T100MX MODBUS RTU SUPPORT

[satpalsinghs]

HI THERE

WE HAVE DEVELOPED OUR OWN MODBUS ASCII AND MODBUS RTU ACTIVEX SERVER.

BOTH MODBUS ASCII AND MODBUS RTU ACTIVEX SERVERS WORK FINE ON T100MD+ BUT T100MX ONLY SEEMS WORK WITH MODBUS ASCII AND ABSOLUTELY RESPONSE WHEN MODBUS RTU IS USED.

DTR IS ENABLED TO PROVIDE POWER TO OPTO-ISOLATOR ON COMM1 AND WE MEASURED 8V BETWEEN PIN 4&5.

SINCE MODBUS ASCII SEEMS TO WORK FINE I CAN ONLY ASSUME T100MX DOES NOT SUPPORT MODBUS RTU.

ANY IDEAS ............

MANY THANKS

SATPAL SINGH

[support]

T100MX+ and T100MD+ support both MODBUS ASCII and RTU PLCs. But earlier generation of the M-series PLC (those without the plus sign on their CPU, and firmware revision is below r30) DO NOT support RTU mode, only ASCII mode. Is your PLC an earlier model? If so, then you can only use the ASCII protocol. The MODBUS ASCII protocol works well for all the M-series PLCs.

[satpalsinghs]

THE MARKINGS ON THE CHIP INDICATE T100MX AND A WHITE LABEL BELOW INDICATING T100MX+. ??

THE TRILOGI SOFTWARE REPORTS BACK A FIMWARE VERSION T100MD+r14.

DOES THE ABOVE SUPPORT MODBUS RTU ?

MANY THANKS
SATPAL SINGH

[support]

Firmware revision r14 does not support the MODBUS RTU. It was likely to be a transitional product when the product went from MX to MX+. Only those with firmware r30 and above support the RTU.  However, it is not possible to upgrade to the latest CPU because the PLC circuit board also underwent changes that support two independent UART so the CPU for firmware r14 and r3x and above are not compatible.