uptown47
Lifetime Supporting Member
Hi all,
There's a strange hybrid system at work that involves several PLCs talking to a PC running WinCC SCADA.
This PC, in turn, talks to another PC also running WinCC SCADA which, in turn, talks to another PLC.
The reason for this was that the original PC couldn't only talk to 5 PLCs at one time so another PC was installed to talk to the remaining PLCs on the system.
Anyhoo... I'm trying to get a tag from one PLC back to another PLC via the two PCs. (see diag below...)
In the second PC I have set up an OPC tag called "myTag" that has, as it's parameter, the name of the tag that I need to address from the first PC (i.e. a parameter of "firstPLC.thisTag" which - in the first PC - equates to DB100.DW0).
When I view the tag on the screen of the 2nd PC all is well. I change the value in the PLC and the value on the 2nd PC changes.
Now... my question is... how do I then 'send' that tag to my final PLC.
In other words, how do I push that 'tag' from the 2nd PC on to an address in the last PLC ?
I really hope that makes sense?
I'm sure I'm missing something simple but I'm struggling with this.
Many thanks for any help you can give me.
;-)
There's a strange hybrid system at work that involves several PLCs talking to a PC running WinCC SCADA.
This PC, in turn, talks to another PC also running WinCC SCADA which, in turn, talks to another PLC.
The reason for this was that the original PC couldn't only talk to 5 PLCs at one time so another PC was installed to talk to the remaining PLCs on the system.
Anyhoo... I'm trying to get a tag from one PLC back to another PLC via the two PCs. (see diag below...)
In the second PC I have set up an OPC tag called "myTag" that has, as it's parameter, the name of the tag that I need to address from the first PC (i.e. a parameter of "firstPLC.thisTag" which - in the first PC - equates to DB100.DW0).
When I view the tag on the screen of the 2nd PC all is well. I change the value in the PLC and the value on the 2nd PC changes.
Now... my question is... how do I then 'send' that tag to my final PLC.
In other words, how do I push that 'tag' from the 2nd PC on to an address in the last PLC ?
I really hope that makes sense?
I'm sure I'm missing something simple but I'm struggling with this.
Many thanks for any help you can give me.
;-)