Experimental Physics and
Industrial Control System

Hi,

There are radiation dose monitor devices by using modbus tcp protocol to communicate.

The communications have succeeded to establish by using epics 3.14.12.5, modbusR1-2 combined with asynR4-9 (very old version) many years ago.

Therefore, I want to upgrade to the latest program by using modbusR2-9 combined with asynR4-30 and epics 3.14.12.5.

My settings are the same as the old version of modbusR1-2 in start.cmd file:

I noticed that there was a little difference of parameter settings in the command drvModbusAsynConfigure of new version (modbusR2-9). The manual says :"For TCP the slave address is used for the "unit identifier", the last field in the MBAP header.", and the last field in the MBAP header, as i know,  is the slave address (ranging from 1 to 247).   So, i randomly set:

drvModbusAsynConfigure("RD3R",   "Koyo3R",  111, 3, 0, 95, 0, 1160, "rpDevice")  # modbusR2-9 version, I randomly set 111

or:

drvModbusAsynConfigure("RD3R",   "Koyo3R",  0xFF, 3, 0, 95, 0, 1160, "rpDevice")  # use 0xFF to disable the parameter

however, I cannot establish  the communications by using the new version of modbus and I have no idea how to do.

The error messages are as follows:

Any help will be appreciated,  and thanks in advance !

Zhefu