Vijeo Citect and Avantyds OTB Modbus problem.


Thread Starter

Calle Lundin

Hi! I have a problem trying to connect a Advantys OTB 1S0DM9LP to Vijeo Citect through MODBUS RTU.

The register that the OTB works with is 2000 X0-X11 for inputs and 2100 X0-X7 for outputs.

The Citect works with different registers, i think. 30000 for inputs and 40000 for outputs.

The protocol i'm using is the Twido modbus RTU (modbus30). somewhere i saw that modbus30 uses %M and %MW for digital and registers, but how do i change my OTB unit to use %M instead of default registers?

I've tried everything, modbus connection works good when i connect the OTB to the Advantys Config softwere.

Could anybody help me out with the right settings or how to proceed?



calle [at]

MPA from Slovakia


OTB works with two data areas: static ones and user data table

%MW2000:X0 up to X11 - is in user data table so you should to define it by software first. If you didn't you will find the same data in static area what is %MW0:X0 up to X11 - inputs

%MW2100:X0 up to X7 you can find in static place in %MW100:X0 up to X7 - outputs

Second point is modbus addressing:
%MW0 is same as 400001
%MW100 is same as 400101
don't use 3xxxx registers - even it's dedicated to input words these distributed I/Os don't use this approach.

MPA from =S= Slovakia