Applies To:
  • CitectSCADA 5.xx

I have a KT card connecting to DH+ and a 1785-KA module to connect this to a DH-485 network. How do I address PLCs on the DH-485 network? 

To configure Citect to talk to PLCs on the (local) DH+ network, see KB article Q2094 -

Eg. For local PLC DH+ station number 2, the address will be: 1KT:0,2

Note: The address here is in the format nKT:a,x (where n=board,a=channel,x=station number). See Q2386 for information on using multiple KT cards in the one PC. For KTX cards with two channels, use 0 and 1 to access these.

To communicate with a PLC on the DH-485 network via the 1785-KA card, add an additional port and new I/O Device and use the standard addressing as above, plus the offlink addressing options -

Eg. For a KA module with station number 3 on DH+ and a PLC with station number 5 on DH-485,

the address will be: 1KT:0/B:3/L:0,5

(where /B:3 is the KA module station address and /L:0 is the KA link ID).

For more offlink addressing examples and parameters see the topic ABTCP in the Citect Help.  Note that the addressing examples given in the help refer to using Ethernet rather than DH+ as the primary connection method.