Quatech DSP-200/300 - Manual (Page 44)

6.1.2 Auxiliary Channel: Handshaking Disabled.
The DSP-200/300 ports may be configured so that the RTS-CTS handshake is disabled. This is
the default configuration. In this configuration, RTS and CTS from the 16C750 UART will be
looped back to each other. In addition, the auxiliary output and input signals will be looped back
to each other. This configuration is shown below:
RS-422/485
+
+
+
+
-
-
-
-
16C550
UART
DATA OUT
DATA IN
AUX OUT
AUX IN
TXD
RXD
-RTS
-CTS
Drivers/Receivers
Driver
Receiver
Driver
Receiver
Figure 10. Auxiliary Channel Handshaking Disabled
6-2 DSP-200/300 (Rev. I and later) User's Manual