amplifier.

Figure 7 is a schematic representation showing the measurement of velocity and acceleration using the multifunction interface of the invention. A simple method for measuring the instantaneous velocity or acceleration of a moving object is by using the multifunction interface as an event timer to measure the time it takes for the object to traverse specific distances. Figure 7 is the measurement set up for this task. The detailed explanation of this figure is provided in Example 1.
The sensor here comprises a photo-gate 71 fabricated using an infrared source-sensor pair but could be any proximity sensor. A slotted card 72 is mounted on the car 73. As the slotted card 72 goes through the photo-gate 71, the infrared signal is interrupted each time it encounters an edge 74. Then the output from the sensor 71 changes state. The signal conditioning circuit (photo-interrupt switch circuit) 75 records this as a digital logic high to low voltage transition. This information is transmitted to the microcomputer 10 through means of a digital I/O bus 3 provided in the multifunction interface 11. By finding the time between these transitions, the time taken for the length of the card 72 to pass the photo-gate 71 is easily calculated and thus the instantaneous velocity. Using two such sensors 71 and 71' located at a distance x = xi - xi apart, the acceleration can also be determined.
The same principle can be employed for determining acceleration due to gravity by dropping a ball from rest and determining the time it takes for it to pass through two photo-gates fixed a known distance apart. Using a slotted logical optical switch, the setup can also be used to determine the angular frequency of rotation of a motor by mounting a shaft with a narrow slit carved in it. Each complete rotation would generate a voltage transition pulse. Determining the time between two consecutive pulses would give a continually updated value of the angular frequency.
In one preferred embodiment, the interface device of the invention includes the following essential units:
• 8-bit digital-to-analog converter;
• an 8-bit 8-channel analog-to-digital converter; and
• a set of digital input and output lines.

The invention relies on a systems approach to laboratory procedures by recognizing that scientific experimentation typically involves a set of procedures each of which can be automated. Thus, the dedicated software provided on the microcomputer (the terms computer and microcomputer herein are used interchangeably) includes a database of select generic tasks involved in predetermined laboratory procedures. The software is menu driven and typically provides the following options depending on the user requirement:
1. Tutorials: These provide a sequence of exercises that aim to introduce the user to generic operations possible using the multifunction interface. Broadly, these entail generating an output digital signal according to a prescribed logical sequence; detecting a digital input signal or switching action; controlling real world devices; timing interval between events; generating a voltage waveform; measuring frequency of a given voltage waveform; and measuring and calibrating analog voltage output from a variety of transducers and sensors. A special feature of the tutorials is that the essential principle and crucial instructions for programming the parallel port are displayed on the screen in real time in the context of the task on hand. Knowledge of these few simple measurement techniques empowers the user to set up a vast range of scientific investigations.
2. General Purpose Data-Acquisition Programs: These allow the microcomputer to be used as a digital voltmeter, a storage oscilloscope, a signal generator or all three together. As an illustration, the program can be used to investigate the time-domain response of any physical system by recording variations in time of as many as eight physical quantities. In addition, the program can also be used to determine the frequency-domain response by measuring the output when the system is subjected to an input voltage signal waveform of varying frequency as well as the parameteric response wherein variations in one physical quantity with respect to another can be measured.
3. Dedicated Application Programs: These programs are specially written to run a comprehensive list of specific science experiments. The data gathered in analog measurements is displayed graphically. Data input when crucial system parameters

are varied can also be superposed. A significant feature is that data can be saved in a format that allows it to be exported to an Excel spreadsheet for further manipulation and analysis.
The scope of measurements enabled by the multifunction interface of the invention is tremendous. For example, core experiments in physics such as in kinematics, elementary dynamics, mechanical oscillators, acoustic systems, wave optics, thermal systems, basic electrical systems, electric networks, electromagnetic systems and electronic networks can be done with substantial accuracy of results. Each theme is developed through several carefully crafted exercises and follows a robust teaching-learning path for enhancing understanding of the underlying concepts. It must be understood that the device of the invention has applicability in teaching of all areas of science in view of the versatility of the invented device.
Figure 4 gives a schematic block diagram of measurement and control applications. The hardware functional blocks necessary in applications are indicated in the schematic as generic functional blocks accompanied by an illustrative list of what the actual circuit would entail. It is worth emphasizing that easy of a comprehensive range of sensors and transducers transfers to the interface a capacity for real-time measurement of just about any physical quantity of interest in specific science domains as well as multidisciplinary contexts.
As explained above, the device of the invention comprises of a plurality of analog channel, a plurality of analog to digital converters, an analog output channel, at least one digital input/output channel, a digital to analog converter.
The digital channels used in the invention preferably comprise eight analog input channels for connecting a vast range of sensors such as temperature, light, force, magnetic field, pressure, and the like, one analog output channel, two digital I/O channels (the number of digital I/O channels depends on the experimental set up).
The multifunction interface device serves primarily as a teaching instrument: a device with simple design that highlight the principle of measurement, have no more than a appropriate level of sophistication and the functional aspects of which

are transparent and easy to comprehend. For classroom usage, the modules have a
robust packaging and incorporate protection circuits to avoid accidental damage to
the microcomputer.
The complete Interfacing Package includes several other hardware modules
that add value to the multifunction interface. A partial list is provided in Table 5
below:
Table 5: Hardware Items in the interfacing package accompanying the Multifunction Interface Device: Illustrative List of Dedicated Experimental Setups: Examples from Physics
Item List:
(Table Removed)
The following examples are merely illustrative of the device of the invention and are not to be construed as limiting the scope of the invention. As will be clear to any person skilled in the art, the device of the invention also finds application in all fields of science, whether in an academic environment or in an industry environment. Example 1 Measurement of displacement-time characteristics (Figure 6):
In this example, an experiment to measure the position of a dynamic cart in real-time was carried out. The motion detector sensor comprised of an ultrasonic receiver-transmitter assembly located at one fixed position. To record the displacement of a moving object (cart), a digital output signal was sent from the microcomputer interface to activate the transmitter to emit a burst of ultrasonic pulses. The ultrasonic pulses were reflected back from the object moving directly and unobstructed in front of it. The receiver signalled the arrival of the echo by generating a digital signal that was input to the computer. The time taken for an echo to return from a distance x was determined by a generic pulse counting procedure that calculates the time elapsed between the two signals. Then the position at a particular time was simply calculated as x=vt/2 where v is the speed of the transmitted wave. This procedure was repeated to monitor the motion. In Figure 6, the displacement-time graph of the cart that is initially at the position xo with respect to the position of the motion detector at time zero and then moves steadily away from it slowly to a position x A , stands still for an interval dT and then returns to its initial position with a different constant speed. Example 2 Measurement of Displacement-time and Force-Time Characteristic (Figure 7):
The multifuction interface permits simultaneous measurement of the force acting on the cart as its motion is being recorded. As can be seen from Figure 7, the cart is constrained by two springs to oscillate on a track. These data allow real-time display of displacement-time (x-t), force-time (F-t) and force-displacement (F-x) graphs. The force transducer used in this example is a commonly available strain gauge which is glued to the surf?ce of a beam to which are attached the two springs.
This beam is mounted on the cart. As the cart oscillates, so does the beam. The strain thus produced causes a change in the resistance of the sensor that is a direct measure of the force experienced by the cart. Thus the underpinning principle of the measurement is to convert the change in resistance to an analog voltage signal appropriate for measurement by the analog - digital converter of the interface. The signal conditioning circuit used for this function is conventional. The strain gauge is used in a typical off-balance Wheatstone Bridge configuration with the off-balance voltage being measured by the three op-amp instrumentation amplifier. Example 3 Measurement of Instantaneous Velocity and Acceleration (Figure 8):
A simple method for measuring the instantaneous velocity or acceleration of a moving object is by using the Multifunction Interface as an event timer to measure the time it takes for the object to traverse specific distances. Figure 8 is the measurement set up for this task.
The sensor used herein is a photo-gate fabricated using an infrared source-sensor pair. However, any conventional proximity sensor can be used. A slotted card is mounted on the car. As the slotted card goes through the photo-gate, the infrared signal is interrupted each time it encounters an edge. Then the output from the sensor changes state. The signal conditioning circuit records this as a digital logic high to low voltage transition. By finding the time between these transitions, the time taken for the length of the card to pass the photo-gate is easily calculated and thus the instantaneous velocity. Using two such sensors located at a distance x = xi -X2 apart, the acceleration can also be determined. Example 4 Measurement of acceleration due to gravity:
The same principle as in Example 3 was used to determine acceleration due to gravity by dropping a ball from rest and determining the time it takes for it to pass through two photo-gates fixed a known distance apart. Using a slotted logical optical switch, the setup can also be used to determine the angular frequency of rotation of a motor by mounting a shaft with a narrow slit carved in it. Each complete rotation would generate a voltage transition pulse. Determining the time
between two consecutive pulses would give a continually updated value of the angular frequency.
The package has been designed to remove the mystique from the new technology and is suitable for teaching the rudiments of interfacing in a student laboratory as also teacher training programs. Additionally, the modules provide building blocks that add up to be powerful instruments achieving state-of-the-art for a gamut of complex physical measurements. Thus in a dual advantage, the package can be used by both the novice and the advanced user. It can be used in both, traditional laboratory settings and more challenging project-based learning environments. It can be of use at the school and college level as also of value to advanced laboratories.

We Claims -
1. A multifunction interface device for use, inter alia in conducting a pluarilty of laboratory experiments comprising one or more signal generation means responsive to a sensor means provided on an experiment set up in order to generate signals indicating a specific result required or obtained therefrom in machine readable form, said one or more signal generation means coupled to one or more signal transmission means, said transmission means transmitting said signals to a microcomputer through a captive port on said microcomputer.
2. A multifunction interface device as claimed in claim 1 wherein said signal generation means comprises an analog or digital signal generation means.
3. A multifunction interface device as claimed in claim 1 wherein said signal transmission means comprises of an analog to digital converter, a digital to analog converter, a plurality of digital input/output channels or one or more of any of the above.
4. A multifunction interface device as claimed in claim 3 wherein said analog to digital converter is adapted to to convert said analog signals into digital signals readable by a microcomputer, said interface being provided with digital input signal means connected to said analog to digital converter to transmit said digital signals to said microcomputer through a responsive parallel port provided on said microcomputer, a digital output signal means connected to saod computer for receiving instructions from said computer and forward it to the experiment set up, said digital output signal means forwarding said instructions by means of a digital to analog converter.
5. A multifunction interface device as claimed in claim 3 wherein each of said analog to digital converter and digital to analog converters is provided with a captive signal conditioning circuit.

6. A multifunction interface device as claimed in claim 5 wherein said signal conditioning circuit is selected from a buffer circuit, off balance bridge, gain amplifier, difference amplifier, instrumentation amplifier, voltage level shifter, current to voltage converter, multiplexer, filter, rectifier, differentiator, integrator or multiplier.
7. A multifunction interface device as claimed in claim 1 wherein the sensor means is selected from a conventional linear displacement, angular displacement, motion, proximity, speed, acceleration, force, strain, rotation, voltage, current, resistance, conductance, light intensity, sound intensity, magnetic field, radioactivity, temperature, radiation, pressure, flow, humidity, turbidity, gas, pH sensors and the like.
8. A multifunction interface device as claimed in claim 1 wherein the digital input means comprises of a digital input/output bus comprising of at least one input/output channel.
9. A multifunction interface device as claimed in claim 1 wherein said interface is provided with a gate circuit operatively associated with any or all of said analog to digital converter, digital to analog converter, input output lines in order to transmit a user-determined set of instructions to the physical system.
10. A multifunction interface device as claimed in claim 1 further including a digital-to-analog converter; an analog-to-digital converter; and a corresponding set of digital input and output lines, a plurality of analog input channels connectable and responsive to a plurality of sensory devices in order to measure and read input sensor data; at least one analog output channel responsive to the said plurality of analog input channels, and two or more digital input/output channels, said analog output channel being operatively associated with a analog to digital converter to convert the analog output data into a digital data stream,

said digital stream being fed into a microcomputer by means of a digital input/output bus, said analog to digital converter being provided with a multiplexer and a microprocessor compatible logic circuit.
11. A multifunction interface device as claimed in claim 1 further comprising means
for changing the values of the experimental parameters each time an experiment
is performed.
12. A multifunction interface device as claimed in claim 1 further comprising a means for measuring the value of the same experimental parameter measured by the user during the experiment.
13. A multifunction interface device as claimed in claim 1 wherein further comprising a means for determining the value of an experimental parameter using the characterizing relationship among the experimental parameters and measured and given values for all of the other experimental parameters.
14. A multifunction interface device as claimed in claim 1 wherein further comprising a means for causing the value of an experimental parameter to be displayed on the display means.
15. A multifunction interface device as claimed in claim 1 wherein further comprising a means for showing plots of measured and calculated experimental parameters versus other experimental parameters and functions of other experimental parameters, the nature of the plots being specified by the user.
16. A multifunction interface device as claimed in claim 1 further comprising a
means for showing on the display means a phenomenon selected from a plurality
of phenomena that occur during the performance of the experiment using the
experimental configuration.

17. A multifunction interface device as claimed in claim 1 wherein the phenomenon is selected from the following phenomena: (1) changes in the objects making up the experimental configuration including changes in size, shape, state, position, orientation, temperature, pressure, composition, and appearance; (2) changes in the relationships of the objects making up the experimental configuration; (3) the flow of energy within, into, and out of the objects in the experimental configuration; (4) the propagation of waves within, into, and out of the objects in the experimental configuration; (5) the flow of matter within, into, and out of the objects in the experimental configuration; (6) the flow of atoms, molecules, ions, and electrons within, into, and out of the objects in the experimental configuration; (7) the flow of other elementary particles not enumerated above within, into, and out of the objects in the experimental configuration; (8) the occurrence of electric and magnetic fields; and (9) the occurrence of temperature, density, and pressure gradients.
18. A multifunction interface device as claimed in claim 1 further comprising a means for guiding the user in the physical construction of textual or pictorial representation of the experimental configuration using hardware blocks and actual performance of the experiment in real-time with possibilities of both, realtime and off-line display of diverse representations of data gathered and the results of experiment.
19. A multifunction interface device as claimed in claim 1 further comprising a means for storing data representing voice messages and sounds and a means for transforming the stored data into voice messages and sounds.
20. A multifunction interface device as claimed in claim 1 further comprising a means for parsing a given algebraic function and generating a corresponding analog signal.

21. A multifunction interface device as claimed in claim 1 further comprising a means for parsing a function expressed as a table of numeric values and generating a corresponding analog signal.
22. A multifunction interface device as claimed in claim 1 further comprising a means for multiplexing and measuring up to eight different analog signals each at two channels of the on-board analog-to-digital converter, providing measurements from an array of sixteen sensors.
23. A multifunction interface device as claimed in claim 1 further comprising a means for guiding the user as to what signals are dynamically generated or processed by the computer by displaying the status of the signals on the captive port.
24. A multifunction interface device as claimed in claim 1 further comprising a means for guiding the user in software commands that are dynamically used to program the computer to execute the said control tasks and drive devices connected to the captive port.
25. A multifunction interface device for use, inter alia in conducting a pluarilty of laboratory experiments substantially as herein described with reference to and as illustrated in the accompanying drawings.