Instruction Manual

OPERATOR AND MAINTENANCE MANUAL
Doc No 552864 Page 16 of 22
Issue 02 June 2004
5.4 CLEARING FAULTS
Faults occurring in the 8000 Series TMR Processor, 8000 Series TMR Interface
and 8000 Series Communications Interface modules are non-latching, allowing the
system to recover automatically once the fault condition has been rectified.
Faults occurring in the I/O sub-system are latched and are cleared only by first
rectifying the fault, then pressing the Reset button on the 8000 Series TMR
Processor. Indication of the presence of a fault in the I/O sub-system is provided
by the System Healthy indicator being off.
The following events take place once a reset of the system has been initiated:
1. Fault status information, indicators and fault contacts are cleared to a ‘no
fault’ state. If the fault cause is transient fault rate, a single re-test (as a
minimum) must be passed before returning the system to a ‘no fault’ state.
2. The System Healthy indicator on the 8000 Series TMR Processor is lit to
indicate that the reset operation is complete.
During the reset operation, all programs continue to run at their normal scan rate.
There is no noticeable change in system performance and no additional
vulnerability to faults. The time required to complete the reset is related directly to
the processor scan time.