Product Details
The Honeywell UL08AO-ISO-D25, also cataloged as the UL08AO-ISO-D25 Analog Output Module, operates as a dedicated hardware component for driving 4-20 mA current loops within Honeywell process control platforms.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | UL08AO-ISO-D25 |
| Brand | Honeywell |
| Origin | USA |
| Weight | 0.59 kg |
| Dimensions | 355 mm x 158 mm x 87 mm |
| Operating Temp | -20 deg C to +60 deg C |
| Power Consumption | 24 VDC nominal (12.5 W maximum) |
| Output Channels | 8 analog current outputs (4-20 mA) |
| Isolation Type | Channel-to-channel galvanic and optical isolation |
4-20 mA HART Loop Protocol & Channel-to-Channel Isolation
The UL08AO-ISO-D25 converts digital control values from the primary controller backplane into 8 isolated 4-20 mA current outputs to drive actuators, positioners, and control valves. Individual channel-to-channel galvanic and optical isolation prevents field ground loops and suppresses electrical transients from propagating back to system logic boards. Integrated short-circuit protection limits output fault current per channel, while real-time LED diagnostics provide immediate visual verification of loop current integrity and open-circuit status.
Frequently Asked Questions
Q: What happens to the 4-20 mA outputs if the module loses backplane bus communication with the primary controller?
A: Upon detection of a backplane communication timeout, each output channel transitions to a user-configured fail-safe condition (either hold-last-value or zero-scale 4 mA output) to prevent unpredictable actuator motion.
Q: Can an individual 4-20 mA output channel withstand a sustained short circuit on its field terminals?
A: Yes. Each channel features internal active current limiting hardware that maintains signal protection during an accidental short circuit without causing thermal damage or affecting adjacent channel outputs.
Field Installation Guidelines
- DIN-Rail Mounting: Snap the module secure housing onto a standard 35 mm DIN rail, ensuring top and bottom metal retention clips lock fully into position.
- Wiring Clearance: Maintain a minimum 50 mm wiring duct separation between 4-20 mA analog output field cables and high-voltage AC power cables to prevent electromagnetic noise induction.
- Shield Termination: Terminate field cable drain wires at the designated cabinet grounding bar using a single-point connection to eliminate circulating ground loop currents.
- Diagnostic Check: Verify that all channel status LED indicators illuminate green upon applying 24 VDC auxiliary loop power prior to putting the outputs into active control modes.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
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