GE / Emerson Shared Tags.

[moistcat]

Hi All, i'm upgrading a [3x] GE 30-90 system that extensively uses %G Global Genius Tags via Genius bus.


This is changing to RX3i (CPE310) platform using EGD communications.



The issue is that %G data was used as command/status bits from isolated SCADA terminals at each PLC. SCADA would write it to a PLC which would then update the data in all others. A different SCADA could also write the same bit to its PLC which would then push to all others.


Is there a way to replicate this bi-directional functionality using EGD protocol? Or will it be required to create new produc/consum tags that will be consumed from other PLCs, that will then be OR'd to set the %G bits locally.

 

[Steve Bailey]

Genius is at heart a producer/consumer network model. It seems to me you should be able to identify which PLC produces the %G data and which PLCs are the consumers. Then duplicate that in the EGD exchanges. It doesn't matter whether the %G bits produced by a PLC were set by SCADA or by ladder logic.

 

[moistcat]

The issue is that all SCADA are isolated, so any SCADA can write to the exact same %G bit of its assigned PLC.

Produced / Consumed doesn't seem to work quite the same, as the produced tags are also the consumed tags, if that makes sense...
If PLCA needs to allow PLCB to write into its %G007 tag,
but PLCA also needs to be able to write its own %G007 tag, which gets pushed to PLCB.

 

[Steve Bailey]

Does that mean that when %G7 is true, it means the same thing, no matter which device set it?
Is the data being shared through the global data setup in the GBC hardware configuration, or are one or more of the PLC sending Genius datagrams?
Will your company allow you to post a backup of the project file? Failing that, would they be willing o let you send it to me? I can try to help you sort it out.