Document No. 422PP9TB4300 - pg. 1/2
B&B Electronics Revised November 2000
This product designed and manufactured in USA of domestic and imported parts by
Port Powered RS-232
To RS-422 Converter
CE
CE
CE
CE
Model 422PP9TB
The 422PP9TB is a port-powered two-channel RS-232 to RS-422 converter. It converts TD and RD RS-232 lines to
balanced RS-422 signals. The unit can be powered from the RS-232 handshake lines, DTR and RTS. If port-powering the
unit, at least one of these handshake lines must be present, but can be in any state. The 422PP9TB can also be powered
externally on the terminal blocks. The RS-422 driver and receiver are always enabled.
To satisfy the requirements of some software packages, the RS-232 handshake lines are looped back (tied together).
RTS is connected to CTS, and DTR is connected to DSR and DCD.
Connections
The 422PP9TB is configured to transmit both directions between an RS-232 and RS-422 system. The RS-232 side is
pinned out to connect directly into the COM port on your computer or any other DTE device (Table 1). Connections to the
RS-422 side of the converter are made through terminal blocks. When connecting to an RS-422 system, the 422PP9TB
must be connected with the proper polarity as shown in Figure 1. When no data is being sent and the driver enabled, the
RS-232 line is negative and the RS-422 line TD(A) is negative with respect to TD(B).
Table 1 - RS-232 Pin Out
Figure 1 - Connection to a RS-422 System
T D (B )+
R D (A )-
R D (B )+
G N D
T D (A )-
G N D
R D (A )-
T D (A )-
R D (B )+
T D (B )+
4 2 2 P P 9 T B
te rm in a l b lo ck s
R S -4 2 2
Signal
DB-9 Female Pin #
TD
3
RD
2
RTS
7
CTS
8
DTR
4
DSR
6
DCD
1
GND
5
Document No. 422PP9TB4300 - pg. 2/2
B&B Electronics Revised November 2000
This product designed and manufactured in USA of domestic and imported parts by
Biasing Resistors
The biasing resistors for the RS-422/RS-485 receiver are 4.7k Ohm resistors. These resistors are labeled R1 and R2
(See Figure 2). Refer to B&B Electronics RS-422/485 Application Note for further information on biasing.
Figure 2
D C D
1
3
2
5
T D
G N D
R D
R 2
4 .7 k
T D (B )+
T D (A )-
R D (B )+
R D (A )-
G N D
+ 5 V
7
8
4
6
C T S
D T R
D S R
R T S
C ircu it
P o w e r
C o n v e rsio n
R 1
4 .7 k
+ 1 2 V D C
R S -2 3 2
D B 9 fe m a le
R S -4 2 2
te rm in a l b lo ck s
Specifications
Communication:
RS-422
Data Rate:
115.2 kbps max.
Power:
Port-powered from handshake lines on the RS-232 side, or 12 to 16 VDC at 40 mA on the
terminal blocks.
Dimensions:
3.5 x 1.3 x 0.7 in (8.9 x 3.3 x 1.7 cm)
Temperature Rating:
0 to 70C
NOTE: When using an external supply, the supply should be connected only to specifically labeled power inputs
(power jack, terminal block, etc.). Connecting an external power supply to the handshake lines may damage the
unit. Contact technical support for more information on connecting an external power supply to the handshake
lines.
DECLARATION OF CONFORMITY
Manufacturer's Name:
B&B Electronics Manufacturing Company
Manufacturer's Address:
P.O. Box 1040
707 Dayton Road
Ottawa, IL 61350 USA
Model Number:
422PP9TB
Description:
9-Pin Port-Powered RS-422 Converter
Type:
Light industrial ITE equipment
Application of Council Directive: 89/336/EEC
Standards:
EN 50082-1 (IEC 801-2, IEC 801-3, IEC 801-4)
EN 50081-1 (EN 55022, IEC 1000-4-2)
EN 61000 (-4-2, -4-3, -4-4, -4-5, -4-6, -4-8, -4-11)
ENV 50204
EN 55024
Michael J. Fahrion, Director of Engineering
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