Universal PCI Board
Hardware Installation
2-3
Onboard termination resistors can be activated individually for each serial port using jumpers JP1 through JP8.
For CP-118U-I, JP1/2/3/4/5/6/7/8 corresponds to serial port 1/2/3/4/5/6/7/8, respectively. For CP-118U,
JP1/2/3/4/5/6/7/8 corresponds to serial port 8/7/6/5/4/3/2/1, respectively. Short the jumper pins to activate
the termination resistor; leave the jumper pins open to bypass the termination resistor.
The onboard DIP switches, S1, S2, and S3, are used to select RS-232, RS-422, or RS-485 mode for each serial
port. There are 8 switches on each bank corresponding to the 8 serial ports. S3 selects between RS-232 and
RS-422/485, S2 selects between RS-422 and RS-485, and S1 selects between 2-wire and 4-wire RS-485, as
follows:
Mode
S1
S2
S3
RS-232
---
---
ON
RS-422
---
ON
OFF
4-wire RS-485
ON
OFF
OFF
2-wire RS-485
OFF
OFF
OFF
CP-138U/CP-138U-I
