System Architecture; Modbus Communication - Unit - Daikin Pathfinder AWV Series Installation, Operation And Maintenance Manual

System Architecture

The overall controls architecture uses the following:
• One MicroTech ® III unit controller
• I/O extension modules (sometimes referred to as
"controllers") as needed depending on the configuration
of the unit
• Up to three BAS interface modules as needed based on
installed options
Figure 60: System Architecture Schematic
BAS Comm BAS Comm BAS Comm
Interface Interface Interface
Module Module Module
NOTE: Graphic shows typical chiller controller arrangement; individual chiller configurations will be as ordered.
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Unit Controller
Peripheral Bus
Alarm/Limit Circuit 1
I/O Extension I/O Extension
DC Fan Controller
43

Modbus Communication - Unit

The unit controller (UC) communicates to the compressor
VFD's and the EXV modules via the Modbus RTU connection
on the controller itself. Communication to the VFD's and EVAP
EXV MODULE is required for operation in all configurations.
Communication to ECON EXV MODULE is required only if the
chiller is configured with economizers.
Compressor
VFD 1
Modbus
Evap EXV
Circuit 2 RapidRestore®
I/O Extension I/O Extension
DC
Fan
Modbus
IOM 1242-2 • PATHFINDER
C o
onTroller
Compressor
VFD 2
Economizer EXV
Module Module
...
DC DC DC
Fan Fan Fan
MODEL AWV CHILLERS
®
peraTIon