i have been labouring for the past 1 month to achieve any form of modbus comunication between twido PLC and activeX control from both eltima and automated solutions.

i am using the twido cable, switch at postion 3 with the comm. setings (modbus, add 1, 19200, N, 1) also tried out other settings.

i can't establish any form of communication, there is no response from the plc whatsoever. the software is saying communication timed out.

reaaaaaaly need help.

 

MODBUS protocol have real time constraints thus it is not eadsy to use such software for this protocol as MODBUS frames are not sent in a single block of data... so and as it is spliced, time out occurs.

You should perhaps try to tune the software in order to find out the good frame size to avoid MODBUS frames to be sliced.