B&B Electronics 422PP9R Merkblatt
P#9148_422PP9R-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 422PP9R
Port-Powered RS-232
to RS-422 Converter
The 422PP9R 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 is powered from the RS-232 handshake lines DTR and RTS. Only one of these lines
must be present, and the unit will work regardless of whether the lines are high or low. Both the RS-422 driver and
receiver are enabled at all times.
To satisfy the requirements of some software, the RS-232 handshake lines are looped back (tied together). RTS is
connected to CTS, and DTR is connected to DCD and DSR.
Connections
balanced RS-422 signals. The unit is powered from the RS-232 handshake lines DTR and RTS. Only one of these lines
must be present, and the unit will work regardless of whether the lines are high or low. Both the RS-422 driver and
receiver are enabled at all times.
To satisfy the requirements of some software, the RS-232 handshake lines are looped back (tied together). RTS is
connected to CTS, and DTR is connected to DCD and DSR.
Connections
The 422PP9R 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). The RS-422 side
of the converter is pinned out as described in Table 2. When connecting to a RS-422 system, the 422PP9R must be
connected with the proper polarity as shown in Figure 1. When no data is being sent 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). The RS-422 side
of the converter is pinned out as described in Table 2. When connecting to a RS-422 system, the 422PP9R must be
connected with the proper polarity as shown in Figure 1. When no data is being sent 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
8
3
2
7
4
TD(A)-
TD(B)+
RD(A)-
RD(B)+
GND
GND
RD(A)-
TD(A)-
RD(B)+
TD(B)+
422PP9R
DB9 female
DB9 female
RS-422
Table 1 - RS-232 Pin Out
Signal
DB9 Female Pin #
TD
3
RD
2
RTS
7
CTS
8
DTR
4
DSR
6
DCD
1
GND
5
Table 2 - RS-422 Pin Out
Signal
DB9 Female Pin #
TD A (-)
8
TD B (+)
3
RD A (-)
2
RD B (+)
7
GND
4, 6