A Pair UTEK RS232 RS485 RS422 Single-Mode Single Fiber Optic MODEM RS-232 RS-485 RS-422 Optical-Fiber Converter With Optional SC FC ST Interface UT-2577SM UT-2578SM

UT-2577SM fiber optic modem supports asynchronous RS-232/485/422 communication. It is the best choice to connect remote terminal unit (RTU) with HOST or SCADA controller. It supports RS-23/485/422 asynchronous protocols; it can be mixed and matched to use 2 RS-232, RS-485 or RS-422 ports, and it supports 2 wires (half-duplex ) RS485 and 4 wires (full-duplex) RS422 mode.
The RS-485 mode supports data transmission (TXD or SD) control, this enhance the adaptation to most of the software. Optic fiber MODEM supports lots of optic connection between asynchronous serial ports. It supports 2 asynchronous serial devices to communicate under full-duplex or half-duplex via optic fiber; the communication distance can be as far as 4km at multimode, and 20km at single mode.
The fastest transmission rate for RS-232 can be 115.2K bps, and for RS-485/422 can be 460Kbps. Ports with different electronic standards can be mixed and matched to use; it is without problem to connect RS-232 devices with RS-485/422 devices. This is a good replacement of RS-232 to RS485/422 converter, which with EMI/RFT features.
UT-2577SM supports two signal data transmission: transmit and receive data. At the same time, it is with RS-485/422 data transmission auto control circuit; Zero delay conversion; all the serial ports is connected via terminal block.
UT-2577SM and UT-2578SM are a pair, you must use them at the same time.
Model: UT-2577SM + UT-2578SM single mode SC/ST/FCinterface, and US standard plug; UT-2577SM + UT-2578SM single mode SC/ST/FCinterface, and EU standard plug; UT-2577SM + UT-2578SM single mode SC/ST/FCinterface, and UK standard plug
Package included: 1 x UT-2577SM and 1 x UT-2578SM
UT-2577SM/UT-2578SM Parameters

Transmission distance: 20km
Point to point or loop circuit (point to multi point) connection
Supports RS-232, RS-422, RS-485 asynchronous protocol
RS-232, RS-422/485 working at the same time
Supports 2 bits (half-duplex) & 4 bits (full-duplex) RS-485 operating mode
Transmission rate: 460kbps max
With optional SC, FC, ST interface
Supports master-slave working mode
Slave mode: can be used as Hub
Supports RS-232/RS-485/RS-422 port
Asynchronous transmission: point to point, 460kbps
Transmission distance: single mode 20, 000/40, 000m
Operating temperature: -40 to 85 Celsius
Operating wavelength: 1, 310nm(multi-mode), 1, 310nm, 1, 550nm (single mode)
interface: RS-232: terminal block; RS-485/422: terminal block
Fiber optic port: with optional SC, FC, ST
RS-232 port: standard RS-232 3-pin terminal block, with ±15KV ESD protection. Max transmission rate can be 115.2 kbps
Input voltage: DC9-48V 200mA
RS-485/422 Port: ±15KV ESD protection, provides with 600W surge protection to each bit