siemens s5 100u

[alexmcsheffrey]

Hi
I have a customer of mine with a problem on a siemens s5 plc.For some reason it will not stay in run if you turn the switch to stop then run the light goes to run for about a second and the back to stop.Any ideas???
Alex

 

[OZEE]

Has it ever run? If it has run, what changed just before this started happening? Has anybody been doing any program or hardware changes? Do the lights seem to flash a pattern? What combination of lights are on?

Give us as many details as possible -- with what you've given us, there's not a chance.......

 

[alexmcsheffrey]

siemens u100

Hi
Machine has been running for years,nobody has touched the plc software they dont even have the capability of doing it.There is no sequence of flashing lights it just changes nriefly from red to green and red again when you turn the switch from stop to run.Somebody has changed the cpu,eprom and all the input and output cards and it still does the same.
Alex

 

[curlyandshemp]

Hi
I have a customer of mine with a problem on a siemens s5 plc.For some reason it will not stay in run if you turn the switch to stop then run the light goes to run for about a second and the back to stop.Any ideas???
Alex

You need to go online with the PLC with Step 5 and check the ISTACK to see what the error is.

Usually an analog card failure, an issue with DB1 or a program crash such as accessing a dataword in a datablock that does not exist

 

[alexmcsheffrey]

Hi
Thanks for the reply, there isnt a analogue card on the plc and all the cards and cpu hace been changed with no sucsess do you think it could be the back plate??
Alex

 

[curlyandshemp]

Hi
Thanks for the reply, there isnt a analogue card on the plc and all the cards and cpu hace been changed with no sucsess do you think it could be the back plate??
Alex

S5-100u series have no back plate, all the cards clip onto a 35mmDIN rail and connect via a bus cable.

The fact the CPU Run LED turns green briefly indicates the program is cycling at least once, encountering an error and halting. Without going on line to check the ISTACK you can only guess as to what the error, or its cause may be.

 

[timbo_uk]

Hi
Machine has been running for years,nobody has touched the plc software they dont even have the capability of doing it.There is no sequence of flashing lights it just changes nriefly from red to green and red again when you turn the switch from stop to run.Somebody has changed the cpu,eprom and all the input and output cards and it still does the same.
Alex

Is this a job you have been called into AFTER its gone titsup? If so then get the guys to put it back as it was before they had problems.
Have they swapped the EEProm/EProm/Ram also?
Have you the S5 software and Leads? are you able to go online and read ISTACK as suggested?
"Curlyandshemp" it could be a S5-135 or S5-155 too.

 

[alexmcsheffrey]

Yes it is after its gone tits up, i think at least two other "engineers " have been trying to fix it and have swapped loads of things.They have also swapped the eeprom.I do not have the cable or software to look and see what the problem is.In fact the customer is in Bradford do you fancy a job having a look at it for me,obviosly i will pay for your services???
Alex
if so give us a ring

 

[JERA]

Datablock ??

There can bee a problem with datablocks when you start up from EPROM.
If the code for generating datablocks automatically is not made, you don’t have the datablocks after read in of the PLC code from the EPROM. Then the CPU is going to stop shortly after start due to missing datablocks.
There can only be transferred OB, PB and FB from the EPROM no datablock.

So if you have changed hardware and read in the program from EPROM, you don’t get the datablocks in the cpu.

Is there use of datablocks in the program??

A power fault and combined with a bad battery will erase the CPU, and at restart it will automatically read the program from EPROM. Again no datablocks = error / stop

 

[timbo_uk]

Yes it is after its gone tits up, i think at least two other "engineers " have been trying to fix it and have swapped loads of things.They have also swapped the eeprom.I do not have the cable or software to look and see what the problem is.In fact the customer is in Bradford do you fancy a job having a look at it for me,obviosly i will pay for your services???
Alex
if so give us a ring 0779xxxxxxx

Alex, have you more info? Maybe you should have PM'ed me your number, I would edit the post to remove your mobile number from a public forum!

Have you more info on the machine etc? Do you have ladder listings all info etc? Or are you going in blind?

Problem for me is that the laptop (Field PG) is works (Hmm, although our old Field PG still just about runs) A little nervouse about that . I am working nights at the moment too, going in totally blind would not be good either!

Have you the files (and therefore comments) for the software itself?

Is the customer screaming for the machine?

I will try to call you anyway, but cannot promise anything yet (I hope you understand)

I am no expert PLC programmer by a long shot, but I usually get things sorted!

To be honest JERA's points make me nervous; if it is as he suggests, how the hell do you know what the DBs need to contain??? How much documentation have you?

Regards

Tim

 

[JERA]

To be honest JERA's points make me nervous; if it is as he suggests, how the hell do you know what the DBs need to contain??? How much documentation have you?

Hope that a printout is made over the datablocks, and from this take the values – then you have something to start with. Perhaps the datablock is only used as register for values from the program and not as setpoints for the program, then it is just to make the datablocks and start up.

If there is no documentation for the datablocks then make a xref for DB to see where the datablocks is used and find the points in the program and see what is used for.

 

[alexmcsheffrey]

Hi
There is plenty of other working machines with the same plc/program can we get the info from them???
ALex

 

[STEVEBOT]

If the Cpu was changed and the Battery removed from the original then the Program is gone from that CPU.
If you need to download the program you will need to have an original copy. If the other machines are exactly the same and I mean exactly there is the possibility of using their programs but care has to be used.
Questions to ask are
1. What did it originally do when it faulted i.e. went straight into stop, or some other issue.
2. If they cahnged the Eprom where did they get the other one from.
3. Have they still got all the original gear to hand.
4. Have they got the original software. I se the answer looks like no. But can they get it if it's an off the shelf machine it may be available from the Vendor (although I doubt it.

If the machines are the same and they understand the risks then yes interrogate another machine and see what the programs involve first befor e proceeding any futher, as stated if DBs are there original write points may be needed.
To coin Hill strret blues Good luck and lets be careful out there, in other words proceed with caution.

 

[lange280]

after an eprom change you have to give the machine a HARD RESET

this is done with the 2 little switches on the front of your S5 PLC

1 is the run/stop switch wich maybe have a middle setting.

below this is another switch, this one can only be pushed in one direction, and will jump back if it is released. i think its called "uhrloeshen"

Now you need to hold that second switch down, and while you are doing this, you have to set the PLC to RUN, then to STOP, then to RUN, then to STOP again. if you did this correct the little led wil flash red for a brief moment, then turn green.
Now you can let go of the second switch, and set the PLC to RUN again.