Honeywell 900B01-0301 Analog Output Module Overview

The Honeywell 900B01-0301 is a 4 channel analog output module. It belongs to the 900 Series from Honeywell. This module provides isolated current outputs from 0 to 21.8 mA. Users can scale each output to any span within this range. The 900B01-0301 supports failsafe state configuration for predictable operation. A green blinking LED indicates when the module is being scanned.

Technical Specifications of 900B01-0301

The Honeywell 900B01-0301 has 4 isolated outputs per module. Current range is selectable from 0 to 21.8 mA. Maximum load resistance is 750 ohms. Accuracy reaches 0.1% of full scale at reference conditions. D/A resolution is 12 bits for precise control.

Galvanic isolation is 500 VDC between channels. Isolation from logic power is 600 VDC. Minimum current sensing requires more than 3.5 mA per output. Outputs update synchronous with IOM scan time. The minimum scan time is 500 milliseconds.

Calibration data stores in non-volatile memory. Redundant factory calibration with automatic rejection of bad versions. Diagnostics monitor factory calibration and configuration. The module also checks the +24 VDC power supply. Output verification feedback confirms current flow to the controller.

Users can configure failsafe behavior for the 900B01-0301. Two failsafe options are available. Hold last value keeps the previous output state. Failsafe value applies a user-specified output. The slew rate function block supports user scan rates. Slew rate limits the milliamp change per execution cycle.

Maximum modules per rack is 10 units. Up to 12 modules work with temperature de-rating. A red status LED lights when module or channel diagnostics exist. The module does not include any batteries. WEEE Category is 5 for small equipment.

Installation Guidelines for Honeywell 900B01-0301

Mount the 900B01-0301 in a Honeywell 900 Series rack. Align the module with the correct slot position. Push firmly until the connectors engage fully. Secure the module with the locking latch at the bottom. Connect field wiring to the removable terminal block.

Use shielded twisted pair cables for each analog output. Connect the shield to ground at the module end only. Do not run output wires near high voltage cables. Leave at least 10 cm separation from AC power lines. Do not apply more than 30 VDC to any output terminal.

Configure the output range using Honeywell Control Builder software. Set each channel to 0-20 mA or 4-20 mA as needed. Define the failsafe behavior for every output. Download the configuration to the controller. Verify the green LED blinks to confirm scanning.

Package Contents of 900B01-0301

Your shipment includes these items:

One Honeywell 900B01-0301 analog output module

One removable terminal block for field wiring

One module locking latch (pre-installed)

One installation instruction sheet

Four output channel labels for identification

The package does not include the backplane rack. You must purchase the rack separately. No configuration software is provided with this module.

Frequently Asked Questions about 900B01-0301

1. What is the slew rate function on 900B01-0301?

Slew rate limits how fast the Honeywell 900B01-0301 changes output current. You set the maximum change per second in milliamp. This protects valves from sudden position changes. The function block executes each scan cycle.

2. Can I mix 0-20mA and 4-20mA on the same module?

Yes, each channel on 900B01-0301 is independently configurable. Set channel 1 for 0-20 mA and channel 2 for 4-20 mA. All four channels share the same module but different scales. Use Control Builder software to assign per-channel ranges.

3. What does the red LED mean on 900B01-0301?

A red LED on Honeywell 900B01-0301 indicates a diagnostic condition. This could be a calibration error or configuration fault. It may also signal a lost communication link. Check the controller for specific error codes.

4. How does failsafe work on this output module?

The 900B01-0301 supports two failsafe modes. Hold Last Value keeps the last good output. Failsafe Value applies a preset safe current. This protects equipment when communication with the controller fails.

5. What is the maximum number of 900B01-0301 modules per rack?

You can install up to 10 Honeywell 900B01-0301 modules per rack. For 12 modules, reduce the ambient temperature by 5°C. Check the product de-rating curve for exact limits. Exceeding these limits may cause overheating.

Compatibility and Application Notes

The Honeywell 900B01-0301 works with Honeywell 900 Series controllers. It suits valve positioning and actuator control applications. Use it for variable speed drives and chart recorders. The 12-bit resolution provides 4096 steps over 0-20 mA range. This module is not RoHS 2 compliant as a spare part. For new installations, order the updated version. The HS code for customs is 85389000. Dispose of this module according to local WEEE regulations.