S7-300 PLC in stop at startup due to missing profinet devices

Hello,

I have the following issue.

I have an s7-300 PLC (IM151-8) connected to one slave via Profinet. The power is the same for both, but the PLC finishes startin up before the slave. Therefore, it does no find the slave at startup and goes into STOP state: I have to warm restart it every time from Step7, but at the end of the project there will be no step7 running on any machine, but only a custom HMI. So, Is there a way to prevent the PLC from going into STOP when it does not find the Profinet slave? Or is there a way to warm restart it without using Step7 (for example, is there any bit I can use for this purpose)?

thank you a lot in advance

Hello,

first you should check why the PLC is in STOP Mode.

Do you access the Slave during Startup and get a access error ?

You can use some System Function to detect the Slave state and continue with the startup if the Slave is also running up correct.

https://support.industry.siemens.com/cs/it/en/view/98278878

Regards

Christoph

Hello,

                    In my suggestion You can add OB's.

                    This is for temp solution .  So u can add ( OB-89 , OB-100 , OB-86 ) .

                    This OB's U can add and try It..,,

Regards,

Arasan.

Hello,

The slave is a Kuka robot controller. When it finishes starting up (it takes 2 minutes more or less) the only error message I get is that the PLC is in STOP mode

Regarding the system function, since this is the very first time I use a Siemens PLC (and, therefore, Step-7), what system function I can use? 

For the PLC going into STOP, I looked into the module information - Diagnostic buffer. I can find the following sequence at startup:

- PROFINET IO: station Failure

- STOP caused by rack failure (OB not loaded or not possible, or no FRB)

-PROFINET IO: station return, event OD 16#38CB.

The details for the error are:

address of the affected station: Input address 2042; IO system ID: 100; station number: 1; Log Basic address of the IO controller: 2043; requester OB: RACK failure OB (OB86); priority class: 26; external error, outgoing event

As far as I understand, an OB86 is missing in the project (I can confirm there is no OB86 in my project, at the moment), but I don't know where and when I should call it

Hello,

the OB86 is called automatic if the station failure occurrs, it must only be created not more.

In the link i provide you find a Diagnostic Package which you can use to check the State of the IO-Device.

Regards

Christoph

Hi,

I am also facing this problem. I have created startup OB100. But how to make the PLC in startup mode till all Profinet devices are boot up? 

Hello,

pls describe your request better, it's not clear to me what you want to do.