B&B Electronics 422PP9TB Leaflet
P#9147_422PP9TB-0812-1/2
www.bb-elec.com orders@bb-elec.com support@bb-elec.com
International Office: 707 Dayton Road PO Box 1040 Ottawa, IL 61350 USA 815-433-5100 Fax 433-5104
European Office: Westlink Commercial Park Oranmore Co. Galway Ireland +353 91 792444 Fax +353 91 792445
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ICS
Model 422PP9TB
Port-Powered RS-232
to RS-422 Converter
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.
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).
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).
Figure 1 - Connection to an RS-422 System
TD(B)+
RD(A)-
RD(B)+
GND
TD(A)-
GND
RD(A)-
TD(A)-
RD(B)+
TD(B)+
422PP9TB
terminal blocks
terminal blocks
RS-422
Table 1 - RS-232 Pin Out
Signal
DB-9 Female Pin #
TD
3
RD
2
RTS
7
CTS
8
DTR
4
DSR
6
DCD
1
GND
5