plc

[Wilso]

I hope an expert will correct me if I'm wrong here, but I was under the impression that when you select MRES, the internal memory is reset. Then when you go back to run (or stop?), it reloads the memory from the memory card if present. The 2 questions I would ask are, is the memory card present, and if so, is there anything on it? Sounds to me like the program has been wiped.

 

[balash]

if there is no program in it it should also blink SF (System Fault), if i'm correct. for MMC to be erased switch should go two times to MRES position is a procedure. this looks like the procedure was started and and then stopped in the middle.

 

[Matchu04]

Simatic ET200M

I wouldnt call myself and expert but here is my 10 pence worth. By the sound of it you have got a remote i/o module connect via Profibus (purple cable called barny hose I believe in the US)

The BF led is definalty a bus fualt issues (Communications) and if its lit on the ET200M I would say the cpu where ever it is (Another panel maybe) isnt happy. My first port of call would be to check the connects of the purple cable.

I have also had it before where someone has messed around with the EOL resistor of the profibus, but I couldnt comment to much on this as I dont want to give you the incorrect information.

Another thing if you can get online, see the attached PIC and it shows the fault buffer of the CPU and will tell you why its not happy. Missing node x.y.z

You also you may have to reset the Bus Fault externally from a input like a reset button somewhere as I know the systems that we have at work will require a reset after a bus fault has been retified.

Finaly one, the reset on the CPU, but word of warning you may, or someone may have already wipped the program as balash has stated this is done by cycaling the mres swich two in quick succesion. But again is depenant on if you have got a memory card in.

Hope that helps...

Guys correct me if Im wrong

 

[Wilso]

Didn't know you could wipe an external flash card by cycling MRES switch!

 

[balash]

Didn't you know that by reading the posts in the thread would realise he didn't do it yet electrician and he has to fix that now!

EDIT:
misread previous post on phone... sorry (sprinkling ashes on my head)

so as clarification for Wilso: yes, and if MMC contains valid data that is the only way to reset it. put MRES switch until STOP LED start blinking, then resturn to STOP and then again to MRES (MemoryRESet)

 

[Matchu04]

I wasn't implying he did, but it's the typical situation where you get called to a job where are u sure what the previous engineers have done.

Just to clarify it doesn't wipe the external card just the program that is loaded within the CPU memory, from what I understand..

 

[narsenault]

Hi, I've had the same problem with cpu BF(Bus Faults)on a Profibus system with Siemens plc and it would show now and then for no reason and the only way to clear it most of the time was to power down the faulted module as they do have a indicator light on them that also is red. Did some research on these Profibus modules and found that there was faulty versions out there, mainly V1,V2 and V3. Had to get V4 from a different supplier to be a direct replacement as V5 from Seimens would not work with our hardware. These have were change over a year ago and not one drop since which at the last we were getting one or two per month!! I'm not saying that this is the problem here but it should be ruled out.

Norm

 

[Matchu04]

Fyi..

 

[balash]

that's what i think might happen, if the card was in. and if the program was copied into RAM from card then BF would suggesting system parameters reset, specifically bus config.

Maybe.

 

[kelo]

Thanks

Thank to all of you for responding to my problem. It is now solved...