Printronix MVP Series User Manual page 190

Option 77 — Reverse Channel (RC)
The Reverse Channel Interface line (pins 11 and 14) is disabled by default.
The RC interface line can be made high true when the printer status is:
ONLINE AND BUFFER ALMOST EMPTY (READY)
OFFLINE OR BUFFER ALMOST FULL (BUSY)
Option
Number
.0
.1
.2
.3
8–22
Display Configuration
Description
Disable (default).
77.0
Enable ON condition when printer is online and buffer is not full
77.1
(Ready).
Enable ON condition when printer is offline or buffer is full (Busy).
77.2
Enable low ON (true) when printer is offline and buffer is not full.
77.3
Interfaces