Communicating with Citect and Twido using Modbus RTU


Thread Starter


Need help in communicating Twido PLC with Citect-scada using Modbus-RTU. Couldn't get any proper documentation.

Please provide any documentation links if possible.
The absence of an answer in two weeks should be a sign that there probably isn't any cookbook recipe for the task you've got.

There is a 28 page document (it looks like the Modbus chapter from a manual) here: Modbus Addressing.pdf

It seems to be a reasonable description of Twido as both a Modbus master and slave, their example uses two Twidos's talking to one another, one as a master, the other as a slave.

You'll have to locate Citect Modbus documentation and read through it and then figure which is master/client, which is slave/server and start modifying the example to fit Citect/Twido.

You might consider documenting your step-by-step activities to getting Modbus talking and publishing it here as a Twido/Citect cookbook example.