Siemens S5 Processor Fault

[marcwand]

Hey Guys,

So I am lucky enough to be neck deep with an old piece of machinery that is controlled by Siemens S5 gear.

It is here that I should say that my experience lies mostly on the Allen Bradley side of town, but that is not enough to scare me off.

I was forced to reload the PLC program after I found that the memory blocks had somehow became corrupted. The steps I took consisted of clearing out the memory, resetting all of the hardware settings to default, and transferring the program. I really didn't want to clear out the memory and reset all of the hardware settings, but this was the only way I could get a successful download to the processor.

I now have a stable processor communication wise, but the fault I now have is that it cannot see the expansion rack. I get a fault "Delayed Handshake from Peripheral", and when I go to diagnose this fault it points me to the peripheral input load block and the section of code lines up exactly with the first card of the expansion rack.

I feel that perhaps when I reset the hardware configuration settings, perhaps I messed something up to do with the expansion rack and how that is setup.

Either that, or I have some faulty hardware that I will have a lot of trouble finding spares for!!

Does anyone have any experience that they could share with me along these lines??

I am just about to sink into the manuals..

 

[marcwand]

Just in case some poor sucker finds this thread and was stumped like I was, this is what I did following the post above. Somehow I got it up and going again.

This is what I did –

• The problem was identified in the ISTACK pointing to a FB that was loading the state of the input and output cards. In our case it was falling over on a Load of PW32 which just so happened to be the start of the expansion rack.
• We checked the dip switches on the interface modules and all of the dip switches matched the variable addressing desired.
• We powered the rack back up, but we still had the same fault.
• Just for something to try, I changed the order of the load instructions for the input addressing in the FB where the fault occurred. I basically just moved the group of ones where it faulted down the list.
• I compiled the block and downloaded it to the processor.
• Put the processor into run mode.
• The friggen thing stayed in run mode!! Haha..

I then went back into the FB, put the order back the way it was… redownloaded the changes.. and no problems.

Basically all I did was recompile and download the block where the fault was occurring and we no longer have a fault.

 

[JesperMP]

Congratulations, and I applaud your perseverance.