Rockwell Automation T8160 Trusted TMR Interface - Manual (Page 75)

Trusted TM TMR Module T8160
Issue 13 May 13 PD-T8160 75
5.1.1. I/O Processor
During each scan cycle, the I/O processor votes input data into its local RAM and transfers it to the
shared RAM, making it available to the Trusted
TM TMR Processor via the Inter-Module Bus. After
being processed by the Trusted TM TMR Processor, output data is placed into the shared RAM and read
by the I/O Processor into its local RAM and written to the outputs.
The I/O processor also shares in managing the system overhead. This overhead includes:
5.1.2. Watchdog Operation
The module contains two types of watchdog:
1. A triplicated module watchdog
2. A system watchdog.
The module watchdog is an individual timer watchdog, one for each processor slice. After a time-out
on one processor slice, the relevant watchdog resets that slice. The module re-synchronises all three
processor slices after the reset.
The system watchdog ‘pet‘ signal is controlled by the processor module. A time-out will cause the
Trusted
TM TMR Interface immediately to disable the I/O Safetybus on all three module processor
slices, causing a system shut-down. The Trusted TM TMR Interface then assumes the ‘Standby’ mode.
.
• Background I/O processor tests (voter tests, EPROM tests and local RAM tests).
• I/O module tests (I/O module voter tests, logic loopback tests and co-ordinating other I/O
module tests).
• Fault filtering and reporting.