adccommunitymod (AutomationDirect) asked a question.
Locking VMemory
Created Date: August 30,2007
Created By: Neko
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I have a DL260 processor and a Cmore HMI talking to eachother, and i was wondering if there is any way to lock certain Vmemory addresses in the PLC. I.E. Modification of memory via the HMI is not possible at certain times or during certain stages Thanks! T
Created Date: August 31,2007
Created by: Tech Guy
One solution to this might be a time based event that turns on a tag during those times. The tag could then control the visibility of the objects that correspond to the PLC memory addresses.
The same idea could work for the various parts of the program cycle. The PLC sets a tag that controls visibility.
If you want the objects to 'remain ' on the screen, create non-functional display objects and lay them on the control object.
Created Date: August 31,2007
Created by: Steve Bailey
You can write ladder logic to lock it.
Use a one-shot contact at the start of the period where you need to lock the contents, to copy the contents of the V memory register to another V memory register. Then, for the duration of the period where you need to lock the memory, copy from the storage register to the original register. If the HMI tries to write a new value, the ladder logic will immediately overwrite it with the stored value.
Created Date: August 30,2007
Created by: Neko
I have a DL260 processor and a Cmore HMI talking to eachother, and i was wondering if there is any way to lock certain Vmemory addresses in the PLC. I.E. Modification of memory via the HMI is not possible at certain times or during certain stages
Thanks!
T