Appendix A System Interface Description
A-3
1.2 Transmission Protocols and Connection Diagrams
1.2.1 DTR - Ready/Busy
(Supported RS-232C Protocols) - Full Duplex Local Connection
This protocol uses the following signal lines:
$
Pin 1 Protective Ground (PG)
$
2 Transmit Data (TXD)
$
3 Receive Data (RXD)
$
5 Clear to Send (CTS)
$
7 Signal Ground (SG)
$
20 Data Terminal Ready (DTR)
Note:
The signal lines TXD (pin 2) and CTS (pin 5) are only necessary if the
Device Status Report is required.
The READY / BUSY DTR protocol uses the DATA TERMINAL READY
(DTR) line to control the transmission of data from the host to prevent a
buffer overflow.
Note:
Printer DTR may be connected to host DSR + CTS or only to host DSR
and a bridge between RTS and CTS.