s7-400 plc goes to STOP mode..

zrawi

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• Apr 19, 2004

• #1

I have s7-400 plc with ET-200M station as a slave..
When the power for ET-200M is reset, then the plc goes to stop mode..
Which organization block (OB?) do i need to prevent it from stopping?

Please help!

Thanks!

 

fribeiro

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• Apr 19, 2004

• #2

Try OB86 and/or OB122. But you can find more details in Module Information menu.

All the best.

 

JesperMP

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• Apr 19, 2004

• #3

Try OB86 "Rack error", OB87 "Comm error", or OB122 "IO error".

But to be absolutely sure, open up the CPU diagnostics while online and an active DP error (ET200M is shutdown). The diagnostic buffer will tell you exactly which OB you are missing.

 

zrawi

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• Apr 19, 2004

• #4

Thanks! I'll try that..

 

Fiona

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• Apr 19, 2004

• #5

Hi.

Adding an empty 0B86(loss of rack fault) will prevent your PLC going into stop mode when the power to the ET200 is cycled.

Hope this helps

Fiona.

 

amradnan

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• Jul 23, 2017

• #6

could you please tell me what i have to write in each OB ( 86, 121 and 122 )? i have CPU 314 IFM

 

sigmadelta

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• Jul 23, 2017

• #7

amradnan said:

could you please tell me what i have to write in each OB ( 86, 121 and 122 )? i have CPU 314 IFM

Click to expand...

It's not obligatory to write any code. You could set a bit in each of them to tell your HMI that there was a Rack Fault in OB86, a Programming Error in OB121, or an I/O Error in OB122.