FIELD OF THE INVENTION
This invention relates to Control and Indication Unit (CIU) for Solid State Flight Data Recorder
(SSFDR) and, more particularly, for indication of health of SSFDR.
BACKGROUND OF THE INVENTION
Solid State Flight Data Recorder (SSFDR) used in aircraft to acquire data from cockpit voice,
analog inputs, thermocouples, RTD’s, Tacho, discrete inputs, MIL1553B bus & ARINC 429
channels from Aircraft. The acquired data is stored in Flash memory. The stored parameters in
FLASH memory are milked out through Ethernet 10/100 port. These parameters are used for
post flight & engine run analysis and Crash analysis.
The system comprises of 3 LRU’s viz. Data Acquisition Unit (DAU), Recorder Unit (RU) &
Control and Indication Unit (CIU). Data recorded in both DAU & RU.
The Data Acquisition Unit (DAU), the main LRU in the system. It acquires data from cockpit
voice, analog inputs, thermocouples, RTD’s, Tacho, discrete inputs, MIL1553B bus & ARINC
429 channels. The acquired data is stored in Flash memory in DAU and the selected
parameters are sent to Recorder Unit (RU) through ARINC 717 interface. The stored
parameters in DAU flash memory are milked out through Ethernet 10/100 port. These
parameters are used for post flight & engine run analysis.
SUMMARY OF PRESENT INVENTION
CIU is a passive unit and one of the main LRU in SSFDR. This unit provides junction between
DAU, RU & external milking units and it is basically for fault indication of the DAU and RU.
External milking units download data from DAU or RU through this unit. It also indicates the
health of both DAU & RU through LED’s.
This LRU acts as Maintenance Panel. It is situated in the avionics bay and forms the main
interface between the maintenance crew and the FDR.
It is called Control & Indication Unit because it controls the recording in both DAU & RU. Along
with this it indicates the status of recording in both DAU & RU.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention become more apparent and
descriptive in the description when considered together with figures/flow charts presented:
Figure 1: is a Block Diagram of SSFDR System
Figure 2: is a Block Diagram of Control and Indication Unit (CIU)
DETAILED DESCRIPTION
CIU is a passive unit and one of the main LRU in SSFDR. This unit provides junction
between DAU, RU & external milking units and it is basically for fault indication of the DAU and
RU. External milking units download data from DAU or RU through this unit. It also indicates
the health of both DAU & RU through LED’s.
This LRU acts as Maintenance Panel. It is situated in the avionics bay and forms the
main interface between the maintenance crew and the FDR.
It is called Control & Indication Unit because it controls the recording in both DAU & RU.
Along with this it indicates the status of recording in both DAU & RU.
Front panel of CIU consists of Status indication lights, Test button for status indicators,
the start/stop recording switch, downloading interface connector & power circuit breaker.
Rear panel consists of connector & Identification label. The architecture of the CIU is
shown in the Figure: 2.
STATUS INDICATORS:
The CIU display FDR status information as follows:
RU Fault Status
The FAULT_CRD_O (RU crash data failure status) and FAULT_CVR_O (RU cockpit
voice recorder failure status) are displayed with red indicators. The active state is +27V.
DAU Fault Status:
The FAULT_DAU1_O (Indicates that the error exist in signal flow path to the DAU flash
disk) and FAULT_DAU2_O (Indicates that the error exist in signal flow path to the RU) fault
statuses are displayed with red indicators. The active state is +27V.
DAU recorder Status:
The RECORDING_INDICATOR_O status displayed with a green indicates that indicates
the DAU is in the recording mode. The active state is +27V.
CONTROL INPUTS:
The CIU provide two functional inputs, the Stop/ Start Recording input and Ground
Power Relay input, and in addition a test input to test the indicator lights.
I. Start/Stop Recording Input:
The Stop / Start Recording input allows selection between automatic mode (the Ground
Power Relay input determines transition to and from recording mode) and ON mode (the DAU is
commanded into recording mode). Either of these inputs can switch the DAU in to ON mode,
both of them must be in the AUTO position to switch the DAU into OFF mode.
II. Lamp Test:
The lamp test input by means of a push-to- test switch that causes all of the status
indicators to be lit.
ETHERNET POLARITY:
The CIU provides crossover of the transmit (TX) and Receive (RX) Ethernet lines. On
the aircraft side (that is on J2), TX refers to transmission from the DAU and RU; while on ground
Station Side (J1) TX refers to transmission from the ground Station, Either DDRU or RDRU.
CIU Power:
The CIU is powered from the 27VDC DDRU power output from the DAU. The power
consumed by the CIU considered as DAU power consumption (i.e. the sum of the actual DAU
and CIU power not exceed the maximum DAU power requirement).
The CIU provides current overload, circuit breaker protection only for the power it
transfers to the DDRU. Current overload protection devices in the DAU and RU protect the
internal CIU power consumption.
The DAU provides power for the CIU LED’s, RU recording control relay solenoid and
ground power relay solenoid.
Unit Connectors
The CIU is equipped with two circular type connectors, compliant with MIL-C-38999, one
on the front panel (J1) and one on the back panel (J2). The front panel accepts a loom from
either the DDRU or RDRU (these are not connected simultaneously). The back panel
connector, of opposite gender to the front panel connector, accepts a loom from the FDR.

WE CLAIMS:-
Accordingly, the description of the present invention is to be considered as illustrative only and is for the purpose of teaching those skilled in the art of the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and exclusive use of all modifications which are within the scope of the appended claims is reserved. The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Control and Indication Unit (CIU) Comprising; Controls the recording in both DAU & RU & indicates the status of recording in both DAU & RU. CIU also indicates the health of both DAU & RU through LED’s; The CIU provides crossover of the transmit (TX) and Receive (RX) Ethernet lines for downloading of data from SSFDR.

2. Control and Indication Unit (CIU) of claim 1 wherein unit acts as Maintenance Panel. It is situated in the avionics bay and forms the main interface between the maintenance crew and the FDR.

3. Control and Indication Unit (CIU) of claim 1 wherein Front panel of CIU consists of Status indication lights, Test button for status indicators, the start/stop recording switch, downloading interface connector & power circuit breaker.

4. Control and Indication Unit (CIU) of claim 1 wherein Rear panel consists of connector & Identification label.

5. Control and Indication Unit (CIU) of claim 3 wherein The CIU displays FDR status information as DAU fault status, RU fault status, DAU recording status & RU recording status.

6. Control and Indication Unit (CIU) of claim 1 wherein the CIU provides two functional inputs, the Stop/ Start Recording input and Ground Power Relay input, and in addition a test input to test the indicator lights.

7. Control and Indication Unit (CIU) as claimed in any of the proceedings claim the CIU provides current overload, circuit breaker protection only for the power it transfers to the DAU data retrieval unit (DDRU). Current overload protection devices in the DAU and RU protect the internal CIU power consumption.
,TagSPECI:As per Annexure-II