CMP/1V is a RS485 glass fiber mains converter that converts RS485 electrical serial bus standard to multi-mode glass optical fiber with a ST bayonet connector. It can be used to extend the transmission distance of a serial communication or to isolate network branches. It can be mounted on a control panel with a 35 mm DIN rail and it’s very compact, only 2 DIN modules.

CMP/1V RS485 glass fiber mains is powered by 230 V mains voltage; it is fully Plug & Play and requires no drivers or DIP switches. The RS485 serial interface operates in half-duplex mode and automatically detects data direction and transmission speeds up to 250 kbps, making it easy to install in any new or existing system.

Use cases

A RS485 glass fiber mains converter is typically used to integrate multi-mode optical fiber links into an RS485 serial bus network. There are also environments where electrical equipment is prohibited, such as swimming pools, saunas, and buildings at risk of fire, where fiber optics therefore become necessary.

Advantages

In a system, it is good practice to install a RS485 glass fiber mains converter at the beginning of a multi-mode fiber run, and a repeater such as the TVV/1M on each floor. This helps reduce issues related to ground potential differences or possible power surges. Optical fiber is a perfect electrical insulator and therefore protects the RS485 bus from the propagation of lightning strikes or other atmospheric discharges.

Fiber optics isolate various branches of a network, such as the floors of a hotel or sections of a photovoltaic system, from electromagnetic interference (EMI) and power surges. Electromagnetic interference is common in these environments, so it is good practice to install two or more optical-to-electrical converters to ensure signal integrity.

Furthermore, a RS485 glass fiber mains converter allows for the regeneration of the electrical signal, thereby improving communication quality.

Protocol

CMP/1V RS485 glass fiber mains converter is completely independent of the protocol used. This means that the converter is transparent to the communication and can be used with protocols such as Modbus, BACnet, or any proprietary protocol.

This is possible because the converter operates at the logical levels, rather than at the protocol level itself. Therefore, this RS485 glass fiber mains converter can also be used in complex networks where multiple protocols are present simultaneously on the same RS485 bus.

Installation

Glass optical fiber undoubtedly performs better than synthetic optical fiber, but it is usually more expensive and more complicated to install. It requires termination at both ends, and specialized tools must be used for this operation. Once terminated, however, the bayonet connector is clearly easy to use.

For these reasons, glass optical fiber is often used only as a backbone for communication, while plastic optical fiber (POF) is preferred for shorter runs because it is easier to install.

Versatility

The RS485 glass fiber mains converter is available with other combinations of serial and fiber optic standards, or with a low voltage power supply. The CMP/1S and CMP/1Q converters, for example, accept synthetic fiber with a screw-type or Versatile Link connector, respectively. The CRP/1V and CFP/1V, on the other hand, are suitable for various serial standards, namely RS232 and RS422.

The CMM/1V  RS485 glass optical fiber converter is functionally identical to CMP/1V but operates at low voltage. All combinations of serial standards, optical fiber types, and power supply options are available in the catalog; however, special requests (such as higher data rates) can be made via the contact form.

Main features

RS485

Bayonet ST (Straight Tip)

Mechanical features

Working conditions