Rockwell Automation T71xx Regent+Plus Processor Modules 110 VAC, 220/240VAC and 24VDC - Manual (Page 4)

Processor Modules (T7110, 11, 12, 20, 21, and 22)
4 (Issue 1) I n d u s t r i a l
C o n t r o l S e r v i c e s
In addition to running application programs, the main processor
takes care of system overhead, such as:
• Background diagnostics including voter tests, read tests of the
EPROMs, and read-write tests of the RAM (this automatic test
is also what re-educates a new processor).
• Communications processing including reading from and
writing to the communications modules every one millisecond
and checking the communications messages at the end of each
scan.
• Fault filtering and reporting (which are available through
W INTERPRET ’s fault status and fault history features).
• Reading the communications module’s real-time clock (if a
real-time clock communications module is installed).
I/O Processor
During each scan cycle the I/O processor receives voted input data
into its local RAM and transfers it to the shared RAM — making it
available to the main processor. After being processed by the main
processor, output data are 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 system overhead. This
overhead includes:
• Background I/O processor tests (voter tests, read EPROM tests,
and read-write local RAM tests).
• I/O module tests (I/O module voter tests, logic loopback tests,
and coordinating other I/O module tests).
• Fault filtering and reporting (which are available through
W
INTERPRET
’s fault status and fault history features).
Testing and Diagnostics
Each processor module’s error detection logic is periodically tested
to ensure its continued correct operation. Testing is done using
self-tests that are automatically scheduled by each processor
module’s real-time operating system.
Front Panel Indicators and Controls
Figure 3 shows the physical features of the processor modules. The
front panel of each module contains status indicators as well as a
reset button and a memory lock keyswitch.