Hi,

I currently have a TSX37-21 communicating with a Citect SCADA system using MODBUS and connecting via the TER port. I also have a Magelis terminal screen successfully communicating witht the PLC again using MODBUS on the Aux port. The problem is when both the Magelis screen and the Citect system are operational conflicts are occuring becuase both the Magelis screen and Citect SCADA system seem to only be capable of operating as a Modbus Master, meaning that there are two masters in the system and only one slave - the PLC.

Is there anyway to setup Citect on the TER port and the Magelis terminal on the AUX port? Would changing to the Unitel protocol make a difference? I am thinking Unitel is capable of working with the describied system but am not sure.

Cheers
Michael Fisher

 

Modbus is a master / slave system, as is Unitelway.

The TER and AUX port are identical except that the AUX port does not carry a 0v & 5Vdc connection. The AUX and TER are just parallel wired. On Modbus you can only have one Master, this is normally the HMI, and PLC is a slave. You are correct in saying that Unitelway works differently, you can have two master (HMI) and a slave and it will work.

Issue with Unitelway is you only have 8 addresses accesible in total via the TER or AUX port. When the programming cable is attached to the Micro it uses Unitelway addresses 1,2 and 3. Schneider Magelis HMI normally use two Unitelway addrresses. I suggest 4 & 5. The Citec could use Unitelway addresses 6 & 7. This is your limit.
Suggest you see if you can put the Citec SCADA on Unitelway, or look at adding a TSXSCPxxx PCMCIA card for a seperate Unitelway or Modbus network.

 

The TER port and the AUX port on the TSX37-21 are connected (internaly) at the same.
So, any config. done to one of the ports is the same for the other, the only diference is that the TER port has power supply conection.