Network Rail

Issue with Continuity of SSI TT Log Dats
 N TI 166 ISSUE 1

Annotation

This TI applies to:

All SSI installations using SSI4301-D7 Software in their Technicians Terminal and SSI Graphical Replay software SSI8314-B2 versions 2.0 and above.

It applies to all personnel who use SSI Graphical Replay to read SSI Technicians Terminal Logs as an aide to faulting and maintenance or incident investigation.

It applies when downloading and reading SSI Technicians Terminal Log files using SSI Graphical Replay in the circumstances detailed above..

Purpose

An issue has been discovered with the SSI4301-D7 TT software upgrade in that, in certain circumstances, data can be held for a short time in the TT buffer before being sent to the logger. Suspected causes include time adjustment with reference to the Radio Clock and temporary unavailability of the connected logging device. This can confuse the SSI Graphical Replay (SSI GR) application when the data is accessed for analysis. SSI GR SSI8314-B2, Versions 2.0 and earlier may report incorrect times in the file open dialogue and analysis. Version 2.1 will report that there are inconsistencies in the time stamps, but will usually allow analysis to proceed.

A work round has been identified to enable the data to be analysed with minimal affect on any timing. The use of this process will need to be recorded if the data is required as evidence in a serious accident investigation. Also, to maintain the chain of evidence, original log files should not be modified and copies of the log files should be used.

Автоматический перевод: