6.3 Auxiliary Channel Configuration
An auxiliary channel is provided which allows for handshaking between a QSP-200/300 RS-422/485 port and a peripheral device. This auxiliary channel may be configured in one of two ways:
RTS-CTS handshake enabled.
handshaking is disabled.
All ports must be configured in the same manner.
6.3.1 Auxiliary Channel: RTS-CTS Handshaking
The RTS-CTS handshake may be enabled so that RTS (Request To Send) is the auxiliary output signal on AuxOut+ and AuxOut- (pins 1 and 6 of the D9 female connector). Similarly, CTS (Clear To Send) is the auxiliary input signal on AuxIn+ and AuxIn- (pins 5 and 9 of the D9 female connector). This configuration is shown below.
16C550 | | RS-422/485 | |
Drivers/Receivers | |
UART | |
| | | | |
| | | DATA OUT | + |
TXD | | Driver |
| | |
| | | - |
| | | | |
| | | DATA IN |
| | | + |
RXD | | Receiver |
| | |
| | |
| | | - |
| | | | |
| | | AUX OUT |
-RTS | | | + |
| Driver |
| | | - |
| | |
| | | | |
| | | AUX IN |
| | | + |
-CTS | | Receiver |
| | |
| | |
| | | - |
| | | | |
| | | | |
| | | | | |
Figure 5. Auxiliary Channel RTS-CTS Handshaking.
QSP-200/300 User's Manual | 36 |
