7.4 AUXIN/AUXOUT Loopback
The AUXIN signal is an input from the external device, and connecting it to the AUXOUT signal provides for a loopback mode of operation. In other words, whatever signal is transmitted by the external device over the AUXIN line will be fed back to the external device over the AUXOUT line. This mode is accomplished by connecting pins 1 and 2 of the jumper blocks J11 and J12. Figure 19 shows how to select this loopback mode.
Jumpers J11-13
J11
J12
J13
AUX0_SEL0 AUX0_SEL1
RCLK0_SEL
Loopback AUXOUT to AUXIN
Figure 19 --- AUXIN/AUXOUT loopback
7.5 Half-Duplex/Full-Duplex/Auto-Toggle Selection
Using jumper blocks J14 thru J16, the transmitters and receivers of each channel can be enabled and disabled by modem control signals. This allows operation in both
The transmit drivers can be controlled by either the Data Terminal Ready (DTR) or the Request to Send (RTS) output from the UART. If a jumper is applied between pins 1 and 2 of jumper block J14, the drivers are enabled for TxD and AUXOUT when the UART's DTR signal is asserted. If a jumper is applied between pins 1 and 2 of jumper block J15, the drivers are enabled for TxD and AUXOUT when the UART's RTS signal is asserted. If neither of these jumpers is applied, the drivers remain enabled at all times. When disabled, the transmit drivers enter a
The receivers can be controlled by the inverse of the transmit enable. If a jumper is applied between pins 1 and 2 of jumper block J16, the receivers for RxD and AUXIN will be disabled when the transmit drivers are enabled and
To operate in
.of jumper blocks J15 and J16
To operate in
Quatech | 35 |
