HP 24SII - Manual (Page 53)

PRINTER PORTS
NOTE: Printer ports using this configuration will support hardware
handshaking only. You must ensure hardware handshaking is
supported by the equipment that will connect to these ports.
Printer ports on the M24SII-V07 module using EIA-422 Protocol, 4-
wire Operation, and unidirectional Printer Sharing Mode utilize 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 HSI- Input Handshake In (-)
4 HSI+ Input Handshake In (+)
When connecting an EIA-422 device to a printer port on the M24SII-
V07 I/O module using 4-wire Operation and unidirectional Printer
Sharing Mode, the cable required to connect the two devices must
have TX+ wired to RX+, and TX- wired to RX-, HSI+ wired to HSO+,
and HSI- wired to HSO-. Please see
Figure 12 below.
M24SII-V07 Printer Port Equipment
(EIA-422, 4-wire, unidirectional) Connections
RJ-11 RJ-11
1 TX+ RX+
2 TX- RX-
3 HSI- HSO-
4 HSI+ HSO+
Figure 12: M24SII-V07 EIA-422 (4-wire) Connection
If you are connecting a device other than another BayTech product,
you must refer to the operator's manual for your equipment to
determine which pins are defined as RX+, RX-, HSO+, and HSO-.