Rockwell Automation 57C409 2 Channel Analog Input Module - Manual (Page 28)

5Ć2
Step 5. Verify that the hardware is working correctly.
With a voltmeter connected to the proper points on the
terminal strip, generate a series of different voltages or
currents. Verify that registers 0 and 1 contain digital values
proportional to the input voltages. If the digital values are
incorrect, perform the following operations:
D Systematically swap out the input module and the
processor module(s). If the problem persists, take all of
the modules except one processor module and the
input module out of the backplane. If the problem is
now corrected, one of the other modules in the rack is
malfunctioning. Reconnect the other modules one at a
time until the problem reappears. If none of these tests
reveals the problem, replace the backplane.
5.2 Bus Error
Problem: A 31" or 51" through 58" appears on the Processor
module's LED. This error message indicates that there was a bus
error when the system attempted to access the module. The possible
causes of this error are a missing module, a module in the wrong
slot, or a malfunctioning module. It is also possible that the user has
attempted to write to the wrong registers on the module. Use the
following procedure to isolate a bus error:
Step 1.
Verify that the input module is in the correct slot and that
the I/O definitions are correct.
Refer to figure 3.2. Verify that the slot number being
referenced agrees with the slot number defined in the
configuration task. Verify that the register number is in the
range 0Ć10.
Step 2. Verify that the module can be accessed.
Connect the programming terminal to the system and run
the ReSource Software. Use the I/O MONITOR to display
the eleven registers on the input module.
If the programmer is able to monitor the inputs, the
problem lies in the application software (proceed to step
3). If the programmer cannot monitor the inputs, the
problem lies in the hardware (proceed to step 4).
Step 3. Verify that the user application program is correct.
Registers 0 thru 4 of the input module cannot be written
to. If a BASIC task caused such a bus error, the error log
will contain the statement number in the task where the
error occurred. If a control block task caused the error,
you will need to search the task for any instances in which
you wrote to an input.
Step 4. 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.