HP 24SII - Manual (Page 50)

NOTE: Ports using this configuration will support XON/XOFF
handshaking only. You must enable XON/XOFF handshaking in
configuration mode for these ports (see
Section 8.8.1 ) and on the
equipment that will connect to these ports.
Ports on the M24SII-V07 module using EIA-422 Protocol, 4-wire
Operation, and bidirectional Printer Sharing Mode use the following
pins and signals for communication:
RJ-11 PIN-OUT INFORMATION
PIN SIGNAL
EIA-422 DIRECTION DESCRIPTION
1 TX+ Output Transmit Data (+)
2 TX- Output Transmit Data (-)
3 RX- Input Receive Data (-)
4 RX+ Input Receive Data (+)
When connecting an EIA-422 device to the M24SII-V07 module using
4-wire Operation and bidirectional Printer Sharing Mode, the cable
required to connect the two devices must have TX+ wired to RX+ (and
vice versa) and TX- wired to RX- (and vice versa). Please see
Figure
10 below.
M24SII-V07 Port Equipment
(EIA-422, 4-wire, bidirectional) Connections
RJ-11 RJ-11
1 TX+ RX+
2 TX- RX-
3 RX- TX-
4 RX+ TX+
Figure 10: M24SII-V07 EIA-422 (4-wire) Connection