On-Line/Continuous Diagnostics; Verification; Validation - ABB Triguard SC300E Safety Manual

2.3.5

On-Line/Continuous Diagnostics

All memory reads and writes are automatically checked for errors by the processors' error
checking and correcting circuitry. Single memory errors are detected and corrected, all multiple
errors are flagged.
SIFT votes the data tables between the processors 2oo3, any errors being logged and corrected
by the processors during their 'read neighbour's data' cycle.
Corrected memory errors are logged in diagnostic history tables. These tables can be accessed
by application logic functions and be used to generate system alarms. If multiple memory errors
on a single process are detected the processor will be halted and its watchdog tripped.
The I/O 'Hot Repair' task regularly scans all configured I/O slots to determine their status. All I/O
modules have identity type registers that allow the hot repair task to confirm the status of all
fitted modules: -
• correct module type fitted and online, healthy
• correct module type fitted and offline, healthy
• module type xxx missing
• incorrect module fitted xxx, should be yyy
For further information regarding the RTTS please refer to the 'TriBuild Software Manual 008-
5206'.
For a full description of Triguard SC300E modules refer to the Triguard SC300E Product and
Application Guide (008-5112) and the relevant Module User Manuals.
2.3.6

Verification

The proving of a part of the system that it meets its specification and only its specification.
Verification can be on a small part of the system such as a single application function, or up to
the complete system with only simulated field devices and other peripherals. For example at
'The Factory Acceptance Test'.
2.3.7

Validation

The proving of the complete installed safety system includes all field devices and interfaces. For
example at 'The Site Acceptance Test'.
Issue 5 - September 2006
Page 11 of 65