ICP CON 7520 RS-232 to RS-485 Converter Isolation on RS-232 12.11

The ICP CON 7520 is a robust and versatile protocol converter designed to provide a seamless and protected communication link between an RS-232 device (like a PC, PLC, or HMI) and an RS-485/RS-422 network. Its standout feature is 2500V DC isolation on the RS-232 side, which effectively protects sensitive host equipment from damaging ground loops, voltage surges, and noise commonly found on industrial communication lines.

This converter is an ideal solution for extending the range of RS-232 links and connecting devices to multi-drop RS-485 networks in industrial automation, building management, and process control environments.

Key Features & Highlights

• 2500V DC Isolation (RS-232 Side): Completely breaks ground loops by electrically isolating the RS-232 port from the RS-485 network and the power supply. This prevents damage from potential differences and suppresses noise, ensuring data integrity and protecting your equipment.

• Wide Power Supply Range: Supports a wide input voltage range of 10V to 30V DC, making it compatible with various standard industrial power sources.

• Data Rate: Supports high-speed communication with data rates up to 115,200 bps.

• Automatic Data Direction Control: Features built-in automatic send data control (ADDC™ or similar), eliminating the need for hardware handshaking lines (RTS) for controlling the RS-485 transmitter. This ensures plug-and-play compatibility with standard software and drivers.

• Robust RS-485 Network Support: Supports up to 32 nodes on the RS-485 bus. The RS-485 interface includes built-in surge protection (typically 15KV ESD) and fail-safe bias resistors to ensure a stable idle state on the network, preventing communication errors.

• Industrial-Grade Design: Housed in a compact, durable metal case with a DIN-rail mountable form factor, designed for reliable operation in harsh industrial environments.

Isolation: The Critical Protective Feature

What is Isolation?
Isolation is a design technique that separates two electrical circuits, allowing data to pass through but blocking the flow of electrical current between them. In the case of the ICP CON 7520, a special isolation component (like an opto-isolator or magnetic coupler) creates this barrier.

Why is RS-232 Side Isolation Important?

1. Eliminates Ground Loops: In industrial settings, the PC (RS-232 side) and remote RS-485 devices can be connected to different electrical grounds that may have a significant voltage difference. This difference causes a “ground loop current” to flow through the communication cable, which can corrupt data or destroy port hardware. The 7520’s isolation barrier prevents this current from flowing.

2. Protects from Voltage Surges and Transients: Electrical noise, spikes from motors/relays, or lightning-induced surges on the long RS-485 wires can travel back to the sensitive RS-232 port. The isolation barrier, combined with surge protection on the RS-485 side, blocks these high-voltage transients from reaching and damaging your computer or controller.

3. Enhances Noise Immunity: By breaking the electrical path, the isolation significantly reduces the impact of common-mode noise on the signal lines, leading to more reliable data transmission.

In short, the isolation on the ICP CON 7520 acts as a protective firewall for your valuable host equipment.

Technical Specifications

Typical Applications

• Connecting a desktop/laptop computer to an RS-485 network for programming or monitoring PLCs, drives, and sensors.

• Extending the communication distance of an RS-232 device beyond its 15-meter limit.

• Integrating legacy RS-232 equipment into modern multi-drop RS-485 control systems (e.g., in HVAC, access control, or SCADA systems).

• Creating a noise-immune and surge-protected communication link in electrically noisy environments like factories and plants.