ABB AO801 8-Channel Analog Output Module

Description

3. Key Technical Specifications

The AO801 performs cyclic self-diagnostics and supports configurable Output Set as Predetermined (OSP) behavior during fault conditions. It provides eight unipolar current outputs (0–20 mA or 4–20 mA) and is designed for the ABB S800 I/O platform.

4. Product Introduction

The ABB AO801 is an 8-channel analog output module for the ABB S800 I/O distributed I/O system. It converts digital control values from an AC 800M controller into industry-standard 0–20 mA or 4–20 mA analog signals for controlling valves, variable-speed drives, positioners, and other process equipment.

The module is commonly deployed in power generation, oil and gas, chemical processing, pulp and paper, and water treatment facilities. Engineers value the AO801 for its predictable current output accuracy, built-in diagnostics, short-circuit protection, and straightforward integration with ABB 800xA and AC 800M automation platforms.

AO801

AO801

5. Installation & Configuration Guide

Stage 1 – Pre-Installation Preparation (10 Minutes)

⚠️ Safety First

1. Notify operations before shutdown.
2. Place the process in a safe condition.
3. Apply Lock-Out/Tag-Out (LOTO).
4. Remove cabinet power.
5. Wait at least five minutes for power supplies to discharge.

Required Tools

• ESD wrist strap
• PH1 screwdriver
• Digital multimeter
• Wire labels
• Smartphone for wiring documentation

Backup

• Save the AC 800M project.
• Record output scaling parameters.
• Photograph terminal wiring.
• Document loop assignments.

Stage 2 – Remove the Existing Module

1. Label every output loop.
2. Disconnect the terminal connector.
3. Release the module locking tab.
4. Remove the AO801 without twisting.
5. Inspect the ModuleBus connector for bent contacts or contamination.

⚠️ Keep the old module available until all outputs have been verified.

Stage 3 – Install the New AO801

1. Wear an ESD wrist strap.
2. Confirm the part number is AO801 (3BSE020514R1).
3. Insert the module until the locking mechanism clicks.
4. Reconnect the field wiring.
5. Tighten terminals to the recommended torque.

Installation Checklist

• ✔ Correct module installed
• ✔ Terminal wiring verified
• ✔ Module fully seated
• ✔ Locking latch engaged

Stage 4 – Power-Up & Commissioning

Before energizing:

• Verify the 24 VDC supply.
• Check output wiring for shorts.

Commissioning:

1. Power the S800 I/O rack.
2. Confirm the Status LED indicates normal operation.
3. Verify communication with AC 800M.
4. Download configuration if required.
5. Simulate 4 mA, 12 mA, and 20 mA outputs.
6. Confirm field devices respond correctly.

⚠️ Troubleshooting

Module Fault LED

Possible causes:

• ModuleBus communication error
• Hardware configuration mismatch
• Internal diagnostics failure

Incorrect Output Current

Check:

• Output range configuration
• Loop resistance (maximum 850 Ω)
• External 24 V supply
• Wiring polarity

6. Frequently Asked Questions (FAQ)

Q1. Can the AO801 be replaced while the system is energized?

Although some S800 I/O configurations support online replacement, replacement procedures depend on your controller architecture and plant maintenance policy. For most installations, ABB recommends replacing the module during a planned shutdown to eliminate the risk of process interruption.

Q2. Does the AO801 support HART communication?

No. The AO801 provides standard 0–20 mA and 4–20 mA analog outputs only and does not support HART communication. Applications requiring HART functionality should use compatible ABB HART-capable analog output modules instead.

Q3. What field devices can the AO801 control?

Typical applications include:

• Control valves
• Variable frequency drives (VFDs)
• I/P converters
• Valve positioners
• Process controllers
• Analog indicators and recorders

Q4. Will replacing the AO801 affect the PLC application program?

No. The control logic remains stored in the AC 800M controller. However, verify hardware configuration, channel assignments, and scaling parameters after replacement before returning the process to service.

Q5. Is the AO801 still available?

Yes. Although it has been on the market for many years, the AO801 remains widely available through industrial automation spare-parts suppliers as New Original (New Surplus) and professionally tested refurbished inventory.

Q6. Why should I verify loop resistance before commissioning?

The AO801 is rated for output loads up to 850 Ω. Excessive loop resistance can prevent the module from reaching the commanded output current, resulting in inaccurate control signals or device faults. Confirm cable length, field device impedance, and power supply capacity during commissioning.