1.Introduction Fiber modem implements advanced optic transmission technology to extend signal transmission distance up to 120km on single-core fiber.It can convert data type among RS232, RS422 and RS485 by one circuit or multi-circuit. With features of HV-free,electromagnetic-free and thunder-lightning protection, fiber modem is widely used in industrial control, automatic electricity system, and traffic control etc. 2.feature 1.Comply with EIA RS-232/485/422 standard. 2.Industrial-grade design, SMT arts and crafts. 3.Self- negotiate without delayed 4.Asynchronous transmission, In point-to-point mode, RS422 connector convert with fiber optic. 5.Self-detect the rate of serial port, distinguish and control direction of data transmission. 6.The largest communication rate:120Kbps 7.External power supply 9V DC or 220V AC, dispense with steeling electricity of serial port, high adaptability. 8.Single or multimode optional, FC/SC/ST optional. 9.Operating Wavelength:1310nm/1550nm(single mode), 1310nm, 1550nm 10.Multimode communication reach 2 km, single mode reaches 120 km. 11.Power and video status indicators LED can monitor the system operating conditions 12.Plug and play , Hot-swap function 13.Support centralized management 19" 2U or 16 rack-mount chassis 3.specific 1.Optic wavelength: 1310/1550nm, 1310nm, 1550nm 2.Optic interface: FC/SC/ST 3.Transmission rate: self-adaptive 300pbs~115.2kpbs 4.Operating mode: fiber to RS-232/422/485 and vice versa. 5.Power: DC 9V 6.Operating temperature:-0~70°C; 7.Operating humidity: 0~95%(no-condensing)