AMX Modula Instruction Manual page 39

To establish external serial control:
Cable Pinouts
1.
Use a null modem cable that matches the pin diagram in FIG. 16 for RS-232 without hardware flow
control. AMX AutoPatch equipment requires pins 2, 3, and 5 only.
Or
Use a cable that matches the pin diagram in FIG. 17 for RS-422.
FIG. 16
RS-232 null modem pin diagram, no hardware flow control
FIG. 17
RS-422 pin diagram
Instructions continue on the following page.
Modula Instruction Manual
Installation and Setup
33