6. Programming Notes
DCM014A51
Quick User Guide
9
6. Programming Notes
6.1 iTM Control Logic and The Related BACnet® Points
With the BACnet® server option, the iTM's advanced control logic can be accessed directly through the BACnet®
points.
The following figure shows which BACnet® points are linked to the iTM logic.
6.2 Setpoints
Each indoor unit group address can be assigned independent cooling and heating setpoints for the occupied and
unoccupied periods. “Occ Cooling Setpoint – Occ Heating Setpoint – Unocc Cooling Setpoint – Unocc Heating
Setpoint”.
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The Occupied Setpoint can be set via the schedule (iTM or BMS) or manually from the remote controller,
iTM or BMS. The setpoint stored in the indoor unit will be based upon the last command (last setpoint)
received since the indoor unit does not recognized priority arrays.
•
Setpoints set by the BMS are also updated in the iTM and setpoints set at the iTM are updated to
the BMS.
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The Unoccupied setpoint can be set via the schedule (iTM or BMS) or manually from the iTM or BMS. The
setback should be enabled at the iTM during its commissioning. The BMS can monitor and adjust the
unoccupied setpoint if it is set at the iTM.
6.3 Auto-changeover
“Enable ITM Auto changeover operation” point allows the BMS to enable/disable all the Changeover groups
simultaneously when the Changeover Groups are configured in the iTM. Review
iTM BACnet® Server Design
Guide – Part 1 iTM
, Auto-Changeover section.
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The iTM can handle the cool/heat auto-changeover for the changeover groups, which consists of all
indoor units in Heat Pump systems, Heat Recovery systems or under BS units in Heat Recovery system.
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The changeover method selected in the iTM is configured from one of the following: Fixed, Average,
Individual, and Vote. Refer to
iTM BACnet® Server Design Guide
for more details.
•
Different changeover options can be select for each Changeover group.
