RS422/RS485 isolator Industry with overvoltage protection

RS422/RS485 Isolator Industry with Surge Protection by Wiesemann & Theis

The RS422/RS485 Isolator Industry with surge protection (#66203) by Wiesemann & Theis offers a robust solution for galvanic isolation of RS422 devices and RS485 bus systems, complemented by integrated surge protection. With an isolation voltage of 1 kV DC and fast protective diodes that limit differential voltages to ±9 V, the isolator protects devices from equalizing currents and overvoltages, especially for transmission lines outside buildings or under unclear wiring conditions. The two RS422/RS485 interfaces (9-pin Sub-D plugs) support high transfer speeds up to 3 MBaud, ideal for applications in Industry 4.0, automation, and control technology. The automatic control in RS485 mode and transparent operation without adjustment of transmission parameters simplify installation. The DIN rail housing and external power supply (12–24 V AC/DC) via a galvanically isolated, pluggable screw terminal make the isolator optimal for industrial control cabinets. The isolator complies with strict standards for office and industrial environments and offers a five-year warranty. This article highlights the technical features, applications, and advantages of the RS422/RS485 Isolator Industry with surge protection.

Galvanic Isolation and Surge Protection

The RS422/RS485 Isolator Industry with surge protection galvanically isolates RS422 and RS485 connections between two devices or bus systems to prevent equalizing currents that can disturb control loops or damage devices. In industrial applications, where control loops often operate potential-free, equalizing currents via grounding through the control bus or a PC can impair system stability. The isolator offers an isolation voltage of 1 kV DC, ensuring robust separation between ports and increasing the lifespan of connected devices. Additionally, the integrated surge protection safeguards RS485 transceiver chips against differential voltages exceeding the typical ±12–14 V limit, which could cause damage. Fast protective diodes limit these voltages to harmless ±9 V, making the isolator especially suitable for use outside buildings or in unclear wiring scenarios where external disturbances such as lightning strikes or switching operations may occur. For example, an RS485 bus connecting sensors in an outdoor facility can be protected by the isolator against overvoltages and equalizing currents to ensure reliable communication.

Interfaces and Connectivity

The RS422/RS485 isolator features two RS422/RS485 interfaces, each implemented via 9-pin Sub-D plugs. These interfaces support both RS422 and RS485 communication and offer high data rates up to 3 MBaud, making them ideal for data-intensive automation applications. The galvanic isolation between the ports with an isolation voltage of 1 kV DC protects both sides from electrical interference, while the integrated surge protection provides additional protection from harmful voltage spikes. The isolator operates transparently, without requiring settings of transmission parameters (such as baud rate or parity), facilitating integration into existing systems. In RS485 mode, control is automatic, optimizing communication in bus systems with multiple devices. The DIN rail housing allows easy mounting in industrial control cabinets, making the isolator particularly suitable for Industry 4.0 applications. The high transmission speed and robust design ensure reliable communication even in environments with long cable runs or electromagnetic interference.

Power Supply and Energy Efficiency

The RS422/RS485 Isolator Industry with surge protection is powered by an external power supply of 12 V to 24 V AC/DC connected via a pluggable screw terminal. The power input is galvanically isolated, providing additional protection against equalizing currents and increasing the safety of the entire installation. This flexible power supply is especially advantageous in industrial environments where various power sources may be available. The energy-efficient design of the isolator minimizes power consumption and makes the device environmentally friendly. The integrated surge protection enhances system robustness by limiting harmful voltage spikes to ±9 V without impairing the capability of the power supply. This combination of galvanically isolated power supply and surge protection makes the isolator ideal for demanding scenarios such as production plants or outdoor areas where electrical disturbances occur more frequently.

Please note: The power supply is NOT included in the delivery.

Compliance and Reliability

The RS422/RS485 Isolator Industry with surge protection complies with stringent standards for immunity (EN 61000-6-2) and emissions (EN 55032:2015 + A1 Class B, EN 61000-3-2, EN 61000-3-3), qualifying it for use in residential, commercial, and industrial environments. Its high immunity ensures reliable functioning even in environments with electromagnetic interference, such as production facilities or control centers. CE marking and UL certification confirm suitability for international applications, while the robust design is intended for continuous operation. With a five-year warranty, the isolator provides a low-maintenance and durable solution for professional users. The combination of galvanic isolation, surge protection, and high transmission speed offers additional safety and stability, particularly in applications with long cable runs or complex bus systems.

Versatile Applications

The RS422/RS485 Isolator Industry with surge protection is ideal for applications requiring galvanic isolation and overvoltage protection to ensure the reliability and safety of RS422 and RS485 connections. In automation technology, the isolator protects controllers, sensors, or actuators from equalizing currents and surges caused by long cables or electrical loads. For example, an RS485 bus connecting several sensors in an outdoor facility can be protected by the isolator against disturbances from lightning strikes or switching operations to ensure precise control. In Industry 4.0, the isolator enables secure connection of devices to control buses, which is crucial for networked production processes. In data acquisition, galvanic isolation ensures precise data by eliminating equalizing currents, while surge protection safeguards interface components from harmful voltage spikes, such as when connecting RS485 sensors for environmental parameters like temperature or pressure. The DIN rail mounting makes the isolator particularly suitable for industrial control cabinets, while support for high transmission speeds (up to 3 MBaud) and automatic control in RS485 mode ensure compatibility with modern bus systems. The isolator is versatile, suitable from manufacturing facilities to building automation systems, especially in environments with increased risk of surges.

Advantages of Transparent Operation and DIN Rail Mounting

The transparent operation of the RS422/RS485 Isolator is a key advantage, as no adjustment of transmission parameters is required. This reduces configuration effort and makes the isolator compatible with a wide range of RS422 and RS485 devices, regardless of baud rate or protocol settings. The automatic control in RS485 mode optimizes communication in bus systems with multiple devices, simplifying handling in complex networks. The DIN rail housing allows easy and stable mounting in industrial control cabinets where space and order are crucial. The high transmission speed of up to 3 MBaud combined with galvanic isolation and surge protection ensures reliable communication even in environments with electrical interference. This combination of user-friendliness and robust design is especially beneficial in environments requiring fast and reliable solutions, such as industry or automation technology.

Reliable and Robust Solution for RS422/RS485 Isolation

The RS422/RS485 Isolator Industry with surge protection by Wiesemann & Theis impresses with its ease of use, high reliability, and standards compliance. With galvanic isolation, integrated surge protection, support for high transmission speeds, automatic control in RS485 mode, DIN rail mounting, and external power supply, it is the ideal solution for applications in automation technology, Industry 4.0, and data acquisition, especially in environments with increased surge risk. The five-year warranty underlines the durability and quality of this compact solution.