cb-obs411 electrical mechanical data sheet - SE Spezial-Electronic ...

connectBlue10.2.2.3 External RS422 driverAn external RS422 driver could be used in a point-to-point (full duplex) application (see Figure 16).Figure 16: A complete RS422 interface.10.2.2.4 External RS422/RS485 transceiverA complete RS422/RS485 transceiver design connected to a bus system need to control the enable signals of the transceiver. TheSerialSelect signals are used for this purpose (see Table 13). The module need to be software configured to the corrected interface, seethe Serial Port Adapter AT Commands document how to configure the module to the correct serial interface. The Red/Mode pin is notallowed to be pull-down when using the SerialSelect signals (see the Pin Description section).Table 13: SerialSelect signals combinationsSerialSelect-0SerialSelect-1 RS485/RS422 Transmitter status (Active high) RS485/RS422 Receiver status (Active low)0 0 Disabled Enabled0 1 Enabled Enabled1 0 Enabled Disabled1 1 Disabled DisabledCopyright © 2010 connectBlue AB Page 34 of 42