Problems with a Remote Rack on an SLC system.


Thread Starter

Michael Lindstrom

To All,

I have an SLC 5/04 installed in a 1747-A13 chassis with the connecting cable 1747-C9 to a four slot chassis, 1747-A4. I have had a problem where that the processor goes into fault, claiming that there is a module detected in slot
13(which there is not). The error code from the programming reference manual says the error is xx53. The value I am getting in S:6 is 3411. We have installed both chassis with the correct earthing as per the installation manual. Does anyone have a clue on how to overcome this problem.

Thank you,

Michael Lindstrom
Control and Instrumentation Engineer
[email protected]

Are there no I/O cards at all in the system right now? The SLC-5/03 will mimic a failure in the last slot of the local rack if there are no cards of any kind in the chassis, so maybe the 5/04 will as well.

Otherwise, the symptoms you describe hint at a defective I/O chassis. The backplane controller chip can get damaged, and when it does it will report either an error xx56 for total failure, or sometimes a slot error in the first or last slot (when the real problem is the backplane itself).

The diagnostics are relatively simple; start removing modules, doing "Read I/O Configuration" to give yourself a test program with the I/O configured, and toggle between RUN and PROG.

If it's intermittent, look one more time at big inductive loads, especially on relay outputs. I've seen spikes from unsupressed solenoids exceed the 1500 VDC isolation and baffle the backplane IC. Defining a fault routine
in the SLC may help you diagnose which outputs changed "just before" the fault.

Good luck,

Ken Roach
A-B Seattle
[email protected]
I have seen this error when the C9 cable has a loose connection in either rack, or a broken wire.
Best to disconnect the cable and re-configure for just the A13, Then run the processor to see if the fault occurs.

Regards, David Pilt
AP Controls
Brisbane Australia