AMT Datasouth Codewriter 4500 Series - Manual (Page 33)

Data Communications
23
Xon/Xoff Flow Control
Host systems that use a simple three-wire RS232 connection (TXD, RXD,
GND) accomplish flow control by using Xon/Xoff or Robust Xon/Xoff. The
printer supports these modes and may be selected from the Operator Panel.
When using a three-wire RS232 connection, the printer must still detect the
DSR signal as ON. This requirement is addressed by adding a jumper between
RTS (pin 5) and DSR (pin 20) on the DB25 male connector on the printer
(Figure 9).
Figure 9 – Three-Wire Printer to DTE Host Cable Diagram
RXD 2
TXD 3
RTS 5
GND 7
DSR 20
2 TXD
3 RXD
7 GND
DTE Host
DB25 Connector
4500 Series Printer
DB25 Connector