IM 743-1
5
General Information
This manual contains the information you need to install a MicroTech II® Modbus® Communication
Module and integrate it into the network.
!
WARNING
Electric shock hazard. Can cause personal injury or equipment damage.
This equipment must be properly grounded. Only personnel knowledgeable in the operation of the
equipment being controlled must perform connections and service to the MicroTech II Chiller
Unit Controller.
!
CAUTION
Static sensitive components. Can cause equipment damage.
Discharge any static electrical charge by touching the bare metal inside the control panel before
performing any service work. Never unplug cables, circuit board terminal blocks, or power plugs
while power is applied to the panel.
NOTICE
This equipment generates, uses and can radiate radio frequency energy and, if not installed and
used in accordance with this instruction manual, may cause interference to radio communications.
It has been tested and found to comply with the limits for a Class A digital device, pursuant to part
15 of the FCC rules. These limits are designed to provide reasonable protection against harmful
interference when the equipment is operated in a commercial environment. Operation of this
equipment in a residential area is likely to cause harmful interference in which case the user will
be required to correct the interference at his or her own expense.
McQuay International
disclaims any liability resulting from any interference or for the correction thereof.
Description
A Modbus Communication Module provides the interface between a MicroTech II Chiller Unit
Controller and a Modbus network. It translates the Modbus variables used on the network to the
variables used in the unit controller and vice versa.
The Modbus Communication Module is a printed circuit board that plugs into the MicroTech II
Chiller Unit Controller. Figure 1 is an outline drawing of the printed circuit board.
Figure 1. Modbus Communication Module – RS-485 (Component Side)
Application
A Modbus Communication Module connects the MicroTech II Chiller Unit Controller to a network
using the Modbus protocol. It is the interface between the network and the unit controller. The
Modbus Communication Module translates the Modbus protocol variables into the native data
formats of the unit controller.
