AutoCAD LT supports Houston Instrument plotter models DMP-52, DMP-61, DMP-62, DMP-62MP, DMP-161, and DMP-162 with an RS-232C serial I/O port.
Use a three-wire cable to connect the plotter and the computer as shown in the following diagram:
Set the plotter to communicate at 9600 baud with 8 data bits, no parity, 1 stop bit, and XON/XOFF protocol. The way to do this depends on the plotter model.
DMP-50 and DMP-60 series - before plotting the first time, press ENTER and then Scale UR on the plotter to activate Menu mode. Then follow the instructions in the plotter manual to set the communication parameters. You perform this setup only once. On some plotters, you must press the paper size button between consecutive plots.
DMP-61MP and DMP-62MP - AutoCAD LT supports eight pens on plotters.