AMX VST Instruction Manual page 26

ViewStat Programming Protocol
Thermostat Action Commands (Cont.)
Command
MODE
Thermostat Mode Of Operation
FAN
Hvac Fan Operation
22
Description
This command dictates what equipment the thermostat will turn on/off to
control temperature. In the HEAT mode, only the heating equipment will
be used, in the COOL mode, only the cooling equipment will be used.
When the thermostat has been configured to operate a heat pump (this is
a DIP switch configuration on the thermostat), Emergency Heat (EMHT)
mode is available. In the Emergency Heat mode, only the back-up heat
source is used.
When a humidity control sensor (optional accessory) is wired to the ther-
mostat it becomes a humidity controller instead of a temperature control-
ler. Operating as a humidity controller, HUMID mode will operate the
humidifier only, DEHUM mode operates the dehumidification equipment
only.
In the AUTO mode, either the heating or cooling equipment will be used, or
if acting as a humidity controller, either the humidification or dehumidifica-
tion equipment will be used. Care must be exercised in the selection of
AUTO mode. The AUTO mode should not be set during extremely high or
extremely low outdoor temperature conditions. Operating the cooling
equipment when the outdoor temperature is low (i.e. below 50°F) can be
damaging to the equipment as can operating the heating equipment when
the outdoor temperature is too high. Consult with HVAC installers for safe
operating conditions.
The OFF mode effects equipment operation only. When OFF, the thermo-
stat does not control temperature or humidity. OFF mode should not be set
when it is possible to encounter freezing outdoor temperatures to avoid
water pipe freezing.
Syntax:
SN[address] MODE=HEAT, COOL, EMHT, HUMID, DEHUM, AUTO
or OFF
• (Alternatively H may be used for Heat, C for Cool, A for Auto or E for
EMHT)
Reply Format:
SN[address] M=HEAT, COOL, E, HUMID, DEHUM, AUTO or OFF
HVAC system blowers run automatically when the heating or cooling sys-
tem is operating. They can also be turned on to run continuously to pro-
vide air movement and/or air filtration. The Fan button on the thermostat is
used to run the system blower continuously or to run automatically. This
command performs the same function as the thermostat Fan button.
Syntax:
SN[address] FAN=ON or AUTO
• (Alternatively A can be used for Auto)
Reply Format:
SN[address] F=ON or AUTO
ViewStat Communicating Thermostat - Programming Protocol Reference Guide