M500 Miniature asynchronous fiber optic modem is design to provide connection between any asynchronous serial equipment using fiber optic cable. M500 ensures RS-232 or RS-422 or RS-485 communication integrity. It supports RS-232 data signal at rate upto 115.2Kbps & RS- 422 or RS-485 data signal at rate upto 500Kbps. Different standards can be mixed & matched to allow RS-232 devices to connect RS-422 or RS-485 system. M500 allows any two pieces of asynchronous serial equipment to communicate full or half duplex over two fibers at distances upto 100 Km.