®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 1
Improvements in SpaceWire Test
Paul Walker, Barry Cook
4Links Limited
www.4Links.co.uk
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 2
Content
Why record test results?
Why time-tag the recordings?
Resolving anomalies
Scalable recording
Monitoring Time Codes
Generating low-jitter Time Codes
RMAP Responder
Integrating all of these together
A real-life example for BepiColombo:
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 3
Why record test results?
In Assembly, Integration and Validation (AIV/AIT) of satellites and their subsystems, you need to record the tests:
to resolve anomaliesto archive successful results as a reference
With a bus such as MIL 1553, a bus spy is fine
With SpaceWire, it is not so easy
4Links offer a solution
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 4
Recording SpaceWire
Gbit Ethernet connection to PC with disc(s)
Any SpW Unit
Any SpW Unit
Any SpW Unit
Any SpW Unit
Any SpW Unit
Any SpW Unit
Multilink SpaceWire Recorder
Multi-link SpaceWire Recorder records up to four links
Records both directions of each link
Computer and disc(s) need to be fast and dedicated
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 5
Why time-tag the records?
With 1553, traffic is purely sequential, but is time-tagged anyway.
SpaceWire has lots of concurent communications, so time tagging the records is even more important
With SpaceWire-RT, there is even more need to know when events occur in the network
Recordings are analyzed off-line to produce readable logs, for example:
10.079 194 952 0s 1<--2 Data @0000 05 55 30 1<--2 EOP at 10.079 195 552 0s (SOP + 0.600us) 10.079 195 792 0s 1<--2 Data @0000 05 55 30 1<--2 EOP at 10.079 196 392 0s (SOP + 0.600us)
Time-tag Direction Data
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Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 6
Resolving anomalies
Pairs of packets should be arriving at 10ms intervals
Third packet arrives immediately after first pair, too early
Fourth packet arrives 20ms later, too late
10.480 772 121 4s 1<--2 Data @0000 05 55 32 1<--2 EOP at 10.479 772 721 4s (SOP + 0.600us) 10.480 772 961 4s 1<--2 Data @0000 05 55 37 1<--2 EOP at 10.479 773 561 4s (SOP + 0.600us) 10.480 773 800 0s 1<--2 Data @0000 05 55 70 1<--2 EOP at 10.479 774 401 4s (SOP + 0.601us) 10.680 351 792 0s 1<--2 Data @0000 05 55 73 1<--2 EOP at 10.680 352 392 0s (SOP + 0.600us)
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Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 7
Scalable recording
Multilink SpaceWire Recorder
Multilink SpaceWire Recorder
Multilink SpaceWire Recorder
Multilink SpaceWire Recorder
Recorders need to be synchronized to preserve time relationship
Just connect the sync daisy chain and they synchronize
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 8
Adding datation
IRIG Time of Year reference
Multi-link SpaceWire Recorder
Absolute Time Interface
The recorder is sychronized to an absolute reference clock, such as GPS, Loran, or the on-board clock
Synchronization is via the IRIG standard
IRIG references are available in rack units or boards
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Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 9
Dated time-tagged records
Day:hh:mm:ss ms us ns Flow Activity288:15:25:10.263 728 870 1s 1<--2 Data @0000 01 02 03 04 05 06 07 08 1<--2 Data @0008 09 0A 0B 0C 0D 0E 0F 10 1<--2 Data @0010 11 12 13 14 15 16 17 18 1<--2 Data @0018 19 1A 1B 1C 1D 1E 1F 20 1<--2 Data @0020 21 22 23 24 25 26 27 28 1<--2 Data @0028 29 2A 2B 2C 2D 2E 2F 30 1<--2 Data @0030 31 32 1<--2 EOP at 288:15:25:10.263 731 370 1s (SOP+2.500us)288:15:25:15.249 072 811 5s 1<--2 Data @0000 01 02 03 04 05 06 07 08 1<--2 Data @0008 09 0A 0B 0C 0D 0E 0F 10 1<--2 Data @0010 11 12 13 14 15 16 17 18 1<--2 Data @0018 19 1A 1B 1C 1D 1E 1F 20 1<--2 Data @0020 21 22 23 24 25 26 27 28 1<--2 Data @0028 29 2A 2B 2C 2D 2E 2F 30 1<--2 Data @0030 31 32 1<--2 EOP at 288:15:25:15.249 075 311 5s (SOP+2.500us)
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Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 10
Scalable datation
IRIG Time of Year reference
Multilink SpaceWire Recorder
Multilink SpaceWire Recorder
Multilink SpaceWire Recorder
Multilink SpaceWire Recorder
Absolute Time Interface
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 11
Integrating Time Codes
The Absolute Time Interface has a SpaceWire port
Used to generate low jitter Time Codes
Default is 1pps Time Code
Optionally four Time Codes, as NASA/JWST, with settable intervals
All aligned to IRIG (hence to GPS or on-board clock)
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Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 12
Datation on Time Codes
Time Codes are aligned to IRIG to within nanoseconds
Recordings can include mix of Time Codes and packets
Day:hh:mm:ss ms us ns Flow Activity288:15:19:31.000 000 000 5s 1-->2 Time Code 00288:15:19:32.000 000 000 5s 1-->2 Time Code 01288:15:19:33.000 000 000 5s 1-->2 Time Code 02288:15:19:34.000 000 000 5s 1-->2 Time Code 03288:15:19:35.000 000 000 5s 1-->2 Time Code 04288:15:19:36.000 000 000 5s 1-->2 Time Code 05288:15:19:37.000 000 000 5s 1-->2 Time Code 06288:15:19:38.000 000 000 5s 1-->2 Time Code 07288:15:19:38.869 933 928 8s 1<--2 Data @0000 01 02 03 04 05 06 07 08 1<--2 Data @0008 09 0A 0B 0C 0D 0E 0F 10 1<--2 Data @0010 11 12 13 14 15 16 17 18 1<--2 Data @0018 19 1A 1B 1C 1D 1E 1F 20 1<--2 Data @0020 21 22 23 24 25 26 27 28 1<--2 Data @0028 29 2A 2B 2C 2D 2E 2F 30 1<--2 Data @0030 31 32 1<--2 EOP at 288:15:19:38.869 936 428 8s (SOP+2.500us)288:15:19:39.000 000 000 5s 1-->2 Time Code 08288:15:19:40.000 000 000 5s 1-->2 Time Code 09
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Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 13
12 hour Jitter accumulation
200ns/div
IRIG Reference edge
SpaceWire S signal, showing:
ESCDataStart of Null
Start of Time Code is aligned with IRIG
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Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 14
8 hour Jitter accumulation
20ns/div
IRIG Reference edge
Leading edge of Time Code
Approx 30ns jitter in eight hours
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 15
RMAP responder
RMAP needs support from test equipment
New RMAP resonder provides local memory for RMAP, managed by a computer
Provides ideal combination of low-latency responseconsistent access to the RMAP memoryfull control of RMAP memory by user
Existing product can be upgraded by replacing the plug-in memory card
Test functions appropriate for any stage of project
Diagnostic SpaceWire Interface DSI-RG408Diagnostic SpaceWire Interface DSI-RG408
Memory Card
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 16
Integrating a test system
IRIG Time of Year reference
Multilink SpaceWire Recorder
SpaceWire Packet Generator
Diagnostic SpaceWire Interface
RMAP Responder
Absolute Time Interface
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 17
Diagnostic SpaceWire Interface DSI-RG408
Diagnostic SpaceWire Interface DSI-RG408
Test set for BepiColumbo
OBC
IRIG Reference
SpaceWire
Ethernet
Reference
Sync daisy-chain
RMAP Responer
Multilink SpaceWire Recorder
Absolute Time Interface
®4Links
Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 18
Recording SpaceWire packets is a necessary part of system verification
For detecting and resolving anomaliesFor archiving evidence clean runs
Records need to be time taggedTime tags often need to be dated
4Links provides the solutions, for any size of system, often with boxes you already have
Test functions appropriate for any stage of project
Diagnostic SpaceWire Interface DSI-RG408Diagnostic SpaceWire Interface DSI-RG408
Conclusions