4Links Diagnostic SpaceWire Interface User manual

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User Manual for the
4Links
Diagnostic SpaceWire Interface
Version 5

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Revision History
Version
Date
Notes
5
February 2019
General update and removal of C-API into a separate document.
4
September 2013
Substantial additions, including incorporation of the C-language
programming API details, new CO, OE and OD options, and use of new
text processing tools.
3
April 2010
Added: RG8R platform, Platform data, Usage information.
2
June 2007
Added: Multi-unit synchronisation, Delta Time-Tags,Packet
Generator / Checker.
1
November 2006
Initial version.
Legal notice and disclaimer: Copyright 2018 4Links Limited, all rights reserved. The name 4Links and the accompanying device are registered as a
Trademark in the European Union and in the United States of America. The name SpaceWire was originated by the European Space Agency whose rights are
acknowledged, and 4Links makes no claim to the word SpaceWire being a 4Links trademark. The information supplied in this document is believed to be
accurate at the date of issue. 4Links reserves the right to change specifications or to discontinue products without notice. 4Links assumes no liability arising
out of the application or use of any information or product, nor does it convey any licence under its patent rights or the rights of others. Products from 4Links
Limited are not designed, intended, authorised or warranted to be suitable for use in
life-support devices or systems. 4Links Limited is registered in England and Wales, with Company Number 3938960. Issued 2nd February 2018
2019 4Links Limited

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Contents
Revision History........................................................................................................................................................2
1 Introduction .........................................................................................................................................................6
1.1 Product Features ..........................................................................................................................................6
1.2 Product Options............................................................................................................................................6
2 Operation.............................................................................................................................................................7
2.1 General .........................................................................................................................................................7
2.2 Getting Started .............................................................................................................................................8
2.3 Standard Diagnostic SpaceWire Interface Capabilities ................................................................................8
2.4 DSI Options ...................................................................................................................................................9
2.4.1 ER - Event / Error Reporting .................................................................................................................9
2.4.2 EW- Event / Error Waveforms ..............................................................................................................9
2.4.3 EI - Event / Error Injection ....................................................................................................................9
2.4.4 TT - Time-tags .................................................................................................................................... 10
2.4.5 SO - Synchronized Outputs................................................................................................................ 10
2.4.6 CO - Controlled Outputs .................................................................................................................... 10
2.4.7 OD and OE - Output Disable and Output Enable............................................................................... 10
2.5 Front-Panel Display.....................................................................................................................................11
2.5.1 Ethernet Information......................................................................................................................... 11
2.5.2 SpaceWire Information...................................................................................................................... 11
2.5.3 Communication Protocol................................................................................................................... 11
2.6 Programming API........................................................................................................................................12
3 Specification...................................................................................................................................................... 13
3.1 SpaceWire Links..........................................................................................................................................13
3.1.1 SpaceWire Receive Performance....................................................................................................... 13
3.1.2 SpaceWire Transmit Performance..................................................................................................... 13
3.1.3 SpaceWire Connectors ...................................................................................................................... 13
3.1.4 SpaceWire Time Codes ...................................................................................................................... 14
3.2 The Ethernet Connection............................................................................................................................14
3.2.1 ICMP Echo (ping) Support.................................................................................................................. 14
3.2.2 Full-Duplex Ethernet.......................................................................................................................... 14

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3.3 SMA Synchronisation Connectors ..............................................................................................................14
3.4 Discovering a Unit’s Serial Number and Installed Product Options ...........................................................15
3.4.1 The Unit Serial Number and its relation to the Ethernet MAC address............................................ 15
3.4.2 Installed Product Options.................................................................................................................. 15
3.5. The RG408 Hardware Platform .......................................................................................................................15
3.4.3 Handling and Transportation............................................................................................................. 16
3.4.4 RG Platform Firmware ....................................................................................................................... 16
4 Block Diagram ................................................................................................................................................... 17
5 User Interface ................................................................................................................................................... 17
5.1 Initial (Power-up) display............................................................................................................................17
5.2 Normal (Status) display ..............................................................................................................................18
6 Front Panel Interaction..................................................................................................................................... 20
6.1 IP address....................................................................................................................................................22
6.2 Time Synchronisation .................................................................................................................................23
6.3 Health Display.............................................................................................................................................23
7 DSI Option Details............................................................................................................................................. 25
8 Option ER –Event/Error Reporting................................................................................................................... 25
9 Option TT –Time Tags ...................................................................................................................................... 25
10 Option EI –Event/Error Injection...................................................................................................................... 26
11 Option EW –Event/Error Waveforms............................................................................................................. 27
11.1.1 SpWIO Event Waveform Defaults.................................................................................................... 30
11.1.2 SpWIO Event Waveform Examples ................................................................................................... 30
12 Option SO –Synchronised Outputs .................................................................................................................. 31
13 Option CO –Controlled Outputs....................................................................................................................... 33
14 Option OD and OE –Output Disable and Output Enable ................................................................................. 34
15 Unit –to –unit Time-Tag Synchronisation ....................................................................................................... 35
15.1 Setting the Synchronisation Source............................................................................................................36
16 Software............................................................................................................................................................ 38
16.1 Files Supplied with the DSI .........................................................................................................................38
16.2 Controlling the DSI using the SpWIO Program.........................................................................................38
16.3 The RMAP plugin for the SpWIO Program ...............................................................................................39
16.4 C-language Application Programming Interface ........................................................................................39

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16.5 Waveform Handling....................................................................................................................................39
17 Troubleshooting Guide ..................................................................................................................................... 40
17.1 I cannot make a TCP/IP connection to my DSI unit....................................................................................40
17.2 I cannot send to, or receive from, one of the DSI unit’s SpaceWire ports.................................................41
17.3 My SpaceWire link(s) are disconnecting unexpectedly..............................................................................41
17.4 My API program hangs at start-up! ............................................................................................................41
17.5 My API program works for a while and then hangs... ................................................................................42
17.6 Ethernet Performance in large networks ...................................................................................................42
17.7 Waveform capture offset from event ........................................................................................................42
18 Regulatory information..................................................................................................................................... 43
18.1 EU................................................................................................................................................................43
18.2 USA .............................................................................................................................................................43
18.3 Waste Disposal ...........................................................................................................................................43
18.4 Restriction of Hazardous Substances .........................................................................................................43
19 FMECA............................................................................................................................................................... 43
20 Electrical / Mechanical Characteristics............................................................................................................. 43
20.1 Physical .......................................................................................................................................................43
20.2 Environment ...............................................................................................................................................44
20.3 Power Supply..............................................................................................................................................44
20.3.1 Power Consumption .......................................................................................................................... 44
20.3.2 Grounding for Electrical Safety.......................................................................................................... 44
20.3.3 Fuse Protection.................................................................................................................................. 44
20.3.4 Power Connector............................................................................................................................... 45
20.4 SpaceWire Connector Pinouts....................................................................................................................45
21 Statement of Volatility...................................................................................................................................... 47
21.1 Removing all information from a Unit........................................................................................................47
21.2 Security Notice............................................................................................................................................47

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1Introduction
The 4Links Diagnostic SpaceWire Interface (DSI) is a rack-mounted transparent interface that allows SpaceWire
packets to be sent and received over Ethernet via a TCP/IP socket connection. It provides remote access to a
SpaceWire network for software simulation of devices, remote monitoring and distributed system integration
activities. In addition, it provides for the detailed analysis of SpaceWire components, including routing switches.
Each packet received may be time-tagged to a resolution better than 2ns. There is no limit to the length of the
SpaceWire packets that can be transferred. Abnormal data ("errors") may be injected and monitored. The low-
level SpaceWire link start-up and operating behaviour may be modified for diagnostic purposes. Concurrent
outputs on several links may be synchronized. Waveform captures of the SpaceWire link signals may be triggered
by a very wide set of events.
The Ethernet port provides a galvanically isolated connection with a cable length of up to 100m. Attaching this to
the Internet allows world-scale connections.
Ethernet and TCP/IP provide a standard interface mechanism that is supported by all major operating systems, so
no additional software drivers are required.
The basic DSI-RG408 unit provides data transfers and may be extended with options to provide for time codes,
event reporting, waveform capture and time-tags. Most options can be added as a simple field upgrade by
replacing the removable memory card on the front panel of the unit.
This equipment is available with two, four or eight active ports which may be mounted on the front panel (see the
picture above) or on the rear panel.
1.1 Product Features
Feature
Description
1U support
3U support
SpaceWire
SpaceWire Link rate (Mbps)
400Mbps
400Mbps
Ethernet
Ethernet Speed
1Gbps
1Gbps
Ports
Number of SpaceWire ports
2/4/8
2
Power
Input supply to unit
24V DC @48W
12V DC @15W
1.2 Product Options
Option
Description
1U support
3U support
TT
Time Tags
Option
No
ER
Event/Error Reporting
Option
Standard
EI
Event/Error Injection
Option
Standard
EW
Event/Error Waveforms
Option
Standard
SO
Synchronised Outputs
Option
No
CO
Controlled Outputs
Option
No
OD
Output Disable
Option
No
OE
Output Enable
Option
No

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2Operation
This section describes the main features of the Diagnostic SpaceWire Interface.
The Diagnostic SpaceWire Interface (DSI) is a high-performance Ethernet-to-SpaceWire Bridge that can relay
traffic from a single TCP/IP Ethernet connection to up to eight concurrently-operating bidirectional SpaceWire
ports.
The DSI may be purchased with firmware that supports fewer than the eight SpaceWire connectors on the RG408
hardware platform. In this case, only the lowest-numbered SpaceWire connectors are
usable - e.g. ports 1 and 2 for 2-port firmware and ports 1-4 for 4-port firmware. The remaining ports are
disabled. Firmware upgrades to enable further ports are available from 4Links Limited.
2.1 General
The DSI is connected to an Ethernet network and passively waits for a connection from a host computer. It is
identified by an IP address that is used by the host computer to make this connection.
The connection is made using a TCP socket, which is flow-controlled and is capable of recovering from errors that
might occur on the network between the user and the EtherSpaceLink unit.
Upon making the connection, the DSI is set to a known state with the SpaceWire links disabled, the
link speed set to 10Mb/s and all the options reset. The user program must enable the SpaceWire links before data
can be sent or received. Once enabled, data is transferred, transparently, from the
SpaceWire link to the application program on the host, and also from the program to the SpaceWire link.
There is no limitation on the size of packet transfers in each direction - not even as a result of finite buffer sizes.
The user has complete control over the SpaceWire packet content and structure; a packet may be sent or
received in segments.
The host program can also control the transmission speed of the SpaceWire links. The transmit speed can be
changed at any time, including in the middle of a packet. Speed changes are transparent and do not require link
disconnection. In accordance with the standard, the SpaceWire links always start at 10Mb/s and then, when the
link(s) are established, they may be changed to the user-selected speed. All of the links on the DSI run at the same
user-selected speed, except for any that are selected to remain at the initial 10Mb/s rate.
Disconnection of the user’s program from the DSI results in the SpaceWire links being disabled and all of the DSI
options being reset.
The DSI can therefore be seen as a transparent interface - when the user program activates theSpaceWire links,
they can connect to the target SpaceWire network, and when the user program is stopped, the SpaceWire links
disconnect.
The Diagnostic SpaceWire Interface may be operated in three ways:

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By its operator from their computer keyboard, using a supplied program to generate and monitor
SpaceWire traffic manually;
Through the use of pre-designed command scripts that run standard sets of tests and analyse the results
automatically;
Using customer-created software that interacts with their SpaceWire network through the
EtherSpaceLink Application Programming interface (API) under program control.
2.2 Getting Started
As an Ethernet-to-SpaceWire bridge, the primary purpose of the Diagnostic SpaceWire Interface is to relay traffic
from a host computer to one or more SpaceWire ports, and vice-versa. This can easily be demonstrated by
connecting port 1 of the DSI back to itself using the supplied loop-back connector:
FIGURE 2-1CONNECTING THE DSI IN LOOP-BACK MODE
Using the SpWIO program, a SpaceWire packet may be sent from the host computer to the DSI’s SpaceWire port
1, from where it flows through the loop-back cable and back to port 1. From there, it will be returned to the host
computer, displayed and recorded.
Here we can see that a 4-byte EOP-terminated packet was transmitted to port 1 of the DSI, and a 4-byte packet
was then received from port 1.
Further examples in this manual will illustrate some of the advanced error-injection, error-reporting and
synchronisation features of the Diagnostic SpaceWire Interface.
2.3 Standard Diagnostic SpaceWire Interface Capabilities
All DSI units include the following capabilities:
java -jar SpWIO.jar /u 192.168.3.42
//-4Links.SpWIO (v24:20111201/v33:20110920) on Fri Sep 14 14:48:04 BST 2012
//-/u 192.168.3.42
//-Attached 192.168.3.42 is DSI-RG40x/8 v1.9 [EI,EW,ER,TT,SO], 8-ports,
//- link mode is normal at 10.0Mb/s
//-Log file is "SpWIO_20120914_144809.log"
//-Input from "(console)"
@1 2 4 6 8 eop
Tx:@1 #02 #04 #06 #08 EOP
Rx:@1 #02 #04 #06 #08 EOP

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Bridging of bidirectional streams of characters from Ethernet to SpaceWire;
The ability to support up to eight concurrently-active SpaceWire ports, depending on the configuration
purchased;
The transmit speed of the links can be set at up to 400Mb/s in steps of 1Mb/s or less;
The receive speed of the links is in excess of 400Mb/s;
Software is provided for the manual and scripted generation of SpaceWire traffic, together with a C-
language programming API for automated testing.
2.4 DSI Options
A Diagnostic SpaceWire Interface can be supplied with firmware that provides additional optional features.
Detailed information about these options can be found in section 7, “DSI Option Details”.
2.4.1 ER - Event / Error Reporting
Tokens defined as errors, that would normally be hidden (typically resulting in a link reset) and replaced by (at
most) an EEP character, can be made visible to the user. Correct, but normally hidden tokens (such as flow-
control tokens) can also be transferred to the user.
2.4.2 EW- Event / Error Waveforms
Each SpaceWire port has an associated waveform store that captures transmit and receive wire signals for that
port. Waveform captures can be triggered on a wide variety of events on that and/or other ports. It is possible,
for example, to capture wire signals for all ports after a trigger signal on one port.
Triggers include all error conditions, received data, lifting of the synchronised outputs barrier, signals on the
external SMA connectors, and user-inserted flags in the transmit data stream.
2.4.3 EI - Event / Error Injection
SpaceWire tokens that are not normally generated, because they are defined as errors, can be explicitly
inserted into the data stream:
Parity error between tokens
ESC-EOP - escape end-of-packet
ESC-EEP - escape error-end-of-packet
ESC-ESC - escape escape
Idle periods - when D and S remain constant. An extended idle period (greater than the SpaceWire
disconnect timeout, which is nominally 850 ns) should trigger a SpaceWire timeout response.
These error injection functions allow the user to determine the behaviour of SpaceWire components under
controlled error conditions.
The EI option also allows the flow-control behaviour of the SpaceWire state-machine to be altered to provoke
behaviour and errors relating to flow-control. For instance, flow-control tokens may be withheld, either partially
or completely, to explore a device’s handling of low flow-control credit. Alternatively, too many flow-control
tokens can be issued, which should eventually result in a SpaceWire error condition.

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2.4.4 TT - Time-tags
Selected events can be time-tagged with a resolution of better than 2 ns. All of the DSI’s ports use the same time
reference, so that relative time-tags between ports are consistent.
With option SO, Synchronized Outputs, it is also possible to accurately measure round-trip times for data.
Multiple EtherSpaceLink units can be linked so that their time-tags are synchronized to allow comparisons of
time-tags generated on multiple units.
DSI Version 1.0 introduced optional delta time-tags. When enabled, time-tags occurring shortly after another
time-tag (on the same link) are reported as delta times. Long intervals (>∼6.5us) result in the usual absolute time-
tag. Delta time-tags are coded using 2-bytes instead of the usual 8-bytes and thus considerably reduce traffic
when time-tags are used with high speed data.
2.4.5 SO - Synchronized Outputs
In order to test functions such as the arbitration in a routing switch, it is necessary to present inputs to the
device-under-test that are synchronized with each other. The Synchronized Outputs option allows
outputs from all or any sub-set of the ports to be synchronized at user specified points in their data streams. For
example, multiple packets may be scheduled to start their transmission at the same time, or one packet may be
started at the same time as another finishes.
From a single DSI, output synchronization is to within 2 ns.
Multiple units can be linked so that their outputs are synchronized between units as well as within.
2.4.6 CO - Controlled Outputs
It is possible to synchronise the transmission of any character in the transmit stream to an external clock
transition by using the CO option.
Low-to-high transitions on a rear-mounted SMA connector permit the transmission of traffic beyond each HOLD
character that is inserted in the transmit data stream.
Each port on the DSI has a transmit buffer of approximately 32 kbytes, which stores data characters, EOP tokens
and HOLD markers.
2.4.7 OD and OE - Output Disable and Output Enable
When testing delicate or valuable SpaceWire hardware, some users might prefer to disable all of the SpaceWire
signals from the DSI when their test system detects an abnormal condition.
The DSI’s Output Disable option (OD) responds to a high-level input signal on SMA connector pair J3-J4, and tri-
states the SpaceWire ports. When J3-J4 is not driven, the DSI behaves as it normally would.
Conversely, the DSI’s Output Enable option (OE) only enables its SpaceWire outputs when a high-level input signal
is present on SMA connector pair J3-J4, making it fail-safe. The drawback to this option is that the DSI will appear
inert unless J3-J4 is driven high, which is a non-standard behaviour.
The OD and OE options indicate “-3S-” on the DSI unit’s front-panel when its SpaceWire outputs are tri-stated.