RS±422 Serial Interface

This interface is used with bit serial devices compatible with EIA±RS±422A or CCITT V.27 and V.11 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 400 feet.

RS±422 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±5 lists the pin assignments of the RS±422 interface connector.

Table B±5. RS±422 Serial Interface Pin Assignments

Pin

Signal

Direction

 

 

 

 

 

 

 

 

1

Chassis Ground

Not applicable

 

Transmit Data + (TxD+)

From printer

 

25

 

19

Transmit Data ± (TxD±)

From printer

 

 

 

 

 

17

Receive Data + (RxD+)

To printer

 

15

Receive Data ± (RxD±)

To printer

 

 

 

 

 

7

Signal Ground

Not applicable

B±12

Host I/O Interfaces

Page 116
Image 116
Printronix L1024 manual RS±422 Serial Interface, RS±422 Interface Connector Pin Assignments