ABB FI820F | Serial Fieldbus Interface Module
ABB FI820F | Serial Fieldbus Interface Module - Image 2
ABB FI820F | Serial Fieldbus Interface Module - Image 3
ABB FI820F | Serial Fieldbus Interface Module - Image 4

ABB FI820F | Serial Fieldbus Interface Module

  • Model: FI820F
  • Brand: ABB
  • Series: AC 800F / Compact 800F
  • Core Function: Serial communication interface for fieldbus protocols
  • Type: Fieldbus Module
  • Key Specs: 2 Channels, RS232/485/422, 38.4 kBaud
Category: SKU: FI820F ABB

Description

Key Technical Specifications

Parameter Value
Manufacturer ABB
Model Number FI820F (3BDH000031R1)
Product Type Serial Fieldbus Interface Module
Channels 2 Independent Serial Ports
Interfaces RS232, RS485 (Half-Duplex), RS422 (Full-Duplex)
Baud Rate Up to 38.4 kBaud
Protocols Modbus RTU, ASCII, Generic Serial
Isolation Electrical isolation between channels and CPU
Hot Swappable Yes (with specific slot procedures)
Dimensions 155mm (H) x 125mm (D) x 28mm (W)
Weight 0.145 kg

Product Introduction

The ABB FI820F is a dual-channel serial fieldbus interface module designed for the AC 800F and Compact 800F controller families. It serves as a bridge between the central controller and serial field devices, enabling communication via standard protocols like Modbus RTU. The module is essential for integrating legacy devices or third-party instrumentation that relies on serial communication rather than Ethernet-based protocols.This unit provides two independent serial ports, configurable via cabling and software for RS232, RS485, or RS422 operation. It supports transmission speeds up to 38.4 kBaud and features electrical isolation to protect the controller from ground loops and voltage spikes. The module is installed directly into the controller’s fieldbus slots (F1-F4) and supports hot-swapping, allowing for maintenance without system shutdown.

 

Installation & Configuration Guide

Preparation

  • Verify the controller (PM802F or PM803F) is powered but ensure you are familiar with the slot configuration.
  • Identify the correct slot (F1-F4). Note that while most modules are flexible, some specific bus configurations require specific slots.
  • Safety: While hot-swapping is supported, it is safer to power down if the system is not in a redundant configuration.

Removal

  • Locate the module in the controller assembly.
  • Move the micro-switch on the module to the “locked” or “off” position (usually left) to disconnect it from the internal bus.
  • Slide the module out of the slot.

Installation

  • Insert the FI820F into the designated slot (F1-F4).
  • Slide it in until the connector seats firmly.
  • Move the micro-switch to the “active” position to engage the bus connection.
  • Connect the external wiring to the 26-pin female connector on the front panel.

Power-On & Test

  • Power up the controller.
  • Check the module status LED (usually located on the front).
  • Configure the communication parameters (Baud rate, Parity) in the Control Builder F software.
  • Test communication with a connected slave device (e.g., a Modbus drive or meter).

 

Troubleshooting Quick Reference

Symptom Probable Cause Action
No Communication Wiring error or mismatched baud rate Verify pinout (Tx/Rx) and ensure Baud rate matches the slave device.
Module Not Detected Improper seating or switch position Reseat the module; ensure the micro-switch is in the active position.
Data Errors / Noise Grounding issues Ensure RS485 shield is grounded at one end; check for electrical isolation.
LED Status Red Configuration error Check hardware configuration in Control Builder F; verify protocol selection.

 

Dimensions, Mounting & Wiring Notes

  • Dimensions: 155 mm (H) x 125 mm (D) x 28 mm (W).
  • Mounting: Direct plug-in to AC 800F controller slots.
  • Wiring: Uses a 26-pin female connector. Pinout varies by protocol (RS232 vs RS485).
    • RS485: typically uses Tx+/Rx+ and Tx-/Rx- pairs.
    • RS232: uses Tx, Rx, and GND.
FI820F ABB

FI820F ABB

FAQ

What protocols does the FI820F support?

It primarily supports Modbus RTU and ASCII, but can also function as a generic serial port for custom protocols.

Can I use this with RS485 and RS232 at the same time?

Yes, the module has two independent channels. You can configure Channel 0 for RS485 and Channel 1 for RS232 simultaneously, provided you use the correct cabling.

Is the FI820F hot-swappable?

Yes, it supports hot-swapping within the AC 800F controller. However, you must use the micro-switch on the module to logically disconnect it before physical removal to prevent bus errors.

What is the maximum speed?

The module supports baud rates up to 38.4 kBaud.

Does it support redundancy?

Yes, the module supports redundant operation when used with a redundant AC 800F controller pair.

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