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Introduction
This document contains the necessary information to incorporate a MicroTech
®
III Chiller Unit Controller from McQuay
International into your Building Automation System (BAS). It includes all necessary Modbus
®
variables and
corresponding MicroTech III Chiller Unit Controller data points. Modbus terms and principles are not defined. Refer to
the appropriate specifications for definitions and details.
Chiller Models
The following table lists the model designators of McQuay International Chiller units and the corresponding description.
AWS Air-Cooled World Screw
Controller Data Points
The MicroTech III Chiller Unit Controller contains data points or unit variables that are accessible from two different
user interfaces: the unit keypad/display or a Modbus serial network. Not all points are accessible from each interface.
This manual lists all important data points and the corresponding network path for each applicable interface. Refer to the
applicable Operation Manual for keypad/display details.
NOTICE
The MicroTech III Chiller Unit Controller maps additional Modbus registers that are not
included in this document. These registers are for internal use only. Please contact McQuay
Controls Customer Support at 866-462-7829 for assistance with Modbus integration.