22
ED 15121
Chiller Mode Setpoint - Network
Keypad Menu Path
No Keypad Equivalent
This read/write holding register is used to change the operating mode of the chiller. The default is Null(0). A value of
Null will cause the chiller to run in the Cool mode provided that nothing else is writing to this point. This register is
ignored by the chiller application if Chiller Local/Remote is set to Local. It also only applies when Available Modes is
set to Cool/Ice w/Glycol. Available Modes can also be found on the keypad. Only Ice and Cool modes are supported.
If any other mode is written, the chiller will be set to Cool mode.
Data Type
Holding Register
Measurement
Units
Valid Range
RW Holding Register
34
HVAC Mode
N/A
0=Null
1=Ice
2=Cool
3=Heat
4=Cool/Heat Recovery
Chiller Model
Keypad Menu Path
No Keypad Equivalent
This read only holding register indicates the model of the chiller.
Data Type
Holding Register
Measurement
Units
Valid Range
RO Holding Register
317
Chiller Model
N/A
TBD
Chiller On/Off
Keypad Menu Path
No Keypad Equivalent
This read only holding register indicates the current state of the chiller. The OFF state is represented by state = FALSE
and value = 0. The other discrete states are represented by state = TRUE and value > 0.
Data Type
Holding Register
Measurement
Units
Valid Range
RO Holding Register
8
Chiller State
N/A
0=Off
1=On
Chiller Status
Keypad Menu Path
No Keypad Equivalent
This read only holding register indicates the unit status of the chiller.
Data Type
Holding Register
Measurement
Units
Valid Range
RO Holding Register
15
Chiller State
N/A
1=Off
2=Start
3=Run
4=Pre Shutdown
5=Service
Clear Alarms - Network
Keypad Menu Path
No Keypad Equivalent
This read/write holding register clears all active alarms. Many alarms clear automatically (see MicroTech III Chiller Unit
Controller Operation Manual for details). The following are the only alarms that can be cleared from the network:
•
UNIT SHUTDOWN - Evaporator Water Flow Loss
•
UNIT SHUTDOWN–Evaporator Leaving Water Temp Low (Freeze)
•
CIRCUIT SHUTDOWN – Evaporator 1 Freeze Protection
•
CIRCUIT SHUTDOWN – Evaporator 2 Freeze Protection
The default is Null, which will cause Normal to be used provided nothing else is writing to this point. This register is
ignored by the chiller application if Chiller Local/Remote is set to Local.
Data Type
Holding Register
Measurement
Units
Valid Range
RW Holding Register
10
NA N/A
0=Normal
1=Clear Alarm
2=Null
