Modbus XDriver for BCX1-9640/4040 (ModbusRTU_bCX_xxxxxxx.xdr) on comm2 for RS-485 does not work even when the comm2 port says that the driver is installed, no errors and the comm parameters match the Modbus protocol device (ie, 19.2k, n, 8, -).
bCX1-9640/4040 Controller with Modbus XDriver
Check the Communication Configuration Point (Function Code 99) of the Xdriver.
Function Code 99 is used to select between RS-485 and RS-232 when using a bCX1-9640/4040 controller with Modbus XDriver installed in Comm2 port.
Unlike the Modbus XDriver for CX ModbusRTU_2xxxxxx.xdr), the Modbus XDriver for bCX1-9640/4040(ModbusRTU_bCX_xxxxxxx.xdr) requires user to set correct value to the FileNumber attribute of Function Code 99 (Communication Configuration Point ).
If the FileNumber attribute of the Communication Configuration Point is not set to "1", the Modbus XDriver for bCX1-9640/4040(ModbusRTU_bCX_xxxxxxx.xdr) uses the default value, which is "0".
When the FileNumber attribute is set to "0", the Modbus XDriver for BCX1-96404040(ModbusRTU_bCX_xxxxxxx.xdr) considers the interface as RS-232. When the FileNumber attribute is set to "1", the Modbus XDriver for BCX1-9640/4040(ModbusRTU_bCX_xxxxxxx.xdr) considers the interface as RS-485. For detailed information, refer to the Modbus RTU XDriver User Guide on page15: Function Code 99 – Communication Configuration Point.