Serial Converter, RS-232 DB9 F to RS-422/485 TB, Port Power Ability

Model 4WSD9TB, a universal serial converter, provides RS-232 to RS-422/RS-485 conversion using either port-power or an external power supply. Data is converted in both directions. RS-232 Transmit Data is converted to balanced RS-422 or RS-485 Transmit Data. Received RS-422/485 signals are converted to RS-232. The RS-232 port is a DB9 female connector (DCE) with pins 2(RD), 3(TD), and 5(Signal Ground) supported. Pins 7(RTS) and 8(CTS) are tied together. Pins 6(DSR), 1(DCD), and 4(DTR) are also tied together. Model 4WSD9TB has a terminal block RS-485 connector. Automatic Send Data Control - Unlike converters that require programming hardware handshaking signals to control RS-422 or RS-485 operation, Model 4WSD9TB provides automatic Send Data Control. No handshaking is required to control the RS-422/485 driver. Operating mode is set via a dipswitch. In RS-485 mode, the RS-485 driver is enabled by special circuitry which senses the RS-232 TD input. In half-duplex RS-485 mode, the receiver is enabled when not transmitting. For full-duplex operation, the receiver is set as always enabled. In RS-422 mode, the transmitter and receiver are always enabled. Port Power via RS-232 - Incoming RS-232 data lines in either the high or low state are used to port power the converter. If two RS-232 output handshake lines are available and the cable run is short, no external power is needed. The more handshake lines available, the more likely the unit can be port powered. If the handshake lines are raised and no termination is used, power efficiency is greatly increased. External Power Supply - Less than 3 mA is required to operate the converter - plus the load current. If not enough power is available from the RS-232 port, or not enough handshake lines are available, or a larger load current is required, the converter may be powered by an external 12 VDC power supply with a 2.5mm plug (tip positive). A DC jack on the converter supports external power. (Power supply not included, sold separately.)