I have a Zenon SCADA and there are two strings on screen, current batch and previous batch. The user needs to type in a description of the current batch. When the batch ends, a bit is set on by the PLC. This will trigger a copy of the Current batch string to previous batch string, however I can't find out how to do it. I have tried an allocation, but it seems that you can't do an allocation with a string as source, although strangely enough, it lets you create one, it just doesn't work. As the PC has a licence for Recipegroup manager, I tried to do the copy using a recipe but this doesn't work either. Is it the case that read/write of a recipe only works on a user action, like a button press, not a bit change? I'm not sure. Anyway, the main question is this, How can I copy the value in one memory string variable to another whenever the PLC sets a bit?