Quatech Asynchronous Communications Adapter DSC-200/300 User Manual

Quatech Asynchronous Communications Adapter DSC-200/300 User Manual Manual pdf 29 page image

8 External ConnectionsThe DSC-200/300 provides four differential communication signals per channel.The two output signals are Transmit Data (TxD) and Auxiliary Output (AUXOUT). Thetwo input signals are Receive Data (RxD) and Auxiliary Input (AUXIN). A groundsignal is also provided.The available input signals for AUXIN are Clear To Send (CTS) and the ReceiveClock (RCLK). The available output signals for AUXOUT are Request To Send (RTS),the Transmit Clock (XCLK), and the AUXIN signal (for loopback). Either half-duplex orfull-duplex operation can be selected for each communications channel. If half-duplexoperation is selected, one of the UART's signals (either DTR or RTS) is used to enablethe transmitter drivers. The inverse of the transmitter enable can be used to enable thereceiver drivers.Factory-installed resistors allow for signal line termination in compliance withthe RS-422 and RS-485 standards. The desired termination can be selected or removedper port by applying a jumper.Configuration is done using jumpers J1 through J4 for termination selection, andjumpers J5 through J8 for interface signal routing. Each jumper block provides thesame functions for its particular channel.J7, J8J3, J4Port 2J5, J6J1, J2Port 1Signal routingTerminationChannelFigure 17 --- Jumper/Channel correspondenceCTSAUXINXCLKRTSAUXOUTRCLK123654123654RTSDTRTx ENABLETx ENABLETx ENABLE Rx ENABLEHalf-duplexif 3-6 shortedJumpers J6, J8Jumpers J5, J7Figure 18 --- Pinout of jumpers J5-J8Quatech DSC-200/300 User's Manual 29