Serial to Fiber Converters

Serial to fiber converters, also referred to fiber optic modem (FOM), work in pairs to extend serial signals (RS232, RS485, RS422) over a multi-mode or single mode fiber, the converter simultaneously receives incoming optical signals and converts them back to the original electronic signal, allowing for full duplex (with 4 contacts) or half duplex (with 2 contacts) transmission.

UPCOM RS232/RS485/RS422 serial to fiber optic converters have been designed for harsh industrial environments and withstand a wide temperature range from -40°C to 85°C, Fiber lines are inherently resistant to EMI/RFI and transient surges, so they are ideal for data communications near heavy electrical equipment and other electrical or radio interference, and ST, SC, and FC connectors optional.

Serial Interfaces

RS-232, RS-422, and RS-485 are the most popular serial interfaces in the industrial application, RS232 is widely used in the connection of peripherals of the computer’s serial interface, runs in full-duplex mode, the speed is 9600 bps at a distance of 15 meters, Normally, Only TxD, RxD and GND ground lines are used, the remaining lines are used to control the data flow, but the transmitting and receiving lines are referenced to a common ground, so it’s susceptible to noise, and only supports point-to-point, doesn’t support multi-point communication.

The RS-422 is 4 wires for data transmission and one common GND ground wire, allows you to send and receive data on separate lines (full duplex) simultaneously, each signal uses two wires to pass the data, support a maximum transmission distance of 4000 feet (about 1219 meters) and a maximum transmission rate of 10 Mb/s.

RS485 can operate in half-duplex mode (with 2 contacts) or full-duplex (with 4 contacts), the transmission distance can reach up to 1200 meters, RS485 is used commonly as a protocol for POS, metering instruments, data acquisition and control and especially in noisy environments, which make data transmission on a higher speed and longer distance, In the RS-485 network, it allows connect up to 128 devices.

Here are some key differences of these three commonly used serial interfaces:

According to the serial protocol, there are several types serial to fiber converters on the market, including RS-232 to Fiber Converter, RS-485 to Fiber Converter, RS-422 to Fiber Converter, RS-485/422 to Fiber Converter.

UPCOM provide 3 in1 rugged, industrial grade, multi-functional RS-232/RS-485/RS-422 to single-mode fiber optic converter which can converts either full-duplex, half-duplex RS-485 or full-duplex RS-422 data up to 20km. the device is fully plug-and-play, no need for software drivers and enables the serial transmit and receive data signals when data is present. widely used in various industrial controls, distributed data acquisition and other occasions, especially suitable for power system automation, traffic control and other departments.

Besides, the device MWF501-D can be configured as a daisy-chain or a self-healing/redundant ring fiber network, when configured as a ring fiber network, the built-in self-healing feature allows the data to be transmitted clockwise or counterclockwise; therefore, failure of any individual converter will not affect other devices located on the same fiber ring, making the entire data network more robust and reliable. Please see available products as below:

RS232 to Fiber Optic Converter

RS232 to Fiber Optic Converter convert an standard full-duplex RS-232 electrical signal into light signals through a single mode or multi-mode fiber optic cable, distance can up to 20km, it provide fully transparent operation with data, clock, and common control signals, usually use a db-9 connector for the RS232 serial port, FC, SC or CT fiber connector are available. The typical application is point-to-point.

RS422/RS485 to Fiber Optic Converter

The RS-422/RS-485 to Fiber optic Converter usually use a terminal block connector for the fiber optic link. can converts either full-duplex, half-duplex RS-485 or full-duplex RS-422 data up to 20km through via a single mode or multi-mode fiber optic cable,

RS422/RS485 to fiber optic converters are installed at each end of the fiber link and provide media conversion for connectivity between a serial host/controller and multi-drop serial devices. RS422/RS485 to fiber converter provide the multi-drop connection, In the RS-485 network, it allows connect up to 128 serial devices. on the other hand, RS422 bus support connect to 64 serial device.

APPLICATION

In the application of RS232/RS422/RS485 to fiber converters, RS232/RS422/RS485 Standards can be mixed and matched, there are several connections:

●  Same data type on both side

●  One side RS232 and the other side RS485 or RS422

●  One side RS485 and the other side RS422, etc.

Daisy Chain Topology

In a Daisy Chain Topology, one Serial to fiber is attached to the next in a line or chain. A daisy chain topology can be linear, where the first and last two serial to fiber converters are not connected.

Redundant Ring Topology

In Redundant Ring Topology, serial to fiber converters are configured as a ring fiber network, the built-in self-healing feature allows the data to be transmitted clockwise or counterclockwise; therefore, failure of any individual converter will not affect other devices located on the same fiber ring, making the entire data network more robust and reliable.