Com1/Com2 Hardware Configuration; Table 11: Com3/Com4 Termination Jumpers - VersaLogic BayCat VL-EPM-31ECP Hardware Reference Manual

COM1/COM2 Hardware Configuration

Jumper block V1[1-2] enables the RS-422/485 termination resistor for COM1. Jumper V1[3-4]
enables the RS-422/485 termination resistor for COM2. The termination resistor should be
enabled for an RS-422 or RS-485 endpoint station; it should be disabled for RS-232 and RS-485
non-endpoint receivers.
Jumper
Position
1-2
3-4
Note: RS-485 non-endpoints do not require termination. If receivers are mid-line, remove this termination jumper.
EPM-31 Hardware Reference Manual

Table 11: COM3/COM4 Termination Jumpers

Function
COM1 Rx Termination
COM2 Rx Termination
Figure 21. COM1/COM2 End-point Termination Jumpers
Jumper In
RS-485/RS-422 (Note)
RS-485/RS-422 (Note)
Serial Ports
Jumper Out
RS-232 (default)
RS-232 (default)
45