User's Manual
Documentation Number 3PCIOSD1x-3903m Manual  Chapter 2  7 
B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 
B&B Electronics Ltd – Westlink Comm. Pk. – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445 
RS-232 Mode 
To configure the port for RS-232 mode, 5 jumpers must be 
set/checked. The following settings will configure the port as RS-
232: 
1.  Set four jumpers of JP2 (A-D) to the "232" (left) position. 
2.  Set JP1 to the "RTS(232)" (right) position. 
The remaining jumpers, JP4, are unused in the RS-232 mode and 
may be in either position. Figure 2 shows the jumper configuration to 
set the port for RS-232 mode with *1 clock enabled. 
Figure 2. RS-232 Mode Jumper Settings 
RS-232 Pinouts 
The DB-25 male connector on the 3PCIOSD1x cards is configured 
as standard DTE RS-232 serial port. Table 1 lists pin numbers and 
descriptors. 
Table 1: RS-232 Pinouts 
Name Description Direction DB25M Pin 
Shield Shield  ------  1 
TD Transmit Data Output  2 
RD Receive Data  Input  3 
RTS Request to Send  Output  4 
CTS Clear to Send  Input  5 
DSR Data Set Ready  Input  6 
GND Signal Ground  ------  7 
DCD Data Carrier Detect  Input  8 
DTR Data Terminal Ready  Output  20 
JP2
JP4
JP1
JP3
CONTROL
A 232
D 232
B 232
C 232
422/ 485
MODES
422/ 485
422/ 485
422/ 485
TX 422
RX 422
485
485
IN OUT
*4
*1
SD
RTS( 2 32)
TERMINAT I ON
CLOCK
8  Chapter 2  Documentation Number 3PCIOSD1x-3903m Manual 
B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 
B&B Electronics Ltd – Westlink Comm. Pk. – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445 
RS-422 Mode 
To configure the port for RS-422 mode, 7 jumpers must be 
set/checked. The following settings configure the port as RS-422: 
1.  Set the four jumpers of JP2 (A-D) to the "422/485" (right) 
position. 
2.  Set the top jumper "TX" of JP4 to the “422” (left) position. 
3.  Set the second jumper "RX" of JP4 to the “422” (left) position. 
4.  The JP1 Control (SD/RTS) jumper is unused in the RS-422 
mode and may be in either position. 
5.  The bottom jumper "Termination" of JP4 switches the 120Ω 
receiver termination resistor IN or OUT. Typically this resistor is 
not used. In some cases using high baud rates and very long 
cables, termination is needed. See B&B Electronics’ free RS-
422/485 Application Note (available on our websites), 
Termination section, page 16, for more information. Figure 3 
shows the jumper configuration to set the port for RS-422 mode 
with *1 clock enabled. 
Figure 3. RS-422 Mode Jumper Settings 
JP2
JP4
JP1
JP3
CONTROL
A 232
D 232
B 232
C 232
422/ 485
MODES
422/ 485
422/ 485
422/ 485
TX 422
RX 422
485
485
IN
OUT
*4
*1
SD
RTS( 232)
CLOCK
TERMINAT I ON










