Quatech DSP-200/300 - Manual (Page 43)

6. Hardware Information
6.1 Auxiliary Channel Configuration
An auxiliary channel is provided which allows for handshaking between the DSP-200/300 port
and a peripheral device. This auxiliary channel may be configured in one of two ways:
v RTS-CTS handshake enabled.
v handshaking is disabled.
6.1.1 Auxiliary Channel: RTS-CTS Handshaking.
The RTS-CTS handshake may be enabled so that RTS (request to send) is the auxiliary output
signal on AUX OUT+ (pin 1) and AUX OUT- (pin 6). Similarly, CTS (clear to send) is the
auxiliary input signal on AUX IN+ (pin 5) and AUX IN- (pin 9). 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 9. Auxiliary Channel RTS-CTS Handshaking
Hardware Information 6-1