Schneider Twido permanently store memory words?


Thread Starter

Penko Mitev

Hello everybody!

Here is what I am trying to find implementation for: By default, when writing to the PLC, all memory variables are set to a value of 0. This is very awkward according to my mind because if you have a ready application which has some values it uses and suddenly the customer calls you and wants some modification of the PLC program - all values will be lost.

If not something else, I would like to let the customer have the possibility to modify Timers via the HMI and this has to be done with %MW words, but they are lost after you upload a program at a future point?

To summarize, is there a way to update the application, but do not touch %MW memory words and leave their values dependent on the execution, not to pre-configured values or 0?

Jody Gallant

We have used a lot of these twido controllers. This was a major problem we had with these when we installed them in a very large SCADA system for a local municipality. (84+) To my knowledge, and I would loved to be proved wrong, the only way to save the values, is to create an animation table, and fill it with the registers you would like saved. Then, right before you go offline to make the changes, store the current values. Then, after you download the new version, you can rewrite the stored values to the registers. It's very cumbersome, and you need to know exactly which values you need to save. There is also a bug in one version of twidosuite that will not save the values of an existing animation table. (you need to create a new one every time!!)

The one nice thing about the twido, is that it is very easy to do online changes. Unless, that is, it requires a change to a subroutine. That can't be done online.

Good luck!!
Jody, thanks for the reply. I was about to start thinking there are no twido guys around :).

What you suggest sounds cumbersome, but if it is the only solution, maybe I have to go for that. Today, I will try the Save/Restore to see if it can handle with the task and will provide the answer back.

I really like the way Twido behaves and the possibilities it gives related to its price and this is the only drawback I have encountered and I hope it will remain the only one :).

Okay, I confirm what I supposed.

When willing to backup some memory words(%MW), it is possible with the following steps:

In Twido Suite, without being connected to the PLC, choose "Memory Management" instead of the common "Connect". There you have Memory Backup/Restore.

The data is stored in a file on the PC and whatever changes you do, you can always restore the customized values.

These are my two cents, although this is not the best thing, however maybe Twido engineers have had something in mind we can't understand by doing memory dependent on the application.