Table 4–1:
Pin Assignments
Pin
Signal
Signal
Direction
Description
1
AA Chassis
Gnd
–
Frame (Protective) Ground
2
BA (TX)
(See Note 2)
From Printer
Printer transmits coded Ready/Busy
(DC1/DC3) or BREAK status (strap
A5 IN). ETX/ACK — Up to 1500
characters will be accepted. ETX
terminates the string. The printer
sends an ACK to the host when
transmission can resume.
3
BB (RX)
(See Note 1)
To Printer
Printer can receive serial data from
Data Source when ON LINE.
4
CA (RTS)
From Printer
Request to Send. If so strapped (A8
IN), printer is ON LINE when CA is
ON. Straps affect use of CA signal:
A8, A16, A24, A32.
5
CB (CTS)
(See Notes 3
and 4)
To Printer
Clear to Send. Set by printer.
Transmission is not inhibited and
it can operate with the host. Printer
is capable of transmitting if DC1/DC3
or BREAK protocol is used. If Serial
Interface strap B4 is IN, the host may
use CC to inhibit printer transmit.
6
CC (DSR)
(See Note 3)
To Printer
Data Set Ready. When enabled by
serial interface strap B4 IN), the
lead may be used to inhibit printer
transmitting, although it can still
receive data.
7
OV (AB)
–
Printer Signal Ground.
11
SCA-1
From Printer
Secondary Request to Send. Permits
printer status to be reflected in same
manner as CA lead.
19
SCA-2
From Printer
Secondary Request to Send. Same as
pin 11.
4–4
SETTING COMMUNICATIONS AND PRINT PARAMETERS