Signal

Signal

Direction

Description

Pin

 

 

 

 

 

 

 

4

RTS

OUT

Request to send. This pin is held

 

 

 

high by the printer.

 

 

 

 

5

CTS

IN

Clear to send. This pin indicates

 

 

 

that the computer is ready to

 

 

 

receive data from the printer. The

 

 

 

printer will not proceed unless the

 

 

 

signal is high. Can be set high with

 

 

 

SelecType.

 

 

 

 

6

DSR

IN

Data set ready. This pin indicates

 

 

 

that the computer is ready to

 

 

 

receive data from the printer. Can

 

 

 

be set high with SelecType.

 

 

 

 

 

SG

 

Signal ground. This pin provides a

 

 

 

ground for all the signal lines.

 

 

 

 

8

DCD

IN

Data carrier detect. Always

 

 

 

ignored.

 

 

 

 

20

DTR

OUT

Data terminal ready. This pin

 

 

 

indicates whether or not the printer

 

 

 

is ready to receive data. If the

 

 

 

printer ready protocol is not

 

 

 

selected, this pin is always high

 

 

 

(i.e. the printer is ready to receive

 

 

 

data). If printer ready protocol is

 

 

 

selected, the printer can accept

 

 

 

data when the pin level is high, and

 

 

 

cannot accept data when the pin

 

 

 

level is low. When the DTR signal

 

 

 

goes low the host computer must

 

 

 

stop sending data within 128

 

 

 

characters. Can be set high or low

 

 

 

with SelecType.

 

 

 

 

A-14 Technical Specifications