The multi-functional CW-277M/CW-277S Optical Modem supports asynchronous communication protocol namely RS-232, RS-422 and RS-485. It takes the advantage of fiber optic, which is of high data rate and wide bandwidth, immunity to EMI/RFI and lightning damage, no ground loops, low attenuation and high security, thus enhance greatly the transmission performance of the system. It is an ideal choice to link remote terminal unit (RTU) to HOST or SCADA controller. Therefore, it fit the harsh environment that requires the communication equipment with high security to avoid thunderstruck, surge and electromagnetic interference. It is widely applied for industrial control, data collection, electricity control, LED display screen, etc. Support point-to-point connection or loop connection. Support asynchronous communication protocols of RS-232, RS-422, RS-485, and simultaneous transmission two of the three: RS232 & RS-422, or RS422 & RS-485 Support half duplex and full duplex RS-485 operation modes. Data rate up to 460Kbps Support master-slave operation mode, and slave operation mode can be used as repeater. CW-277M Multi-mode 850nm wavelength 2km transmissioon distane CW-277S Single mode 1310nm wavelength 40km transmission distance