MPC and LON Controls

MPC Controller Overview

The MultiProtoCol (MPC) Heat Pump controller is designed to allow the integration of water source heat pump equipment into DDC systems. The MPC Controller has the ability to communicate through a choice of three widely used protocols: BACnet MS/TP, Johnson Controls N2, and Modbus. The protocol of choice for the particular system is selected by simply configuring DIP switches on the MPC Controller. This flexibility allows one controller, the MPC, to be used in a multitude of buildings which use any of these three common protocols.

The MPC serves as a node of information processing between the heat pump and the DDC network. See Figure below. The MPC commands the heat pump to heat and cool based upon sensor inputs. The MPC then monitors operation of the heat pump and communicates the operating parameters to the DDC network. The MPC will always work in conjunction with a CXM or DXM controller, which also resides in the heat pump control box. The MPC has factory pre-loaded application software which allows optimal control of the heat pump equipment. The MPC can run in stand-alone operation as well as with the DDC network. Therefore, when the heat pump arrives at the jobsite with the factory installed MPC Controller, the heat pump is ready to run stand-alone and then can be connected to the DDC network at any time.

Typical System for MPC Controller Water-to-Air Heat Pump

FEATURES & BENEFITS

Multi-Protocol communications provides DDC
system flexibility.

• Supports native BACnet MS/TP communications (the ASHRAE standard protocol for interoperability).
• Supports Johnson Controls N2 communications (for integration into Johnson Controls Metasys DDC systems).
• Supports Modbus communications for integration into Modbus DDC networks.
• Four baud rate levels offer flexible communications speeds of 9600, 19.2k, 38.4k, or 76.8k baud.
• Employs a 16-bit bus Hitachi processor with 512kB RAM and 1024kB Flash Memory which allows, if needed, MPC programs to be upgraded and easily downloaded in the field.
• Removable field wiring connectors for ease of field service.
• Engineered for quality and reliability
• Enables building operators to easily upgrade firmware in the future.

LON Controller Overview

The LON controller is an interoperable, LONMark® compliant controller. The LON controller has factory loaded application specific software which allows optimal control of our water source heat pumps in buildings which require DDC control.

The ASW01, ASW02, and ASW03 sensors are digital wall mounted temperature sensors to be used with the LON controller. The LON controller and ASW digital wall sensors communicate via Sensor Link (S-Link) communications protocol. S-Link is a simple two wire communication protocol which provides power to the ASW wall sensor as well as transmits information between the ASW wall sensor and the LON controller. The S-Link protocol is NOT polarity sensitive and does NOT require shielded cable.

The ASW wall sensors have an optional wiring connection which allows access to the LON network via a LON jack on the left side of each ASW wall sensor.

The LON controller can function in either stand-alone mode, or as part of a LONWorks® FTT-10 Free Topology communications network. When connected to a network, the operator can monitor LON controller performance and edit operational values.

Typical Heat Pump System Diagram for LON Controller

LON Controller

• Uses LONMark® HVAC profiles for interoperability.
• Capability to function in stand-alone mode or as part of a LONWorks® FTT-10 Free Topology communications network.
• Proportional Plus Integral (PI) control for heating and cooling.
• Protective hinged covers provide easy access to field wiring terminals.
• Onboard LED indication without cover removal.
• Occupied/Unoccupied modes of operation.
• Intermittent or continuous fan operation.
• Non-polarized wiring between LON controller and wall sensors.
• Programability provides for custom applications.

ASW Digital Wall Sensors

• Contemporary, low-profile design.
• Digital zone temperature indication (selectable for 0.1 or 1 degree display resolution of °F or °C).
• Accepts virtually any wiring type including unshielded pairs without termination resistors.
• Separate wiring subbase and electronics.
• Occupancy override push-button on ASW02 and ASW03 wall sensors allows occupants to switch to timed Occupied Mode for after hours operation.