Specifications

Gaia
GAIA.ASU.SP.ESM.00007
Issue 2.00
Page 30 of 79
Astrium Ltd owns the copyright of this document which is supplied in confidence and which shall not be used for any purpose other than that for which it is supplied and shall not in
whole or in part be reproduced, copied, or communicated to any person without written permission from the owner.
GAIA.ASU.SP.ESM.00007 (Avionics SCOE Req Iss 2).doc
3.6.4 PacketWire BUS Interfaces
AVI-3476/CDMU-3941/T
Interfaces shall be provided for the Spacecraft CDMU/PDHU (4) PacketWire (PW) BUS.
AVI-3477/GSE-SYS-397/T
Each Interface shall provide the following services:
Redundant Bus Operation (A/B)
Bus Monitor Functions (Bus Spy)
AVI-3483/CDMU-3943/T
The PW Interface signalling rate shall operate to a maximum of 10 Mbps.
AVI-3530/CDMU-3449/T
The PW Interface shall withstand a data throughput from the PLM of 2000 packets/second with a
packet size varying from 300 bytes to 32 Kbytes.
AVI-3531/CDMU-3947/T,R
The PW Interface shall be implemented in accordance with the requirements of AD08.
AVI-3485/CREATED/T
The PW BUS Interface cards shall be configured and controlled by the Avionics SCOE, or by direct
interface to the RTS for closed-loop Avionics testing.
AVI-3486/CREATED/R
The PW BUS Interface cards shall be based on COTS or previously developed in-house systems
(where possible).
AVI-3488/CREATED/T
The Avionics SCOE shall provide decommutation of the PW BUS data for parameter acquisition of
each BUS.
AVI-3489/CREATED/T
For each PW BUS, Prime and Redundant BUS operation shall be possible in parallel.
AVI-3490/CREATED/T
The Avionics SCOE shall provide data simulation for each PW BUS.
AVI-3491/CREATED/T
It shall be possible to configure PW BUS operation from the local MMI, by definition from the CCS
(Test Procedure/Command Line) or from the RTS.
AVI-3492/CREATED/T
The following configuration options shall be available for each PW BUS:
Command: Comment
INITIALISE Reset, Disabled, Spy OFF
DISABLE Disabled, Spy OFF
ENABLE Enabled, Spy OFF
ENABLE SPY Spy ON (BUS may be disabled)
DISABLE SPY Spy OFF
ENABLE PASSIVE
3
Enabled, but does not respond on the BUS
DISABLE PASSIVE
3
Disabled
SET ERROR n Set specified ERROR on SpaceWire BUS