Protocol Point Summary; Register Mapping; Table 4. Chiller Data Points - Daikin McQuay MicroTech III Manual

Protocol Point Summary

The following section provides a summary of Modbus properties available from the MicroTech III Chiller Unit
Controller. Tables 4-8 contains the complete list of chiller, circuit, compressor, pump, and miscellaneous data points
respectively. The items shown in boldface represent the minimum integration properties (as identified previously in
Table 3.)

Register Mapping

The Modbus Communication Module supports zero-based addressing. For example, holding register 40002 is addressed
as 0001 in a Modbus message. The following tables assume 4xxxx addressing. For example, 1 will be holding register
40001.

Table 4. Chiller Data Points

Network Control Property
Chiller Local/Remote
Chiller Enable Output
Run Enabled
Chiller Capacity Limited
Alarm Digital Output
Evaporator Flow Switch Status
Chiller On/Off
*Chiller Enable Setpoint (4)
*Clear Alarms – Network (14)
Chiller Mode Output
Active Setpoint
*Actual Capacity (3)
Active Capacity Limit Output
*Chiller Status (Chiller Run Mode) (1)
*Evaporator Entering Fluid Temperature (5)
*Evaporator Leaving Fluid Temperature (6)
Outdoor Air Temperature
Chiller Current
Warning Alarm Index
Problem Alarm Index
Fault Alarm Index
10
Holding
Read/
Register
Page
Write
(4xxxx)
21 1 R
21 2 R
27 3 R
4
20 R
19 5 R
25 6 R
22 8 R
21 9 R/W
22 10 R/W
21 11 R
19 12 R
19 13 R
19 14 R
22 15 R
16
25 R
25 17 R
26 24 R
20 25 R
27 28 R
27 29 R
26 30 R
Description
0=Remote, 1=Local
0=Disable, 1=Enable
0=Off 1= RunAllowed
0=Not Limited, 1=Limited
0=No Alarm, 1=Alarm
0=No Flow, 1=Flow
0=Off, 1=On
0=Disable, 1=Enable, 2=Null
0=Normal, 1=Clear Alarms, 2=Null
1=Ice, 2=Cool, 3=Heat, 4=Cool/Heat Recovery, 5=Defrost
15.08°F to 149.9°F (-9.4°C to 65.5°C)
0 - 100%
0 - 100%
1=Off, 2=Start, 3=Run, 4=Pre Shutdown, 5=Service
-40-230°F (-40-110°C)
-40-230°F (-40-110°C)
-40-230°F (-40-110°C)
0-10,000 Amps
0=No Alarms
5=Evaporator pump maintenance
7=Compressor maintenance Circuit #n
8=Bad setpoint override input
9=Bad demand limit input
11=Unit power restore
12=Circuit failed pumpdown
13=External Event
0=No Alarms
64=RESTART DELAYED-Power Loss While Running Circuit #n
65=START INHIBITED - Ambient Temperature Low
67=INHIBIT LOAD – Condenser Pressure High Circuit #n
69=UNLOAD – Condenser Pressure High Circuit #n
76=INHIBIT LOAD - Evaporator Pressure Low Circuit #n
78=UNLOAD - Evaporator Pressure Low Circuit #n
0=No Alarms
127=COMP SHUTDOWN–Low pressure ratio #n
128=COMP SHUTDOWN-Outside Air Temp Sensor Fault
135=COMP SHUTDOWN–Motor Temp High Circuit #n
136=COMP SHUTDOWN–Motor Temp Sensor Fault #n
142=COMP SHUTDOWN-Condenser Pressure Sensor Fault #n
145=COMP SHUTDOWN-Condenser Pressure High #n,
147=COMP SHUTDOWN-Discharge Temp Sensor Fault #n
148=COMP SHUTDOWN-Discharge Temp High #n
150=UNIT SHUTDOWN-Evaporator Water Flow Loss
151=UNIT SHUTDOWN–Evaporator Leaving Water Temp Low
(Freeze)
153=COMP SHUTDOWN-Evaporator Pressure Low #n,
ED 15121