Specifications

Gaia
GAIA.ASU.SP.ESM.00007
Issue 2.00
Page 39 of 79
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GAIA.ASU.SP.ESM.00007 (Avionics SCOE Req Iss 2).doc
3.6.6.3 MPS FCV Command Pulse Acquisition
AVI-3579/GSE-SYS-740/T
The MPS FCV Command Pulse Acquisition interface shall be provided by fixed loads (16x) simulating
each of the FCV coils.
AVI-3580/GSE-SYS-740/T
The FCV Command Acquisition interface shall conform to the following specifications: [AD06] Table
3.5-36 (Flow Control Valve Interface Specification - Receiver Circuit Specification).
AVI-3581/GSE-SYS-740/T
FCV Command Pulse Acquisition shall provide measurements of the integrated ON time for each
FCV, the individual command pulse widths and an event count per FCV, as detailed below:
EVENT COUNT limit 65536
ON time resolution 5 %
Pulse WIDTH resolution
100.0 µs - for pulse widths 5ms to continuous
Table 3.6-5: CPS - FCV Command Pulse Measurement Specification
AVI-3593/CREATED/T
Once an FCV Command has triggered, ON time measurements shall be integrated every 15.625 ms
(equivalent to the RTS Simulation Cycle rate of 1/64 of the Major Frame rate) and calculated as
percentage (ON) over the integration period. TBC
Note: Although the CPS Model in the RTS executes at 64Hz in real-time, thrust vectors output to the
Dynamics Model need to consider thruster pulses to an accuracy of <1ms.
AVI-3595/CREATED/T
Measurement of LV Command pulses shall be triggered asynchronously by detection of an incoming
pulse with the following specifications:
• Pulse Width > 1ms
• Pulse Amplitude > 10.0V
AVI-3596/CREATED/T
It shall be possible to reset the event counters, individually or all at once, by command from the local
MMI or from the CCS (Test Procedure/Command Line)..
AVI-3597/GSE-SYS-740/T
FCV ON times shall be made available to the RTS for closed-loop testing.
AVI-3598/GSE-SYS-756/T
It shall be possible to acquire the FCV pulses simultaneously on all channels.