Allen-Bradley 20-COMM-H PowerFlex RS-485 HVAC Adapter

Allen-Bradley 20-COMM-H PowerFlex RS-485 HVAC Communication Adapter

Product Description

The 20-COMM-H (20-COMM-H) is a specialized RS-485 HVAC communication adapter designed for the Allen-Bradley PowerFlex Architecture Class of AC drives. This module serves as a bridge between the drive's internal Drive Peripheral Interface (DPI) and various Building Automation Systems (BAS). Unlike standard industrial adapters, the 20-COMM-H (20-COMM-H) is engineered to natively support the specific serial protocols used in climate control and energy management environments, including Modbus RTU, Johnson Controls Metasys N2, and Siemens P1 FLN.

By installing the 20-COMM-H (20-COMM-H) internally within the drive’s communication slot, engineers can achieve full integration of fans, pumps, and blowers into a centralized HVAC network. This enables precise speed modulation based on building demand, remote fault resetting, and real-time energy consumption monitoring, which are essential for LEED-certified facilities and modern green building initiatives.

Detailed Technical Specifications

The 20-COMM-H module provides the following technical capabilities for professional HVAC integration:

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model Number: 20-COMM-H

• Communication Interface: RS-485 (Serial)

• Supported Protocols: Modbus RTU, Johnson Controls Metasys N2, Siemens Building Technologies P1 FLN

• Drive Compatibility: PowerFlex 70, 700, 700H, 700S, 753, and 755 series

• Baud Rates: 9600, 19.2k, and 38.4k bps (User configurable)

• Network Node Range: 1 to 255 (Protocol dependent)

• Internal Interface: DPI (Drive Peripheral Interface)

• Power Consumption: 150 mA at 5V DC (Sourced from host drive)

• Operating Temperature: -10 to 50 °C (14 to 122 °F)

• Status Indicators: Three LEDs for Module, Network, and Drive Status diagnostics

• Wiring Terminal: Removable 3-pin plug for RS-485 (+, -, and Shield)

Core Performance Features

• Multi-Protocol Versatility: A single hardware solution that can be switched between Modbus RTU, N2, or P1 via internal parameter settings, reducing spare parts inventory.

• Seamless DPI Integration: Provides high-speed internal data transfer, ensuring that HVAC commands (like Start/Stop and Speed Reference) are executed with minimal latency.

• Diagnostic Transparency: Onboard LEDs allow technicians to quickly distinguish between drive faults, module errors, or network wiring issues without needing a laptop.

• Energy Management Optimized: Enables the collection of drive efficiency data and run-time hours directly through the building's front-end workstation.

• Internal Mounting: Plugs directly into the drive’s communication port, requiring no external power supply or DIN rail space.