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Rs–232 serial interface – Printronix L1024 User Manual

Page 113

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B–9

Host I/O Interfaces

RS–232 Serial Interface

This interface is used with bit serial devices compatible with EIA RS–232C or

CCITT V.24 standards. The interface circuit characteristics are compatible with

the Electronic Industry Association Specification.

The printer is configured as Data Terminal Equipment (DTE).

The serial data transfer baud rate is selectable from the control panel. The input

format consists of a single start bit, 7 or 8 data bits, and one or two stop bits. The

operator can set the number of data bits from the control panel. The data bits are

interpreted with the least significant bit first. The operator can also set parity

checking via the control panel. The printer interface uses a first–in/first–out

buffer with the size selectable from the control panel. The asynchronous interface

accepts data as it is provided by the host computer.

The maximum cable length from the host computer to the printer is 50 feet.

RS–232 Interface Connector Pin Assignments

The printer provides a 25–pin DB–25S connector on the rear panel for

connection of a serial interface cable. Table B–4 lists the pin assignments of the

RS–232 interface connector.

Table B–4. RS–232 Serial Interface Pin Assignments

Pin

Signal

Direction

1

Chassis Ground

Not applicable

2

Transmit Data (TxD)

From printer

3

Receive Data (RxD)

To printer

4

Request To Send (RTS)

From printer

5

Clear To Send (CTS)

To printer

6

Data Set Ready (DSR)

To printer

7

Signal Ground

Not applicable

8

Carrier Detect (CD)

To printer

11, 14

Reverse Channel (RC)

(no connects)

From printer

20

Data Terminal Ready (DTR)

From printer