Honeywell PCD3.W315 – Communication Interface Module for Saia PCD3 Controllers

The Honeywell (Saia Burgess Controls) PCD3.W315 is part of the PCD3 communication expansion family, designed to add an extra serial channel to PCD3 automation CPUs. In many cases, engineers use this module to connect field devices like VFDs, heat meters, or room controllers on a serial bus, typically for Modbus RTU or vendor-specific protocols supported by the PCD3 platform. From my experience, it’s a straightforward way to scale communications without changing the main CPU or redesigning the cabinet.

One thing I appreciate is how it integrates into the existing PCD3 base without the need for separate power. You might notice that projects benefit most when the controller needs one more dedicated serial line for a noisy network segment or when separating critical device chains improves troubleshooting and uptime. A systems integrator recently told us they slotted a PCD3.W315 into an existing PCD3.M controller to bring a set of energy meters online—no CPU swap, minimal wiring changes, and commissioning stayed on schedule.

Our Order Process & Guarantees

• – Warranty period: 365 days from delivery

• – Lead time: typically 1 week if in stock; no more than one month at the latest

• – Payment terms: 50% advance payment; full payment before delivery

– Express options: FedEx, UPS, DHL

Key Features

• Serial communication expansion – Adds an additional serial channel to the PCD3 controller, commonly used for Modbus RTU or vendor-specific protocols.
• Backplane-powered – No separate power supply required; the module draws power from the PCD3 base for clean, reliable installation.
• Compact, single-slot footprint – Saves space in crowded HVAC and OEM panels, fitting into standard PCD3 bases on DIN rail.
• Status indication for diagnostics – Front indicators (typical on PCD3 interface modules) help verify port activity during commissioning.
• Ideal for building automation – Frequently used to connect drives, meters, and room controllers in retrofit or expansion projects.

Technical Specifications

Related / Supporting Products

• PCD3.Mxxx CPUs – Main controllers that host the PCD3.W315 and execute the application.
• PCD3.W3xx family – Similar serial interface variants offering different port types or isolation; choose per device protocol and wiring needs.
• PCD3.Bxxx / PCD3.Axxx – Digital and analog I/O modules to expand point counts alongside the communication module.
• PCD3.Cxxx bases – Mounting bases/terminal blocks for PCD3 modules on DIN rail.
• Saia HMIs (PCD7 series) – Local operator panels commonly paired with PCD3 installations.

Installation & Maintenance

• Cabinet & mounting – Install on an EN 60715 DIN rail with a PCD3 base. Allow ventilation space above and below the module; avoid mounting near high-heat sources.
• Wiring practice – Use twisted-pair, shielded cable for serial networks, with proper termination and biasing where required by the device chain. Separate communication wiring from power conductors.
• Grounding & EMC – Bond shields at one side (typically the controller side) and maintain a clean cabinet ground to reduce noise on long runs.
• Safety – Power down the controller before inserting or removing modules. Verify correct addressing and port parameters in the controller program before energizing the bus.
• Routine maintenance – Periodically check terminal tightness, cable integrity, and network termination. Keep the module free of dust; review controller firmware/drivers periodically and update if required by the project.

Quality & Certifications

• CE compliant; RoHS compliant
• UL recognition is typical for the PCD3 family (varies by exact module/version)
• Manufactured within Honeywell’s quality system (ISO 9001 at corporate level)
• Warranty: 365 days