1. 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

2. 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:

3. 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 anomalies to 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

4. Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 4 Recording SpaceWire 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

5. 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

6. 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)

7. Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 7 Scalable recording Multilink SpaceWire Recorder Recorders need to be synchronized to preserve time relationship Just connect the sync daisy chain and they synchronize

8. Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 8 Adding datation 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

9. 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 Activity 288:15:25:10.263 728 870 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)

10. 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 Absolute Time Interface

11. 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)

12. 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 Activity 288:15:19:31.000 000 000 5s 1-->2 Time Code 00 288:15:19:32.000 000 000 5s 1-->2 Time Code 01 288:15:19:33.000 000 000 5s 1-->2 Time Code 02 288:15:19:34.000 000 000 5s 1-->2 Time Code 03 288:15:19:35.000 000 000 5s 1-->2 Time Code 04 288:15:19:36.000 000 000 5s 1-->2 Time Code 05 288:15:19:37.000 000 000 5s 1-->2 Time Code 06 288:15:19:38.000 000 000 5s 1-->2 Time Code 07 288:15:19:38.869 933 928 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 08 288:15:19:40.000 000 000 5s 1-->2 Time Code 09

13. 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: ESC Data Start of Null Start of Time Code is aligned with IRIG

14. 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

15. 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 response consistent access to the RMAP memory full 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-RG408 Memory Card

16. 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

17. Imrovements in SpaceWire Test: International SpaceWire Conference, Nara, Japan, 2008-11-6, Paul Walker, Barry Cook, 4Links 17 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

18. 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 anomalies For archiving evidence clean runs Records need to be time tagged Time 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-RG408 Conclusions