Hi there,

Any PLC offers online modification.

During my Getting Started tour, each time I have had to modify something I was asked to build node and restart it.

So it seems that with Proview online modifications are not available.

Am I wrong ?

Thanks,

Steve

Hi Steve,

You are in a way right. There is nothing quite like online programming like with standard plc's. There is however possible to load changes to a running system. You make the changes in you project and build your node (distribute it if it is running on a different machine). Load the changes from command line with the command:

> rt_ini -r

This will load all made changes to the real-time database and change to the new plc-program. The change will take less than 100 ms and the state of your running system should be the same.

From the runtime-monitor I think you can do the same but don't remeber what that button is called.

/Robert

Hi Robert,

Thanks for your answer.

I am wandering what happens to the Grafcet.
What happens if the modifications are done elsewhere ? Does it return to initial state ?
What happens if the modifications are done to the structure of the Grafcet itself like adding new step, Diverged sequence or Parallel Sequence... ?

What about other calculus like PID blocks ? Are they initialised ?

Again thanks.

Steve

Hi Steve,

All status variables are stored in objects in the realtime database, i.e. the Grafcet sequences and PID controllers will continue to work from the current state when a soft restart is made. It is also possible to add and remove steps in Grafcet and most of the time this will work, but there are some rare occations when it won't work, for example if you manage to remove the step that is currently active, then the sequence has to be reset before it will function again. Note also that datasetting in the develoment environment of existing objects are not transferred to the realtime objects at a soft restart.

/Claes

Hello Claes,

That sounds pretty good.

Thanks for the reply.

Best Regards,
Steve

Hi Claes,

For me, it is more like a on-line(dynamic) patching. By the way, how many restart types in Proview runtime? cold restart, warm restart or soft restart? In the designer guide, I did not get such kind of information. Thanks!

Hongfu