Are you refering to HMI type (touch screen LCD display) which uses MODBUS protocols or a graphic LCD that display image according to what is being sent to its serial port?
M-series PLC support MODBUS protocols so they can be used with many HMIs that support the MODBUS.
On the other hand, the TBASIC language supports sending ASCII string or binary data out of its serial port using the PRINT #1 statement or OUTCOMM 1, n statement. The exact content of the message to be sent to the graphical display is entirely dependent on the graphic display itself. Check Matrix Orbital or Scott English website for their graphical LCD display manual for details.
