Plc S5 115u 941 Cpu Module

Hi,

I have a problem,

Some outputs are going nuts. We changed the IM card, not better, then we changed teh CPU, and everything is okay. The CPU is 15 yeears old.

Anyone had the same problem with an S5 CPU ?

Yes I had the same problem a couple of years ago, another problem quite common is cannot load program into plc (out of Memory).
on two of them the problems were different, one the memory chip the other the processor oddly enough.
I have heard a number of stories from an old freind who used to work for a company that repaired them, nearly all instances of failure on the 115's were processors.
Another good one was siemens had a faulty batch of chips used in some of the digital input cards, these sometimes did not fail for over a year(well they did not fail but were out of spec from the start). this came apparent when I installed a new system, the input cards were being seen as all 1's if you removed the card then re-booted with program in then re-installed the card it would see the inputs, once powered down & back on would fail to see the card again.

same here, have replaced 5 units of S5 115u cpu 942 with a common problem in the span of 2 years. they just quit working one day and refuse to accept backup program (keep displaying "out of memory" problem).

have tried loading small test programs and it works but not the backup ones (i guess putting an additional RAM or EEPROM will solve the issue but no point it should work without them in the first place).

since the model was discontinued we're force to use 943/44 cpu. dont know how long will it last, we're upgrading to other brand of plc though.