Printronix Series 5 - Manual (Page 192)

5–17 Interfaces
Table 5–6. RS–422 Serial Interface Connector Pin Assignments
Input Signals Output Signals Miscellaneous
Signal Pin Signal Pin Signal Pin
– Receive Data (–RD) 15 – Transmit Data (–TD) 19 Chassis Ground 1
+ Receive Data (+RD) 17 + Transmit Data (+TD) 25 Signal Ground 7
RS–422
+RD, –RD — Serial data stream differentially received by printer.
+TD, –TD — Differentially driven serial data stream for transmitting status and
control information to the host. Subject to protocol selection.
NOTE: RD and TD form signal and return paths of a differential line
signal.