HP 24SII - Manual (Page 47)

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-232 Protocol, 4-wire
Operation, and bidirectional Printer Sharing Mode utilize the following
pins and signals for communication:
RJ-11 PIN-OUT INFORMATION
PIN SIGNAL
EIA-232 DIRECTION DESCRIPTION
1 NC ---- No connection
2 TX Output Transmit Data
3 RX Input Receive Data
4 GND ---- Signal Ground
If you are connecting a device to a port on the M24SII-V07 module
using EIA-232 Protocol, 4-wire Operation, and bidirectional Printer
Sharing Mode, please see
Appendix A.7.2 for device adapter pinouts
and recommended cabling.