Rockwell Automation SC300E Trusted Bridge Module - Manual (Page 42)

Trusted™ Bridge Module 8161
Issue 2 Feb 10 PD-8161 42
5. Fault Finding and Maintenance
The Trusted™ TMR Processor provides fault monitoring, self test and diagnostics functions.
Fault Detection within a Trusted™ / SC300E system can be categorised into four regions -
Trusted™ TMR Processor and Expander Hardware
SC300E Bridge Hardware
SC300E I/O Hardware
User Application
Using current Trusted™ methods for detection of faults, the TMR Processor can monitor for failures up
to the Expander section. The TMR Processor is also able to separate Bridge hardware faults from
SC300E I/O module faults. The Triguard I/O modules carry out on-board diagnostic tests which are
relayed back to the TMR Processor via the Bridge module.
The user application can also be programmed to read error flags in the I/O module fault registers to
annunciate the detection of module faults. Second faults that leave the system unable to confirm
healthy operation will result in the TMR Processor stopping all communication with the 8161 bridge
modules, ensuring that critical outputs go to a safe state when the internal watchdogs time out.