Momentum and Xxmit Error code 120 - 'Could not set PLC UART'



Goals and Symptoms:

Xxmit Error code 120 - could not set PLC UART

Causes and Fixes:

The most common cause of XMIT / XXMIT error 120 "XXMIT Could Not Set PLC UART" is trying to access a Modbus port that doesn't exist. Since you have a TSX Momentum 171CCC78010 which has 2 Modbus ports, the second most common cause of error 120 "XXMIT Could Not Set PLC UART", it trying to set 2 Stop Bits in a TSX Momentum. The UART that's used for the TSX Momentum Modbus port is not capable of 2 Stop Bits (only 1).