Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 900B01-0101 |
| Manufacturer | Honeywell International Inc. |
| Product Type | Analog Output Module (AO), 4-channel, galvanically isolated |
| Series / Platform | Honeywell ControlEdge HC900 / 900 Series hybrid control system |
| Number of Outputs | 4 individually isolated channels |
| Output Signal Range | 0 to 21.8 mA per channel, user-scalable (typically configured 4-20 mA) |
| Accuracy | ±0.1% of full scale under reference conditions |
| D/A Resolution | 12 bits |
| Maximum Load Resistance | 750 Ω per channel |
| Galvanic Isolation | 500 VDC channel-to-channel; 600 VDC field-to-logic |
| Minimum Detectable Current | > 3.5 mA per output for output-current verification |
| Failsafe Behaviour | User-specified failsafe value per channel on loss of communication |
| Rate Control | User-specified rate-of-change limit and synchronous output updates |
| Backplane Power Consumption | 5 VDC at 40 mA maximum; 24 VDC at 200 mA maximum |
| Diagnostics | Factory and field calibration monitoring, configuration checks, 24 VDC supply supervision, output current feedback |
| Calibration Storage | Non-volatile memory with redundant factory calibration and per-channel field calibration |
| Modules per Rack | Up to 10 standard, up to 12 with temperature de-rating |
| Operating Temperature | 0 °C to +60 °C (storage −40 °C to +85 °C) |
| Relative Humidity | 5% to 95% non-condensing |
| Dimensions (H × W × D) | 137 × 35.6 × 137.16 mm |
| Weight | Approx. 0.397 kg |
| Certifications | CE, UL listed for industrial control equipment, RoHS compliant |
Main Features and Advantages
True per-channel isolation: The Honeywell 900B01-0101 isolates all four outputs from each other and from the logic side, which eliminates the ground loops and cross-talk that plague non-isolated output cards. In practical terms, a technician can break a loop, short a cable or replace an actuator on channel 3 without disturbing channels 1, 2 and 4, and without risking the controller backplane. This is especially valuable in plants where several control valves share a common pipe rack, a common cable tray and a common earthing system.Output verification that closes the loop: Many analog output cards are “write-only”: the controller sends a value and hopes the field device received it. The Honeywell 900B01-0101 senses the actual current flowing in each loop and reports it back, so the control strategy can raise an alarm when a valve coil opens, a loop wire breaks or an actuator input fails. Combined with continuous monitoring of calibration, configuration and the 24 VDC field supply, this turns a silent failure into a visible, diagnosable event.Predictable behaviour under fault conditions: Every channel of the Honeywell 900B01-0101 can be assigned its own failsafe value, so when communication with the controller is interrupted the outputs move to a defined safe position rather than freezing at the last command or drifting to an unknown level. Programmable rate-of-change limits prevent a setpoint step from slamming a valve or jerking a damper, and synchronous output updates guarantee that all four channels change on the same controller scan, which matters for ratio and cascade strategies.Service-friendly by design: Factory calibration is stored redundantly, invalid versions are rejected automatically, and individual channels can be field-calibrated with the results retained through power loss. The Honeywell 900B01-0101 supports insertion and removal under power in an HC900 rack, and dual status LEDs give instant front-panel confirmation: a blinking green LED indicates normal scanning, while a red LED flags a module or channel fault. With up to ten modules per rack and rack expansion via I/O scanners, output capacity grows with the process rather than forcing a platform change.
