Siemens 1215 cpu- ob122

[Nepiter]

Has anyone come across this kind of problem:

I have 1215FC cpu with profinet and profibus devices.

Because of one device, I would have to have an ob122 or similar block that prevents the CPU from going to stop when profibus node drops off from profibus..

But.. there is no such an OB at cpu1200.

How could I solve this problem without OB122 and he's friends, OB121 and OB86?

 

[parky]

The Ob's are not resident in the PLC you have to create one, long time since I touched siemens but I think if you program an OB as an empty block it stops it from shutting down cannot remember but remember certain OB's it is dangerous to make it stay in run mode but on coms failure it should be ok.

Have a look at this on the siemens website

https://support.industry.siemens.com/forum/gb/en/posts/how-to-configurate-ob-122/238740

 

[Nepiter]

Thank You Parky!

Too bad, 1215 cpu does not let me add ob122 manually.
First ob, which is possible to add to this CPU, is ob124.

I'm deploying hardware to the plant, so I'd need the CPU to run temporarily, without some nodes.

 

[Nepiter]

Solved:

At 1200 CPU parameters -> Startup -> Comparison preset to actual configuration-> DEFAULT:Startup CPU only if compatible.

Change to: Startup CPU even if mismatch.

Now the CPU is running without certain profibus node.

 

[Lare]

Diagnostig buffer should say which OB block is tryed to call before stop. At least that was situation on 300 and 400 series.


Error -> OB call -> NO OB -> Stop



Error -> OB call -> OB finded -> OB Error block does something (programmed alarms etc. or Only empty OB which also prevents CPU stop -> OB1 call -> Error -> OB error call -> etc..


Usually only loaded all OB blocks which were available.


1200 and 1500 errors are not so much stooping anymore and diagnostic can done on normal code easier so OB blocks isn't so much needed than earlier.


p.s There can be several errors on same OB program call.

 

[Lare]

Solved:

At 1200 CPU parameters -> Startup -> Comparison preset to actual configuration-> DEFAULT:Startup CPU only if compatible.

Change to: Startup CPU even if mismatch.

Now the CPU is running without certain profibus node.

Is this preventing also stop if CPU is started whithout IO errors and profibus error is after CPU start?


OB40 maybe keeps CPU allways running.

 

[Nepiter]

It is not possible to add ob40 to 1200 series cpu.

So far I have no idea, if CPU stays at RUN state, if IO error occurs while running.
I will test that, when we've got that profibus- node up and running.

 

[moggie]

Here is a link to the available OB's in TIA Portal

https://support.industry.siemens.co...ou-use-in-step-7-(tia-portal)-?dti=0&lc=en-GB

 

[Nepiter]

Sorry, my bad!

I just tried to manually add OB40, and that is not allowed in Tia.
But there it is on block selection, OB40 Hardware interrupt.
Too bad, that does not prevent CPU to stop, if I/O access error occurs.

I did test to drop one profibus node from network, while CPU was running.
And CPU did stay at run, when node dropped from profibus, when this selection was selected: "Startup CPU even if mismatch"

 

[moggie]

Sorry, my bad!

I just tried to manually add OB40, and that is not allowed in Tia.
But there it is on block selection, OB40 Hardware interrupt.
Too bad, that does not prevent CPU to stop, if I/O access error occurs.

I did test to drop one profibus node from network, while CPU was running.
And CPU did stay at run, when node dropped from profibus, when this selection was selected: "Startup CPU even if mismatch"

TIA Portal OB40 is for hardware interrupt for (example) High speed Counter.

For Rack/station failure try OB86

 

[Lare]

TIA Portal OB40 is for hardware interrupt for (example) High speed Counter.

For Rack/station failure try OB86

Sorrym, My bad, it is all said there on +9000 pages of
Usually only test and edit till it works.