The RS422/RS485 Isolator Industry from Wiesemann & Theis is a robust solution for galvanically isolating RS422 devices and RS485 bus systems. With an isolation voltage of 1 kV DC, it protects interfaces against equalizing currents and electromagnetic interference, which often occur in industrial environments or over long cable runs. High transmission speeds up to 3 MBaud and the compact DIN rail housing make it ideal for installation in control cabinets.

Its transparent operation, automatic control in RS485 mode, and easy installation offer maximum user-friendliness with high system stability—perfect for applications in automation technology, Industry 4.0, and data acquisition.

Galvanic isolation – protection against equalizing currents

In industrial bus systems, even slight potential differences in control loops can cause undesirable equalizing currents. These currents impair signal quality and can damage interface components. The RS422/RS485 isolator completely separates the data lines, preventing electrical interference between connected devices or bus segments.

Typical sources of interference:

• Distant lightning strikes
• High-power industrial consumers
• Long cable runs with different grounding references

The 1 kV isolation increases the lifespan of connected devices and ensures stable operation even in complex network structures.

Interfaces and high data rates

The isolator is equipped with two RS422/RS485 interfaces, each with a 9-pin Sub-D connector. It supports:

• RS422 – low-interference point-to-point connections
• RS485 – multipoint bus connections (up to 32 devices)

With transfer rates up to 3 MBaud, the isolator is also suitable for data-intensive applications. In RS485 mode, integrated control automatically switches between transmit and receive, eliminating the need for manual configuration.

Transparent operation

Transmission parameters (baud rate, parity, stop bits) do not need to be set on the isolator. It operates transparently within the existing connection, making integration into current systems easy and ensuring compatibility with a wide range of devices.

Power supply and energy efficiency

The external supply (12–24 V AC/DC) is connected via a pluggable screw terminal and is galvanically isolated. This enhances protection and ensures that no equalizing currents flow through the power supply.

Features:

• Galvanic isolation for the power supply as well
• Flexible connection options for different power sources
• Energy-efficient design for optimized power usage

For additional surge protection, model #66203 is available.

Standards compliance and EMC safety

The isolator meets the following standards:

• EN 61000-6-2 – Immunity
• EN 55032:2015 + A1 Class B – Emissions
• EN 61000-3-2 / EN 61000-3-3 – Power quality compatibility

CE and UL certifications confirm suitability for worldwide use. The robust design enables continuous operation in demanding environments. A five-year warranty guarantees long-term operational reliability.

Typical applications

• Automation technology: Protection of controllers and sensors in RS485 fieldbus.
• Industry 4.0: Reliable communication between networked machines.
• Data acquisition: Precise data capture by avoiding electrical interference.
• Building automation: Secure connection of distributed devices via RS422.

Advantages of DIN rail mounting

The compact housing is specifically designed for DIN rail mounting in control cabinets. This design allows:

• Space-saving installation
• Neat cable management
• Fast installation and maintenance

Industry-grade interface isolation

The RS422/RS485 Isolator Industry from Wiesemann & Theis offers galvanic isolation, high data rates, transparent operation, and robust DIN rail mounting. With automatic RS485 control and standards-compliant EMC safety, it is a universal solution for protecting and stabilizing serial bus systems in industrial automation and building management technology.