Chapter 3: Communications; Cable Pinout; Serial Port Configuration - Microcom 466 Operator's Manual

CHAPTER 3: COMMUNICATIONS

The 466 can be interfaced to PC's, mini-computers, main frames, and special purpose
machines. It is capable of serial RS-232 or optional Centronics® parallel communication. The
following sections explain the communication interfaces.
Out of the box, unless otherwise requested, the 466 communicates using serial RS-232 at
9600 bits per second, 8 data bits, 1 stop bit and no parity with both hardware and software
handshaking. This configuration may be changed as shown in Appendix C.
3.1

CABLE PINOUT

Table 2 shows the signals of the 25-pin RS-232 serial port configuration.
If serial RS-232 communication is selected and XON/XOFF hand shaking is used, the only
signals the 466 requires are the RXD, TXD, and GND signals. If hardware (CTS/RTS) hand
shaking is used, a RTS signal is provided. XON/XOFF may be disabled through software dip
switch #1 (see Section 5.3.1). The other signals are offered in the event the host computer
requires these signals.
25 TO 9 PIN
State 466 Direction
HI 8 DCD ---->---- DCD
XX 3 TXD ---->---- RXD
XX 2 RXD ----<---- TXD
HI 6 DSR ----<---- DTR
LO 7 GND ---<->--- GND
HI 20 DTR ---->---- DSR
DC 4 CTS ----<---- RTS
XX 5 RTS ---->---- CTS
HI 18 +5V
DB-25
DC = Do Not Care
XX = Indeterminate
466 Operators Manual

Serial Port Configuration

PC State 466
1 HI
2 XX
3 XX
4 HI
5 LO
6 HI
7 DC
8 XX
HI
DE-9
Table 2
25 TO 25 PIN
Direction
8 DCD ---->---- DCD
3 TXD ---->---- RXD
2 RXD ----<---- TXD
6 DSR ----<---- DTR 20
7 GND ---<->--- GND
20 DTR ---->---- DSR
4 CTS ----<---- RTS
5 RTS ---->---- CTS
18 +5V
DB-25
DC = Do Not Care
XX = Indeterminate
PC
8
3
2
7
6
4
5
DB-25
13