Model FOSTCDR-INV, serial to multimode fiber optic converter, is suitable for standard industrial installations. It extend data communications up to 4 km (2.5 mi) and provides two-way optical isolation on the input and output lines.Model FOSTCDR-INV provides the most versatile connection possible between any asynchronous full- or half-duplex serial equipment. In addition to direct point-to-point connectivity, it is capable operating in multi-drop mode. This allows one serial device to communicate with up to 31 other devices around a fiber optic ring. Since the converter supports mixed serial standards, you can replace other converters and isolators and add the EMI/RFI immunity inherent to fiber optic communications. An Automatic Send Data Control circuit controls the RS-422/485 driver chip, eliminating the requirement for special software. Easy to install and configure, it has an 8-position DIP switch to set up RS-422/485 parameters and terminal blocks to connect serial signals and power. In RS-232 mode, it supports Transmit and Receive data. Handshaking signals are not passed through.A 10-30 VDC external power source is required (power supply is not included, sold separately).Model FOSTCDR-INV features an "inverted fiber state" and is suitable for applications requiring the fiber optic light to be Off in the idle state.