Insert hardware during run - S7-300

[mass89]

Hi,
I have some remote IO connected to my S7-317-2 PN/DP system.
I have 1 particular profinet remote IO which is not important to the system, and so I want not to stop the CPU in the case this particular remote IO fieldbus or module in the fieldbus is inserted or removed.

I read there is OB83, but looks to be only for S7-400, I have already loaded OB82.
If I remove the hardware during run, the event is:
STOP caused by removing/inserting module (OB not loaded or not possible, or no FRB).

Is this possible so be able to insert/remove without causing stop?

Regards,

 

[L D[AR2P#0.0]]

You could use SFC12 (de-activate/activate a DP/Profinet slave) and programmatically de-activate the station before it is physically removed.

 

[JesperMP]

[..]I want not to stop the CPU in the case this particular remote IO fieldbus or module in the fieldbus is inserted or removed.

LD's suggestion is the correct method when you want to remove or connect a complete station.
But if you want to remove or insert individual modules within a remote station during run, then S7-300 simply do not support that.
You would need to go to S7-400 to get Configuration-in-Run (CiR) functionality. And CiR is another huge and complex topic.

 

[mass89]

Thanks,
It turns out OB83 can be used for S7-31x CPUs, and for PN IO devices only.
So I use OB83 to check node number, if rack number any other than the one I mention then call SFC46 to stop PLC as though OB83 didn't exist.
Using OB83 if node number is the one I mention then OB83 will allow PLC to continue in run mode when hardware is inserted and removed

 

[JesperMP]

I think that you will still get a red SF or BF lamp on the CPU if you do as you suggest.
That may be a nuisance. Some customers will not accept that the PLC shows any errors.
If you use SFC12 as LD suggest, OB83 will not be called, and there will be no SF or BF.

 

[mass89]

Most likely will still get the red light yes,
This change is because the IO station connects to IO link field devices which have a higher chance of loss than any other modules (like the IO racks in a nice enclosure), I want to prevent the entire system going down if one was to be lost.

SFC12 could be used in conjunction with OB83 though if I didn't want the red light at all, whereby OB83 would call SFC12 to de-activate the station

 

[JesperMP]

I think that it must be a controlled by the operator when/if to deactivate the station.

You should use OB83 to trigger an alarm that alerts the operator that something is wrong and then he decides what to do.
If you have OB83, the line will not go down so the concern you are stating is not real.

A station should not go offline willy nilly.
If the station is supposed to be online, and it goes offline for any reason, the SF/BF should be indicated.
The problem should be dealt with in stead of automatically hiding from the operators the fact that something is wrong.

What you are doing is removing the light bulb in the oil indicator in your car because it is annoying.

 

[Lare]

Siemens have FB126 and it can be used for deactivate/activate complete stations. It isn't well documended thought, but there is WinCC sample for that.


But as Jepser noted, you should do alarm first and then let operator to decide what to do next.



http://www.plctalk.net/qanda/showthread.php?t=101535


OB blocks are only called once when there is error and after same error disappears. If there is several errors then coding to OB blocks is more difficult as error states changes on every plc scan.

 

[mass89]

I think that it must be a controlled by the operator when/if to deactivate the station.

You should use OB83 to trigger an alarm that alerts the operator that something is wrong and then he decides what to do.
If you have OB83, the line will not go down so the concern you are stating is not real.

A station should not go offline willy nilly.
If the station is supposed to be online, and it goes offline for any reason, the SF/BF should be indicated.
The problem should be dealt with in stead of automatically hiding from the operators the fact that something is wrong.

What you are doing is removing the light bulb in the oil indicator in your car because it is annoying.

As stated, the particular IO module I speak of is of low importance to the system, the main concern was that the position of the IO field devices from this module would pose risk to the entire process shutting down, so I look for options to avoid a stop which originate at something which isn't even important to the system. Of course, should the device be lost I will have an alarm set on the HMI but there's 1000 ways I could do this which is why I don't mention it

 

[Lare]

As stated, the particular IO module I speak of is of low importance to the system, the main concern was that the position of the IO field devices from this module would pose risk to the entire process shutting down, so I look for options to avoid a stop which originate at something which isn't even important to the system. Of course, should the device be lost I will have an alarm set on the HMI but there's 1000 ways I could do this which is why I don't mention it

You are aware that if you locate OB error blocks even without any code inside them, then PLC will continue on run state.
Yes it faults PLC and red leds are lid, but no stop.


Different errors calls different OB blocks and if there is no called OB block downloaded to CPU then CPU stops.