Description
Honeywell MC-PAIH03 | 16-Channel HLAI I/O Processor
Product Overview
The Honeywell MC-PAIH03 is a dedicated High-Level Analog Input I/O Processor used to acquire process analog signals within Honeywell process-control architectures. Honeywell’s technical documentation identifies it specifically as a 16-input High-Level Analog Input Processor, rather than a general-purpose PLC analog card.
This distinction matters when sourcing a legacy spare. The module sits inside a defined Honeywell I/O architecture, so a visually similar analog input card is not automatically a valid substitute. The MC-PAIH03 model designation also has a specific coating meaning: Honeywell documentation states that the high-level analog input processor is available as the conformally coated MC-PAIH03, with no uncoated equivalent under that model number.
The commonly associated CE-compliant assembly number is 51304754-150. Honeywell documentation lists MC-PAIH03 as the HLAI IOP in the HPM High-Performance Process Manager I/O equipment set.
For procurement, keep MC-PAIH03 and 51304754-150 together in the search record rather than relying on the model number alone.

MC-PAIH03
Key Technical Specifications
- Model: MC-
- Function: High-Level Analog Input Processor
- Channel count: 16 differential analog input channels
- Input type: Voltage and current
- Transmitter support: 2-wire or self-powered transmitters
- Published input ranges: 0–5 V, 1–5 V, 0.4–2 V, and 4–20 mA through 250 Ω
- A/D converter: 16-bit converter, with 14 bits used according to the published Honeywell specification
- Common-mode rejection: 70 dB, DC to 60 Hz, with specified 500 Ω source imbalance
- Normal-mode rejection: 32 dB at 60 Hz
- Normal-mode filtering: Single-pole RC, −3 dB at 1 Hz
- Maximum differential input without damage: ±30 V
- Channel-to-channel crosstalk: 60 dB, DC to 60 Hz
- Voltage-input impedance: Greater than 10 MΩ powered
- Input scan rate: 4 samples/second/channel, with all channels sampled within a 250 ms window
- Published hardware accuracy: ±0.075% full scale at approximately 23.5°C ±2°C; ±0.15% full scale over 0–50°C
- Common-mode voltage range: −6 to +5 V peak, DC to 60 Hz
- Assembly designation: MC-
- CE-compliant assembly: 51304754-150
The electrical characteristics above are taken from Honeywell Process Manager I/O technical material reproduced in available documentation.
Global Sourcing & Incoming-Test SOP
For a legacy Honeywell I/O processor, identification comes before power-up.
Recommended incoming inspection:
- Photograph the complete nameplate before unpacking further.
- Record , assembly/part number, hardware revision and any additional board identifiers.
- Confirm whether the supplied unit is actually 51304754-150 or another 51304754-x suffix.
- Inspect the conformal coating for cracking, contamination, peeling or evidence of chemical exposure.
- Inspect edge connectors, terminal interfaces and mounting points for mechanical damage.
- Check for corrosion, moisture residue, overheated components, repaired PCB traces or replaced components.
- Compare the hardware revision against the revision installed in the customer’s Honeywell system.
- Verify the associated field termination assembly before installation. Honeywell documentation lists multiple compatible HLAI termination arrangements, so the IOP should not be treated as an isolated generic analog card.
- If functional testing is required, perform it in an appropriate Honeywell-compatible test environment rather than applying uncontrolled field power.
- Simulate known voltage/current inputs and verify channel acquisition against the expected engineering values.
- Record diagnostics, channel behavior and revision information in the incoming inspection report.
- Package the board in ESD-safe material for storage or shipment.
Important: These are recommended procurement and incoming-test procedures. They do not mean that the particular MC- unit being sourced has been electrically tested.
Field Engineer’s Pitfall Guide
1. Do not confuse MC- with a generic 16-channel analog input card.
The 16-channel count is only part of the story. MC- is an HLAI IOP designed for a specific Honeywell control-system architecture. Honeywell’s own documentation categorizes it as an HLAI processor within the Process Manager I/O system.
2. Check the complete part number and hardware revision.
This is particularly important for replacement work. Honeywell issued a notification concerning MC- / 51304754-176 and Process Manager compatibility, specifically identifying a hardware-revision dependency. That does not mean every MC- carries the 51304754-176 assembly number; it means the installed part’s exact suffix and revision should be verified rather than treating all MC- listings as interchangeable.
3. Verify the field termination arrangement before ordering.
The HLAI processor can be associated with different Honeywell FTA configurations. A correct IOP with the wrong termination arrangement can still result in an unusable replacement. Match the existing system documentation, FTA model and wiring before approving the purchase.
FAQ
Q: What is the Honeywell MC-?
A: It is a Honeywell High-Level Analog Input Processor with 16 differential analog input channels, intended for Honeywell process-control I/O architectures.
Q: What is the commonly associated part number?
A: The CE-compliant coated assembly is listed as 51304754-150 in Honeywell HPM equipment documentation. Always verify the suffix on the physical unit because other 51304754 variants also exist.
Q: What signals can MC- accept?
A: Published Honeywell specifications list 0–5 V, 1–5 V, 0.4–2 V and 4–20 mA through a 250 Ω input arrangement. The processor supports voltage/current inputs from 2-wire or self-powered transmitters.
Q: Is MC- the same as a PLC analog input module?
A: Not in procurement terms. It is an I/O processor designed for Honeywell’s Process Manager/HPM control architecture. Treating it as a generic PLC analog card can lead to incorrect compatibility assumptions.
Q: Is MC- conformally coated?
A: Yes. Honeywell documentation identifies the MC model as the conformally coated version and specifically lists MC- as the coated HLAI processor.
Q: Can any MC- be installed as a direct replacement?
A: Do not assume that. Confirm the complete assembly number, hardware revision, installed system, FTA configuration and applicable Honeywell compatibility documentation before installation.
Q: What should I request from a surplus supplier?
A: Request clear photographs of the nameplate and PCB revision markings, the exact assembly number, hardware revision, coating condition and any available powered-test report. If the seller cannot provide functional evidence, classify the unit commercially as untested rather than assuming it is operational.


