Printronix L1024 - Manual (Page 116)

B–12 Host I/O Interfaces
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
25
19
Transmit Data + (TxD+)
Transmit Data – (TxD–)
From printer
From printer
17
15
Receive Data + (RxD+)
Receive Data – (RxD–)
To printer
To printer
7 Signal Ground Not applicable