Know your gear
With the FOM Line Driver, you can use an RS-232, RS-485, or 20-mA current loop device in a multi-drop half-duplex environment with fiber optics as the transmission media. The Line Driver has a single RS-232 DB9 female connector. TX and RX are parallel with a 20-mA current loop and RS-485 interface sharing a common terminal block with a switch to select the shared interface. This will let you connect an RS-232, RS-485, or current loop device to a fiberoptic link. Additionally, there are two fiberoptic receivers and transmitters with ST or SMA style connectors supporting standard fiber cable through 200 microns.