How far is the effective communication distance of multimode optical fiber?

The pocket RS485 optical modem adopts large-scale FPGA design and supports the fiber optic MODEM of asynchronous RS-485 communication interface. This device is the best choice for connecting the remote terminal unit (RTU) to the host (HOST) or distributed data acquisition system ( SCADA ) controller , with a high performance-price ratio. Using ordinary multi-mode optical fiber, the effective communication distance is up to 4KM, using ordinary single-mode optical fiber, the effective communication distance can reach more than 40KM, and the communication rate of the serial port can reach 921.6KBPS.
Since optical fiber is used as the transmission medium, the threats to communication equipment from lightning, surges, electromagnetic interference, etc. in harsh environments can be completely avoided, while the investment in lightning surge protection equipment used when using copper wires is saved.
◆ It can automatically detect and control RS-485 data flow without using handshake signals to control the data flow direction;
◆ It has the ability to automatically detect the baud rate of serial port signals;
◆ It can automatically detect when the device receives no light and the power of the other device is off, or the optical fiber is broken, and indicate it on the LED;
◆ The network management interface of the rack-mounted equipment adopts SNMP;
◆ The serial channel can transmit asynchronous serial data with adaptive baud rate from 300-921.6Kbps;
◆ The lightning protection of the serial port interface reaches the IEC61000-4-5 (8/20μS) differential mode: 6KV impedance (2Ω); common mode: 6KV, impedance (2Ω) standard;
◆ It can form the topology of E1 serial port converter (A)—E1 optical fiber modem (B)—optical serial port modem (C);
◆ External AC220/5V power adapter, and DC-48V/5V power adapter can also be configured;
◆ Built-in power supply with multiple power supply options: AC220V, DC-48V/DC24V, etc., supports AC+DC dual power backup mode.
◆ Fiber part
Fiber: single fiber and dual fiber
Fiber interface: FC/SC/ST/LC (SFP)
Wavelength: 850nm/1310nm multi-mode; 1310nm/1550nm single mode
without relay Transmission distance: 20~120Km
Typical transmission power :
Single mode 1310/1550nm: ≥-9dBm
Multimode 850nm: -18dBm
Multimode 1310nm: -25dBm
Acceptance sensitivity range: -28dBm~- 40dBm
Product Features
1. Provide 1 RS-485 serial port/1 RS422 serial port/1 RS232 serial port and 2 fiber optic interfaces + 1 DIP switch , adopt fully transparent transmission mode, compatible with any communication protocol or data format (single-mode single fiber, optical port SC, transmission distance 20 kilometers);
2. Support multiple fiber optic networking modes: point-to-point communication, fiber optic cascading, and fiber optic redundant ring network self-healing protection and other data communication modes;
3. Adopt data flow automatic control technology, automatically detect serial port rate, automatically identify and control data transmission direction;
4. Input voltage : DC12-55V (dual power supply redundant backup), power supply supports overload protection and anti-reverse connection protection;
5. Protection level: IP40, lightning protection, surge protection, anti-static interference, DIN rail type, metal shell, fanless design;
6. Working temperature : -40 ℃ ~ + 85 ℃ (industrial grade materials)
Share to: