FIBER OPTIC QUESTIONS
7) WHAT IS THE DIFFERENCE BETWEEN THE RS232 FIBER OPTIC CONVERTER AND THE RS232/RS485/RS422 FIBER OPTIC CONVERTER?
Answer: The RS232 to fiber optic converter is designed for operation on an RS232 port only. The RS232/RS485/RS422 to fiber optic converter is designed for operation with any of the three communications standards, RS232, RS485, or RS422. The RS232 converter uses a 9-pin D-type connector wired in a ‘Null Modem’ configuration with Pin-1 (DCD), Pin-4 (DTR), and Pin-6 (DSR) shorted together; and Pin-7 (RTS) shorted to Pin-8 (CTS). With these pre-configured Null Modem connections, even with the converter disconnected from a computer, by simply jumpering Pin-2 (TX) to PIN-3 (RX), the converter will operate in loopback mode on the fiber side. The RS232/RS485/RS422 to fiber optic converter comes with an 8-pin screw terminal block for the signal lines, providing connections to the signal lines needed for RS485 and RS422, and the RS232 TX and RX signals. In RS232 operation, the RS232/RS485/RS422 converter is internally wired in the Null Modem configuration, enabling loopback operation on the fiber cable by jumpering RS232-OUT to RS232-IN.