Chapter 5: Communications; Rs-232 Serial; Rs-232 Printer Cables; Table 8 Rs-232 Cable Configurations - Microcom 326M User Manual

5.1

RS-232 Serial

The printers provide a 9 pin female D-Sub connector, on the rear panel, for RS-232 serial
communication. The printer is configured as DCE (Data Circuit-terminating Equipment) so a
NULL modem cable is not necessary. A serial data cable is required to use serial
communications, refer to the table below for correct cable configurations.
The factory settings, unless otherwise requested, are set at 9600 baud, 8 data bits, 1 stop
bit, and no parity with both hardware and software handshaking. The baud rate is user
selectable from 1200 to 115,200 and uses software XON/XOFF flow control and/or
hardware CTS handshaking.
9 to 9 Pin Cable
DE-9
State Pin # Directions
XX 1 DCD
XX 2 TXD
XX 3 RXD
HI 4 DTR
LO 5 GND
HI 6 DSR
DC 7 RTS
XX 8 CTS
HI 9 +5V
DC = DO NOT CARE
If XON/XOFF handshaking is used, only signals RXD, TXD, and GND are required for
proper operation. If the hardware handshaking is used the CTS and RTS signals are
required. The other signals are offered in the event that the host computer requires them.
5.1.1

RS-232 Printer Cables

The 326M and 426M printers use standard cables that may be purchased through Microcom
Corporation or a local computer supply company. A NULL-modem cable is not required
because the printer is configured as DCE.
For a 25-pin serial communication port – Use a 25-pin female to 9-pin male cable.
For a 9-pin serial communication port – Use a 9-pin female to 9-pin male cable.
326M User's Guide

Chapter 5: Communications

PC
Signals /
DE-9
Pin #
DCD 1
RXD 2
TXD 3
DSR 4
GND 5
DTR 6
CTS 7
RTS 8
+5V 9
Table 8 RS-232 Cable Configurations
9 to 25 Pin Cable
DE-9
State Pin #
HI 1 DCD
XX 2 TXD
XX 3 RXD
HI 4 DTR
LO 5 GND
HI 6 DSR
DC 7 RTS
XX 8 CTS
HI 9 +5V
XX = INDETERMINATE
PC
Signals /
DB-25
Directions
Pin #
DCD
RXD
TXD
DSR 20
GND
DTR
CTS
RTS
31
8
3
2
7
6
4
5
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