Micrologix 1500 FAULT

I have a client with a Micrologix 1500 LRP processor that faulted.

I had him send it to me so I could clear the fault. I plugged the processor into a base I have (1764 24 AWA) But I cant replicate the IO it has in the field.

I can clear the fault, but it goes into program mode. When I put the system in RUN it faults because my base (AWA) is not his base (bwa or bxb).

I am not sure it wouldn't fault because of miss matched IO.

Is there a way to clear the fault, in programmode and when the unit powers up on his base so it goes into Run mode?

Any other ideas?

THANKS,

To ignore the IO, go to the IO configuration and click on each card. At the bottom of the Expansion General Configuration tab check the Ignore Configuration Error and download.
You will have to change the base also but this will probably eliminate the chance of you seeing the fault right of that your customer had because you are downloading.

HTH

Can I chnage the base to "Any Discrete Base" without fear of repercussions when its re-installed?

Thanks

Reinstalled...you lost me. I thought you were attempting to find what faulted the controller.

Okay, so the PLC faulted, he removed the CPU, sent it to you to find the source of the fault. now, you triggered a different fault with the I/O mismatch. I think it is unlikely at this point that you will be able to identify the cause of the original fault, unless it was caused by something in the program (unlikely, but possible).

I think the best course of action is the identify the fault when (if) it happens again before removing it from the system, ideally before even cycling power or othrewise attempting to clear it. Accessing the value in S:6 from the HMI, or using a laptop with RSlinx would be two ways to do that.

SLC now have two places to store faults, so sometimes you can clear the fault and get up and running again, then look at the other address to see what it was. (Major Error = S:06, Last Major Error S:54).

I don't think the ML1500 can do that though, so it will only hold the most recent Major Error in S:6 which is now going to be I/O mismatch.

The fault is intermittent. It revolves around power issues at the facility. It has happened twice it the past 2 or 3 YEARS.

I think it may be a result of the PLC booting up quicker than the IO string, however I am unable to reproduce the error.

They don't have the means of logging on to it at the facility to tell me what the fault was.

My main concern was resetting clearing the fault in the processor so they can re-intall it in the event of another issue.

Am I making a mistake re-installing with the processor with the IO error ignore change enabled?

Does it have a memory module fitted? Does it always happen following a power cycle? How do they recover from the fault when it happens?

I don't know about Bob O's advice, not having dealt much with the Modular Micros, but the help files says:

Setting S:1/8 and re-downloading the program will cause the error to be cleared on an attempt to power up. Maybe not the best thing to do but, if the fault is recoverable and not a hard fault, it will get them going again. The only way to get to the source of the problem though will be to read the fault (at that site unfortunately) before the power is cycled.

So do you want to find out what the problem is or just ignore it and try it again by cycling power?

OkiePC said:

Does it have a memory module fitted? Does it always happen following a power cycle? How do they recover from the fault when it happens?

I don't know about Bob O's advice, not having dealt much with the Modular Micros, but the help files says:

Click to expand...

I have been told it revolves around a power up cycle, (but I havent seen it).
To recover they have a spare processor with the program and they swap it out.

They have 3 units and I believe they all have the same program and only one gives this problem.

Also I think it revolves around the faility power going down and coming up, not cycling power to the unit. (I do not know if a gnerator is envolved, but it may be)

I feel like all I can really do is clear the fault, send it back with the new configuration. In the event it happens again on this processor, I will now be able to see the last fault.

I hate to admitt it, but I think I may have been able to originaly see the fault, but I got trigger happy and cleared it, it then faulted again imediately and I couldn't go back. It was a dumb a** move, because I was in too much of a hurry.

THANKS for all the input.

OkiePC
That ignore works like or is similar to the I/O slot enables in the SLC in my little mind at least. I did it on a ML1100 or a ML1500 I can't remember and I don't have one handy to test.

We had this same problem with a 5/4 years ago. the plc lost its program twice and faulted once. we ended up installing a surge suppressor and it hasn't happened since.

we also had an instance when the processor faulted at power up. the problem was that one of the io cards took longer to boot up some times and faulted. we toggled the fault over ride at power up bit and it solved that problem.

regards,
james

I have a processor fault also. I am just learning on this Micrologix1500. It came out of one of our OEM machines. We have software ordered but it hasn't arrived yet. The base is a LRP24BWA. I just connected power to it on the work bench and it comes up faulted. In the machine it is connected to 4 I/O cards. I have 110v on the bottom and 24 vdc on the top. It has a memory module also. Anyway I can reset this fault without the software? Fault light blinking and COMM1 blinking. Toggled the RUN switch but no help. Trying to get it set up so we can get familiar with it when our software gets here. Any help would be appreciated.