Hardware download

I want to make a hardware download in mode RUN.

The system give me this message (see attachement)

Is safe to do it ?  Is there a chance to stop the PLC ?

If PLC stop, it make an evacuation of the site..  wich is not good..

If you think there is a possibility it would stop, tell me.

Or, would you do it ?

Thanks!

If you download a new HW-configuration, the CPU would always have to stop for a short period of time, BUT - depending on your type of CPU - it does not necessarily mean that it will be in STOP mode. It would simply freeze all inputs and outputs for a while.

You write, that there would be an evacuation if CPU stops. If CPU is just checked for a STOP mode, then it could work for you quite easy.

But often that is done by implementing a timing watchdog (like a toggle bit that has to change every xxx ms). If so, you have to make sure that your download would not exceed watchdog time.

You should test on a spare CPU and check how long download takes, before you try on live system 

regards

CubeOl

I want to make a hardware download in mode RUN.

The system give me this message (see attachement)

Is safe to do it ?  Is there a chance to stop the PLC ?

If PLC stop, it make an evacuation of the site..  wich is not good..

If you think there is a possibility it would stop, tell me.

Or, would you do it ?

Thanks!

 Hi

In the case your question is regarding to an S7-400H, have a look at SIMATIC Fault-tolerant systems S7-400H manual under chapter "17.1 System modifications during operation".

Note:
I have never seen this message before but the warning message you are having looks like relates to the "Minimum I/O retention time" parameter.

Please let us known if the answer was useful or not. I am only guessing, as the description is not really specify the HW you are working with.  So if your system is not an S7-400H ignore my comment.

So keep us posted!