FIELD OF THE INVENTION
The present invention is directed to an online system for control and monitoring of finishing
groups of Rail and Structural Mills(R & SM). More particularly, the present invention is
directed to a PLC based centralized automation and control system comprising comprehensive
networking of the nine different nodes including two PLCs and six remote I/O nodes and one
PLC programming station covering four groups (Group 1 to Group 4) in two machine halls (2
& 3) through a Dual Redundant Communication Network covering a stretch of 1.5 Km.
Advantageously, the present invention is directed to integrate the automation system of the
R & SM finishing groups covering 109 mechanisms that include Walking Beam, Rack Pusher,
Pneumatic Pusher, Tilter and Roll table etc. The automation system having the networking of
nodes involving 415 inputs and 325 outputs, involving various inputs from control pulpits are
connected to the remote I/O units placed near to the control desk. Inputs available in panels
at Machine halls have been taken to PLC panel installed in the respective machine halls, such
as to implement customized application software based control of various mechanisms
through the existing power devices through output cards placed in PLC panels. Importantly, a
soft logic based change over from 13m and 26m rails and vice versa is introduced. The above
arrangement of the integrated networking of control pulpits and logic control software,
replacing hardware based control enabling change over of 13m-26m campaign as well as
auto operation of few mechanisms of the groups to enhance control and operational
efficiency. Advantageously also, the above said centralized control system through signal
connectivity to nearest node of the network substantially reduced the requirement of cabling
work, favored easy detection of faults and reduced down time for maintenance, making wide
application of such automation and control system for finishing group mechanisms for RSM or
similar other plants with significant economic advantages.
BACKGROUND ART
The conventional processing of equipments and control signals thereof for Rail finishing area
having immense importance in testing and quality assurance of rail products produced. This
area comprises on one hand testing and finishing machines like Rail straightening machine,
eddy current testing machine, ultra sonic testing machine, rail end cutting and milling
machines on the other hand require precise electronic control for operation and maintenance
of such production and/or testing machines for meeting desired productivity and quality
criteria. In addition to this a large number of transfer beds and roll tables along with

equipment such as stoppers, titters, walking beams etc. are installed for handling and
transportation of rails in the finishing bay.
Most of these equipments in this area in existing setup is working on relay logic control in
stand alone mode. The relay logic based system suffer obsolescence due to inherent
inefficiency in terms of difficulty of maintenance and trouble shooting in case of breakdowns,
causing loss of production and declining productivity. In addition to this the existing hardware
based control system the vast network of control cables interconnecting the various
independent control pulpits and the control elements located at two machine halls at a large
distance from each other are prone to frequent failures. This leads to excessive downtime to
localize the faults and subsequent replacement/rectification of cables and resultant failure of
control circuitry.
Also the equipments, set-ups and related process and controls thereof undergoes a
changeover from every month 13 meter to 26 meter length of finished rails or vice versa.
This change over necessitates multiple modifications in Rail finishing groups for their
operations in combination. A lot of changes in electrics are also required to be carried out for
implementing the changeover. These changes needed to be undone and previous
arrangement restored, once processing of a particular length say, 26 meter was over. Each of
the three existing groups in R & SM plant comprises of mechanisms like walking beam, rack
pushers, rail cutting m/c. and rail milling m/c. Here rails are milled at one end and is cut
other end ensuring exact finished length. Milling and cutting operation are carried out at 90°
angles so that the cut/milled surfaces are normal to longitudinal rail axis. After this, rail is
transported into inspection beds for visual inspection. Identical operations are carried out in
other two groups. It is experienced in the existing art that any fault occurring in any of the
mechanisms affects the processing of rails in the finishing area and absence of any on-line
fault diagnostics results into extended delay in attending and rectification of the associated
problem.
There has been thus a persistent need in the operation and control for
equipments/mechanisms engaged in production and inspection of rails of varied finished
lengths at different stages of processing and testing, to develop a centralized PLC based
control system implemented through a Dual Redundant Communication Network operatively
connecting the panels at each control pulpits connected to the remote I/O units placed near
to the control desk, so as to favor on-line fault diagnostics of different mechanisms and easy

adaptability of changeover from 13m to 26m and vice versa as and when needed, so as to
improve product quality, reduced downtime and improved productivity in R & SM plants.
OBJECTS OF THE INVENTION
The basic object of the present invention is thus directed to a centralized automation system
for on-line controlling and monitoring of the various input and output from the respective
control pulpits and the corresponding remote I/O units, involving PLC based control interfaced
with soft logic, through a dual redundant communication network connecting a plurality of
nodes comprising the said PLCs, remote I/O inputs connected to individual control pulpits,
and a PLC programming station.
Another object of the present invention is directed to a centralized automation system for
controlling and processing of various inputs/outputs relating to the equipments for production
and testing/inspection of products/rails favoring easy and efficient control of processes for
manufacturing and testing of Rails and structural mills, easy change over of rail length as
needed and also online fault diagnosis to minimize down time for maintenance, thus
improving the productivity and quality of the R& SM plants in steel plants.
A further object of the present invention is directed to said centralized PLC based control of
equipments and processes, connects selectively deployed PLCs to a number of remote I/O
nodes connecting individual control pulpits of each group of machines so that such PLCs and
another PLC programming station covering each of four such groups, operatively provide
desired centralized automation system for the R & SM plant.
Another object of the present invention is directed to a centralized PLC based automation and
control system for control of parameters relating to equipments and processes for production
and quality assurance of rails of different finished lengths produced wherein said integrated
dual redundant communication network connecting the nodes, elimination of control cables
from various control pulpits to machine halls reduce the overall cable requirement.
A still further object of the present invention is directed to a centralized PLC based
automation system for online control and monitoring of parameters relating to equipments
and processes for production and quality assurance of rails of different finished lengths
wherein the change over of 13m to 26 m rail lengths is achieved with minimum time,

complexity and cost, favoring reduced interruption in production, involving soft logic control
replacing the convention hardware based control of mechanisms in independent groups.
A centralized PLC based automation and control system for control of parameters relating to
equipments and processes for production and quality assurance of rails of different finished
lengths wherein the system and network of nodes favor automatic fault diagnostics of
mechanisms/cables favor reducing downtime of plant and simple and prompt rectification
and/or replacement/maintenance at less cost involving less manpower.
SUMMARY OF THE INVENTION
The basic aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) comprising
(i) programmable logic controllers (PLC) based centralized control and monitoring
for ease of maintenance & reducing downtime.
(ii) remote I/O stations at distributed locations for inputting and outputting various
control parameters.
(iii) plurality of nodes connected through dual redundant communication network;
and
(iv) means adapted for 13 to 26 meter rail change over through programmed logic
controllers.
A further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) comprising, a network
connecting plurality of nodes for control of facilities in multiple machine halls of RSM,
comprising of PLCs, Remote I/O and a PLC programming station for operative control on
mechanisms/functions of various finishing groups in different machine halls which are
distanced from one another;
said network being an integrated dual redundant communication network connecting the
selective numbers of communicating nodes;

means to interface with soft logic for operative control and change over of rail length from
13 m to 26 m and vice versa, as and when required;
said network adapted for signal exchange to select and implement desired process
parameters between respective nodes through programmed logic control means adapted to
generate commands, enabling easy and fast fault diagnosis and repair.
A still further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) comprising
a network connecting nine nodes for control of facilities in two machine halls of RSM,
comprising two PLCs, six Remote I/O panels and one PLC programming station for
operative control on mechanisms/functions of finishing Group 1 to Group 4 in different
machine halls at large distance apart;
said network being an integrated dual redundant communication network connecting
the specified number of communicating nodes;
said system adapted to be interfaced with soft logic for operative control and change
over of rail length from 13 m to 26 m and vice versa, as and when needed;
said network adapted to signal exchange to select and implement desired process
parameters between respective nodes through soft logic generated commands,
enabling easy and fast fault diagnosis and repair.
Another important aspect of the present invention directed to said system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) wherein one of the two PLCs is
connected to three remote I/O units in one machine hall and another PLC is connected to
another set of three remote I/O units in a separate machine hall having panels near the
operator's control desk at the pulpits and are networked.
A still further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM), wherein one said PLC extends
control to the mechanisms/processes of two Groups in a machine hall, with command inputs
from plurality of posts connected to remote I/O unit, including those of inspection stages.

A still further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) wherein another said PLC
extends control to the mechanisms/processes of another two groups in another machine hall,
with all command inputs from the operatively connected control posts including those of
inspection stages and respective remote I/O units .
A still further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) wherein said network comprises
interfacing the 24 Vdc low voltage signals of PLC with the 220Vdc supply based field system
for each individual input and output.
According to yet another aspect of the present invention directed to a system for controlling
and monitoring finishing groups of Rail and Structural Mills (RSM) wherein, said programmed
logic control commands are adapted for development and implementation through PLC
application software for operation of all equipments of various mechanisms like Transfer
beds, Roll Table, Dogsink, Stopper,Walking Beam, Rack Pusher, Pneumatic Pusher & Tilter.
A further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) wherein control outputs such as
Dogsink and Stopper are operatively controlled from their nearest Remote I/Os, instead of
main PLC.
An yet further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) wherein signal exchange
between the respective nodes and the PLC in a Group are carried out through said dual
redundant communication network wherein separate cable routes chosen carefully to avoid
any interference and/or simultaneous breakage/failure of communication network cable,
ensuring enhanced reliability.
A still further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) wherein said dual redundant
communication network are adapted to eliminate use of control cables from control pulpits to
machine halls.
A still further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) comprising control net protocol

with desired bus speed for interconnection of remote I/O nodes with respective individual
PLCs and Ethernet communication for inter-connection of PLCs and the programming unit to
keep the architecture open for up-gradation in future and also interfacing with other systems
for shop-wise MIS.
A still further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) wherein, selective hardware
configurations are provided for the PLC panels, and the respective Remote I/O units
communicating with selective numbers of corresponding pulpit control desks to ensure
effective integration and signal communication for desired functional automation and control
of process parameters for RSM finishing groups connected in said dual redundant
communication network.
A still further aspect of the present invention is directed to a system for controlling and
monitoring finishing groups of Rail and Structural Mills (RSM) wherein said dual redundant
communication network comprises of coaxial communication cable and CAT6 Ethernet
communication cable, for connecting the nodes of the centralized automation/control system.
According to a further aspect of the present invention is directed to a system for controlling
and monitoring finishing groups of Rail and Structural Mills (RSM) wherein, the input and out
put data and the feed back response data from the operating devices, enable on-line fault
diagnostics for critical parameters favoring reducing downtime for repair/maintenance.
BRIEF DESCRIPTION OF THE ACCOMPNYING FIGURES
Figure 1: is the schematic illustration of the PLC based automation system according to the
present invention, of RSM finishing group facilities in machine halls for production and quality
assurance of rail sections of variable lengths (13m and 26m Rails)
Figure 2: is the schematic illustration of the PLC networking scheme of the finishing group
automation system according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING FIGURES
Reference is first invited to the accompanying Figure 1 that schematically illustrates the PLC
based automation system according to the present invention for control of operations relating
to production/quality assurance of RSM finishing group. The present system of automation*
and control is adapted to control equipments and processes covering Group 1 to Group 4
involving two PLCs, six nodes connected to remote I/O units comprising selective numbers of
mechanisms and the individual control pulpits connected to such nodes such that the Inputs
available in panels at Machine halls have been taken to PLC panel installed in the respective
machine halls, such as to implement customized application software based control of various
mechanisms through the existing power devices through output cards placed in PLC panels.
The disclosed technical advancement in the present invention thus provides for an
automation system for control and monitoring of R & SM finishing Groups operations
comprising in a representative embodiment of the invention the following features:
1. Two Programmable Logic Controller (PLCs) for centralized control and monitoring of
mechanisms and test/inspection and communicating input/output or feedback data,
for ease of maintenance and reducing downtime.
2. Six Remote I/O stations at distributed locations for inputting and outputting various
control parameters for the individual equipment through pulpit control posts.
3. All such 8 nodes comprising two PLCs and six I/O units, connected through dual
redundant communication network.
4. 13 to 26 meter rail change over possible through soft logic.
5. A PLC programming station for overall integration of the PLCs communicating with the
remote I/Os.
6. Soft logic to implement control of functional parameters of hardwares and coordinated
operation of different mechanisms for optimal output/productivity of plant.

The present automation system comprises of two PLCs, six Remote I/Os and one PLC
Programming Station. Appropriate interfaces were configured and installed for connection of
all the field signals to the improved PLC based control system. All the 9 nodes are connected
through dual redundant communication network covering a total length of nearly 1.5 Km. The
command signals from the various operation control desks of individual standalone
equipment/facility forwarded to the remote I/O panels installed in the individual pulpits. This
configuration favored substantial reduction/elimination of use of 220Vdc cables, previously
used to connect the control post elements to the hardwired circuits in the machine halls.
It is clearly apparent from the accompanying Figure 1, representing an embodiment of the
automation system according to the invention, that two PLCs such as PLC-1 & PLC-2 ,
installed in M/c Hall no. 2 and M/c Hall no. 3 respectively, wherein three remote I/O units Fi-
ll, R-12 and R-13 are connected with PLC-1. In the same manner, remote I/O units for
operator desk control R-21, R-22 and R-23 are connected with PLC-2 and both PLCs are cable
networked. All the command inputs from the control posts of PP-27 and PP-28 of inspection
stages are connected to R-23. Similarly, the command inputs of PP-23 are connected to R-22
and the inputs of PP-22 to R-21. The command outputs and the feedback signals are
interfaced directly with the main PLCs for majority of the signals. However, for some control
outputs like Dogsink and Stopper are being controlled from their nearest Remote I/Os,
instead of main PLC. The connection scheme as illustrated in accompanying Figure 1,
extends to the mechanisms of Group 1-2 also with command inputs from posts of PP-20 and
PP-26 connected to remote I/O unit R-13, inputs of PP-19 to R-12 and PP-18 to remote I/O
unit R-ll.
The invention further involve configuring appropriate interfaces and install the same
interfacing the 24 Vdc low voltage signals of PLC with the 220Vdc supply based field system
for each individual input and output. The existing control desks were also modified for easy
interface and changeover to the new system.
Operational logic control commands were developed and implemented through PLC
application software for operation of all mechanisms like Transfer beds, Roll Table, Dogsink,
Stopper ,Walking Beam, Rack Pusher, Pneumatic Pusher and Tilter etc. The said operational
logic also incorporated software-based change over of 13m-26m campaigns as well as auto

operation of few mechanisms of the groups to enhance control and operational efficiency of
RSM plant. The implementation of the PLC based automation system replacing the
conventional relay/hardware logic system based control has been carried out in a phased
manner to cause least interruption to the production.
Reference is now invited to the accompanying Figure 2 that illustrates the networking
scheme for the PLCs of the finishing group automation system according to the present
invention using Dual Redundant Communication cable networking. It is evident from the
schematic network of Figure 2 that both the PLCs and six Remote I/Os are connected through
hot redundant communication network cable to take care of the criticality of the controls
involved. Separate cable routes have been chosen carefully to avoid any interference and
simultaneous breakage/failure of communication network cable, enhancing the system
reliability and performance on long term use. The remote I/O nodes Rll, R12 and R 13 are
connected to PLC 1 for operative control on process parameters relating to control desks of
pulpits PP-20/26,PP-19 and PP-18 located in machine hall 2. On the other hand, the remote
I/O nodes R 21, R 22 and R 23 are connected to PLC 2 for operative control on parameters
relating to control desks of pulpits PP-22, PP-23 and PP27/28 in machine hall 3 for operative
auto control on process parameters to achieve finish length of rails of appropriate set-up and
preset logic corresponding to 13m or 26m. Control net protocol with bus speed of 5MBPS was
used for interconnection of remote I/O nodes with the individual PLCs and Ethernet
communication is used for inter-connection of PLCs and the programming unit to keep the
architecture open for up-gradation in future and interface with other systems.
It may further be noted that to ensure effective integration and signal communication for
desired functional automation and process parameter control for RSM finishing groups 1 to 4,
selective Hardware configurations have been used for the PLC panels 1 and 2, and the
respective Remote I/O units communicating with selective numbers of pulpit control desks.
The broad specifications and make of vital hardware elements are presented in Table 1
below:

Table 1:

Some exemplary illustrative embodiment of the present automation system, comprising the
configurations/specification of different hardware elements are as follows:
(A) PLC1:
PLC Panel consisting of:
-Processor SLC 5/05 with 32 KW RAM Cat no. 1747-L552 - 01 no;
-10 Slot I/O chassis Cat no. 1746-A10 -01 no;
-Power supply for CPU Cat no. 1746-P2 -01 no;
-Control Net Scanner Module Cat no. 1747-SCNR15 -01 no;
-32 Ch, 24V DC DI module Cat no. 1746-IB32 - 3 no;
-32 Ch, 24 VDC 0.5 A, DO module Cat no 1746-OB32 - 2 no;
-Front Connectors for modules- 01 set;
-Bus connectors- 01 set; Make AB
-Power supply for Interrogation, 24vdc ,10 A -Olno, Make :Elnova
-Panel Enclosure consisting of : MCBs, Make: Siemens/MDS, Terminals, Make: Elmex,
Isolation Transformer, 240/240 Vac , 1 kva Make: Gupta Engg etc- 01 lot;

(B) Remote I/O Panel Rll (half height) consisting of :
-Flex type redundant control net adapter module, Cat no. 1794-ACNR 15 -01 no
-32 Ch, 24 VDC DI module with terminal base, Cat no 1794-IB32 + 1794 -TB32 - 2 no
-32 Ch, 24 VDC, 0.5 A, DO module with terminal base, Cat no 1794- OB32P + 1794-
TB32 - 1 no
-P.S. (Module + field), 24 VDC , 5A, Make: Elnova
-Panel Enclosure consisting of MCBs, Make: Siemens/MDS, Terminals, Make: Elmex,
Isolation Transformer, 240/240 Vac , 1 kva Make: Gupta Engg etc- 01 lot
(C) Remote I/O Panel R12 (half height) consisting of:
-Flex type redundant control net adapter module, Cat no. 1794-ACNR 15 -01 no
-32 Ch, 24 VDC DI module with terminal base, Cat no 1794-IB32 + 1794 -TB32 - 1 no
-32 Ch, 24 VDC, 0.5 A, DO module with terminal base, Cat no 1794- OB32P + 1794-
TB32 - 1 no
-P.S. (Module + field), 24 VDC , 5A, Make: Elnova
-Panel Enclosure consisting of MCBs, Make: Siemens/MDS, Terminals, Make: Elmex,
Isolation Transformer, 240/240 Vac , 1 kva Make: Gupta Engg etc- 01 lot
(D) Remote I/O Panel R13 (half height) consisting of :
-Flex type redundant control net adapter module, Cat no. 1794-ACNR 15 -01 no
-32 Ch, 24 VDC DI module with terminal base, Cat no 1794-IB32 + 1794 -TB32 - 1 no
-32 Ch, 24 VDC, 0.5 A, DO module with terminal base, Cat no 1794- OB32P + 1794-
TB32 - 1 no
-P.S. (Module + field), 24 VDC , 5A, Make: Elnova
-Panel Enclosure consisting of MCBs, Make: Siemens/MDS, Terminals, Make: Elmex,
Isolation Transformer, 240/240 Vac , 1 kva Make: Gupta Engg etc- 01 lot
(E) PLC 2:
PLC Panel consisting of :
-Processor SLC 5/05 with 32 KW RAM Cat no. 1747-L552 with battery & FEPROM -01 no
-10 Slot I/O chassis Cat no. 1746-A10 -01 no
-Power supply for CPU Cat no. 1746-P2 -01 no
-Control Net Scanner Module Cat no. 1747-SCNR15 -01 no
-32 Ch, 24V DC DI module Cat no. 1746-IB32 - 4 no

-32 Ch, 24 VDC 0.5 A, DO module Cat no 1746-OB32 - 3 no
-Front Connectors for modules- 01 set
-Bus connectors- 01 set; Make AB
-Power supply for Interrogation, 24vdc ,10 A -Olno, Make :Elnova
-Panel Enclosure consisting of MCBs, Make: Siemens/MDS, Terminals, Make: Elmex,
Isolation Transformer, 240/240 Vac , 1 kva Make: Gupta Engg etc- 01 lot;
(F) Remote I/O Panel R21 (half height) consisting of :
-Flex type redundant control net adapter module, Cat no. 1794-ACNR 15 -01 no;
-32 Ch, 24 VDC DI module with terminal base, Cat no 1794-IB32 + 1794 -TB32 - 1 no;
-32 Ch, 24 VDC, 0.5 A, DO module with terminal base, Cat no 1794- OB32P + 1794-
TB32 - 1 no;
-P.S. (Module + field), 24 VDC , 5A, Make: Elnova;
-Panel Enclosure consisting of MCBs, Make: Siemens/MDS, Terminals, Make: Elmex,
Isolation Transformer, 240/240 Vac , 1 kva Make: Gupta Engg etc- 01 lot;
(G) Remote I/O Panel R22 (half height) consisting of :
-Flex type redundant control net adapter module, Cat no. 1794-ACNR 15 -01 no;
-32 Ch, 24 VDC DI module with terminal base, Cat no 1794-IB32 + 1794 -TB32-2 no;
-32 Ch, 24 VDC, 0.5 A, DO module with terminal base, Cat no 1794- OB32P + 1794-
TB32 - 2 no;
-P.S. (Module + field), 24 VDC , 5A, Make: Elnova
-Panel Enclosure consisting of MCBs, Make: Siemens/MDS, Terminals, Make: Elmex,
Isolation Transformer, 240/240 Vac , 1 kva Make: Gupta Engg etc- 01 lot;
(H) Remote I/O Panel R23 (half height) consisting of :
-Flex type redundant control net adapter module, Cat no. 1794-ACNR 15 -01 no
-32 Ch, 24 VDC DI module with terminal base, Cat no 1794-IB32 + 1794 -TB32 - 1 no
-32 Ch, 24 VDC, 0.5 A, DO module with terminal base, Cat no 1794- OB32P + 1794-
TB32 - 1 no
-P.S. (Module + field), 24 VDC , 5A, Make: Elnova

-Panel Enclosure consisting of MCBs, Make: Siemens/MDS, Terminals, Make: Elmex,
Isolation Transformer, 240/240 Vac , 1 kva Make: Gupta Engg etc- 01 lot;
(I) Network accessories for 10 nodes such as connectors, terminators, repeaters, switches,
accessories for hot stand by communication etc;
(J) Network cable
-Coaxial communication cable - 1200 meters;
-CAT6 Ethernet Communication cable- 300 meters;
Cable to have adequate mechanical strength.
(K) Cabling & conduiting for communication network-1500Mtrs.
(Laying is done without any joints between two ports)
(L) PC with communication network adapter-1 No;
(M) Portable PLC programmer with communication network adapter-lNo.;
Erection And Commissioning Of Harwares And Network Of Cables:
The programmable logic controllers PLC-1 and PLC-2 are installed in M/c Hall No-2 and M/c
Hall No-3 respectively. Further, the three remote I/Os R-21, R-22 and R-23 for Groups 3-4,
are connected with PLC-2 and networked. Similarly, Remote I/Os R-ll, R-12 and R-13 for
Groups 1 and 2, are connected with PLC-1 and also networked with common bus cable route
covering all four groups. All the field inputs of PP-27 and PP-28 are connected to R-23.
Similarly, field inputs of PP-23 are connected to R-22 and inputs of PP-22 to R-21. Similarly,
field inputs of PP-20 & PP-26 are connected to R-13, inputs of PP-19 to R-12 & PP-18 to R-13.
To connect field I/Os for capturing input/output data, standard signal cables has been used
from control panel to nearest PLCs and Remote I/O panel. About 2000 metres of standard
signal cables were used for termination of field I/Os to the system. All the cables have been
embedded in Steel GI pipe conduits for protection.
The existing equipment earth of the shop was used for panel earth. Separate earth pits are
made for PLCs and Remote I/Os. The electronic earth has been distributed from a single

source to all the nodes along with communication cable to avoid any mismatch in earth
potential.
The complete commissioning of the system has been done in-house. Complete I/O listing
including termination details has been prepared for more than 800 I/O signals. Total
commissioning is carried out in different phases with minimum interruption of the
mainstream production.
Software Development:
For full reliable functioning of hardware devices of the PLC based automation and control
system according to the present invention for the RSM plants, PLC application programs have
been developed. The programs are developed in a modular manner. Separate modules have
been written for individual Roll Tables, Transfer Beds, and Chain Transfer etc. Precaution has
been taken for all the inter locks for the operation of Walking Beam, Rack Pusher, Pneumatic
Pusher. Software includes all algorithms for operation of the mechanisms for 13m as well as
26 m processing and easy change-over between the campaigns as well as automatic
operations of few of the mechanisms of the groups.
Field Trials and Observed results:
To evaluate the efficiency and reliability of the PLC based automation and control system of
the present invention extensive trials were carried out without load and also with load before
putting the system on-line. To ensure trouble free operation and control of various
mechanism involved in the RSM finishing groups, particularly where interlocks are used,
required lot of trials. Some small changes/adjustments in the position of rotary limit switches
conducted to make them match perfectly with the new soft logic.
The integrated network based centralized automation system for Finishing Groups has been
successfully achieved in plant by introducing the principles as discussed above, for all the
mechanisms involved in Groups 1 through Group 4, and also for the corresponding feed-in
and inspection zones. The new PLC based system not only proved to be more reliable but also
adapted to simple and faster troubleshooting/diagnosis of any possible electrical fault, either
in the PLC system or in any field mechanisms. Since the conventional hard-wired logics have
been replaced by soft logic, the maintenance time has been reduced drastically. More
advantageously, any modification in the control algorithm to accommodate process variables

is easily and flexibly achievable. All these features enable reduction in electrical downtime
and facilitate central supervision and control of finishing area.
It is thus possible by way of the present invention directed to PLC based automation and
control system for RSM finishing groups wherein a network based system is successfully
implemented for critical control of operating parameters of equipments and processes by way
of a robust design configuration of all intervening hardwares, panels, PLCs, PC/processors
and their interfacing soft logic wherein all safety interlocks has been exhaustively considered
to improve quality and productivity of finishing plants of rail and structural mills. The system
has further yielded added benefit in terms of elimination of all control cables from various
Control Pulpits to Electrical Control Panels located at M/c Halls. Importantly also, the PLC
based automation system is adapted to easy implementation of future expansion and
modification, apart from cost-effective and fast changeover from 13m to 26m rails and vice
versa with enough flexibility. Also the system provides a backbone for future Automation. The
present automation system is capable of continued operation through online controls and
feedback monitoring based on the network connecting vital nodes reliably even in high
speeds of operation, making such system suitable for wide industrial applications with
economic advantage.

We Claim:
1. A system for controlling and monitoring finishing groups of Rail and Structural Mills
(RSM) comprising
(i) programmable logic controllers (PLC) based centralized control and monitoring
for ease of maintenance & reducing downtime.
(ii) remote I/O stations at distributed locations for inputting and outputting various
control parameters.
(iii) plurality of nodes connected through dual redundant communication network;
and
(iv) means adapted for 13 to 26 meter rail change over through soft logic in place of
hard wired control circuit.
2. A system for controlling and monitoring finishing groups of Rail and Structural Mills (RSM)
as claimed in claim 1 comprising a network connecting plurality of nodes for control of
facilities in multiple machine halls of RSM, comprising of PLCs, Remote I/O and a PLC
programming station for operative control on mechanisms/functions of various finishing
groups in different machine halls which are distanced from one another;
said network being an integrated dual redundant communication network connecting the
selective numbers of communicating nodes;
means to interface with soft logic for operative control and change over of rail length from
13 m to 26 m and vice versa, as and when required;
said network adapted for signal exchange to select and implement desired process
parameters between respective nodes through programmed logic control means adapted to
generate commands, enabling easy and fast fault diagnosis and repair.
3. A system for controlling and monitoring finishing groups of Rail and Structural Mills (RSM)
as claimed in anyone of claims 1 or 2 comprising
a network connecting nine nodes for control of facilities in two machine halls of RSM,
comprising two PLCs, six Remote I/O panels and one PLC programming station for

operative control on mechanisms/functions of finishing Group 1 to Group 4 in different
machine halls at large distance apart;
said network being an integrated dual redundant communication network connecting
the specified number of communicating nodes;
said system adapted to be interfaced with soft logic for operative control and change
over of rail length from 13 m to 26 m and vice versa, as and when needed;
said network adapted to signal exchange to select and implement desired process
parameters between respective nodes through soft logic generated commands,
enabling easy and fast fault diagnosis and repair.
4. A system for controlling and monitoring finishing groups of Rail and Structural Mills (RSM)
as claimed in claim 3 wherein one of the two PLCs (such as PLC 1) wherein one said PLC is
connected to three remote I/O units in one machine hall and another PLC is connected to
another set of three remote I/O units in a separate machine hall having panels near the
operator's control desk at the pulpits and are networked.
5. A system for controlling and monitoring finishing groups of Rail and Structural Mills (RSM)
as claimed in anyone of claims 3 or 4, wherein one said PLC extends control to the
mechanisms/processes of two Groups in a machine hall, with command inputs from plurality
of posts connected to remote I/O unit, including those of inspection stages.
6. A system for controlling and monitoring finishing groups of Rail and Structural Mills (RSM)
as claimed in claim 5 wherein another said PLC extends control to the mechanisms/processes
of another two groups in another machine hall, with all command inputs from the
operatively connected control posts including those of inspection stages and respective
remote I/O units .
7. A system for controlling and monitoring finishing groups of Rail and Structural Mills (RSM)
as claimed in anyone of claims 1 to 6 wherein said network comprises interfacing the 24 Vdc
low voltage signals of PLC with the 220Vdc supply based field system for each individual input
and output.

8. A system for controlling and monitoring finishing groups of Rail and Structural Mills (RSM)
as claimed in anyone of claims 1 to 7 wherein, said programmed logic control commands are
adapted for development and implementation through PLC application software for operation
of all mechanisms like Transfer beds, Roll Table, Dogsink ,Stopper , Walking Beam, Rack
Pusher, Pneumatic Pusher &Tilter.
9. A system for controlling and monitoring finishing groups of Rail and Structural Mills (RSM)
as claimed in anyone of claims 1 to 8 wherein control outputs such as Dogsink and Stopper
are operatively controlled from their nearest Remote I/Os, instead of main PLC.

10. A system for controlling and monitoring finishing groups of Rail and Structural Mills
(RSM) as claimed in anyone of claims 1 to 9 wherein signal exchange between the respective
nodes and the PLC in a Group are carried out through said dual redundant communication
network wherein separate cable routes chosen carefully to avoid any interference and/or
simultaneous breakage/failure of communication network cable, ensuring enhanced
reliability.
11. A system for controlling and monitoring finishing groups of Rail and Structural Mills
(RSM) as claimed in anyone of claims 1 to 10 wherein said dual redundant communication
network are adapted to eliminate use of control cables from control pulpits to machine halls.
12. A system for controlling and monitoring finishing groups of Rail and Structural Mills
(RSM) as claimed in anyone of claims 1 to 11 comprising control net protocol with desired
bus speed for interconnection of remote I/O nodes with respective individual PLCs and
Ethernet communication for inter-connection of PLCs and the programming unit to keep the
architecture open for up-gradation in future and also interfacing with other systems .
13.A system for controlling and monitoring finishing groups of Rail and Structural Mills (RSM)
as claimed in anyone of claims 1 to 12 wherein, selective hardware configurations are
provided for the PLC panels, and the respective Remote I/O units communicating with
selective numbers of corresponding pulpit control desks to ensure effective integration and
signal communication for desired functional automation and control of process parameters for
RSM finishing groups connected in said dual redundant communication network.
14. A system for controlling and monitoring finishing groups of Rail and Structural Mills
(RSM) as claimed in anyone of claims 1 to 13 wherein said dual redundant communication

A system for controlling and monitoring mechanisms of finishing groups in Rail and Structural
Mills(RSM). More particularly, it is a PLC based system of nine different nodes comprising two
PLCs and six remote I/O nodes and one PLC programming station covering mechanisms in
four separate groups in two machine halls connected through through a Dual Redundant
Communication Network covering a stretch of nearly 1.5 Km. The system integrates and
coordinates functions relating to 109 mechanisms that include Walking Beam, Rack Pusher,
Pneumatic Pusher, Tilter and Roll table, involving 415 inputs and 325 outputs from control
pulpits connected to the remote I/O units connected to PLCs. The system interfaced with
application software sends/receives/process commands/signals for desired control.
Importantly, a soft logic based change over from 13m and 26m rails and vice versa is
implemented as needed, at least time and cost. The system thus favor easy detection of
faults , reduce down time for maintenance, making wide application of such automation and
control system for finishing group mechanisms for RSM or similar other plants with significant
economic advantages.