Rockwell Automation 57C411 Resolver Input Module - Manual (Page 35)

5Ć5
5.3.1 No Interrupts
Problem: The program does not execute, but no error codes are
displayed on the processor module faceplate. If interrupts are never
received by the application program and the timeout parameter in
the event definition was disabled, the task will never execute.
The watchdog timer for this module should never be disabled. Before
you can determine why the program did not execute, you must first
set the timeout parameter in the event definition. Run the program
again and proceed to section 5.3.2.
5.3.2 Hardware Event TimeĆOut
Problem: All tasks in the chassis are stopped and error code 12"
appears on the faceplate of the processor module. The interrupt has
either never occurred or is occurring at a slower frequency than the
value specified in the timeout parameter in the event definition. Use
the following procedure to isolate the problem.
Step 1.
Verify that the timeout value is set correctly.
Check the value specified in the timeout parameter in the
event definition. The unit is in ticks. Each tick is equal to
5.5 msec. The timeout value should be at least 2 ticks
greater than the interrupt frequency. It can reasonably
range up to 1.5 times the interrupt frequency.
Step 2. Verify that the user application program is correct.
Review the examples in section 4.5. Make certain that
common clock has been enabled.
Step 3. Verify that the hardware is working correctly.
Systematically swap out the input module, the processor
module (s), and the backplane. After each swap, if the
problem is not corrected, replace the original item before
swapping out the next item.
5.3.3 Hardware Event Count Limit Exceeded
Problem: All tasks in the chassis are stopped and error code 1b"
appears on the faceplate of the processor module. A hardware
interrupt has occurred but no task is waiting. Use the following
procedure to isolate the problem:
Step 1.
Verify that the user application program is correct.
Verify that your interrupt response task contains either a
WAIT ON event" or CALL SCAN_LOOP" statement that
will be executed. Check carefully to determine whether a
higher priority task is preventing the interrupt response
task from running. Make certain that the ordering of your
statements agrees with the examples in section 4.5.
Step 2. Verify that the hardware is working correctly.
Verify the hardware functionality by systematically
swapping out the input module, the processor module (s),
and the backplane. After each swap, if the problem is not
corrected, replace the original item before swapping out
the next item.