Part 2. Functional Specifications
28 Design Guide DCM014A51
2. The BACnet Server in iTM sends the new PV to Management Point in iTM. The BACnet Server in
iTM then starts a 10 minute timer.
3. If the value in Management Point is changed (i.e., the indoor unit accepted the new value and
sent back the new status to iTM), the Management Point in iTM sends the new value to the
BACnet Server in iTM. The BACnet Server in iTM updates the PV and resets the 10 minute
timer.
4. If the value in Management Point is not changed (i.e., the indoor unit did not accept the new
value and did not update the status to iTM) nothing happens. When the 10 minute timer
expires, the BACnet Server in iTM resets to the previous PV.
EXAMPLE 1 – Cool SP Max
Unocc Cool SP: 80°F
Cool SP range: 70-76°F
Cool Setback SP: 80°F
Cool SP range: 70-76°F
PV: 85°F, previous PV: 76°F
Start 10-min timer
Sends 85°F to Management Point
Cool SP max 85°F is rounded to 78°F
due to Cool Setback SP 80°F.
Cool SP range: 70-78°F (Changed)
PV 78°F
Reset 10-min timer
Updates 78°F to the BACnet® Server
Sets Cool SP max
85°F again
PV: 85°F, previous PV: 78°F
Start 10-min timer
Sends 85°F to Management Point
Cool SP max 85°F is rounded to 78°F
due to Cool Setback SP 80°F
Cool SP range: 70-78°F (No change)
When 10-min timer expires, PV
back to 78°F
EXAMPLE 2 – Cool SP
Cool SP range: 70-78°F
Cool SP: 72°F
Cool SP range: 70-78°F
Cool SP: 72°F
PV: 68°F, previous PV: 72°F
Start 10-min timer
Sends 68°F to Management Point
Cool SP 68°F is rounded to 70°F due to
Cool SP range 70-78°F
Cool SP: 70°F (Changed)
PV 70°F
Reset 10-min timer
Sends 70°F to BACnet® Server
Sets Cool SP 68°F
again
PV: 68°F, previous PV: 70°F
Start 10-min timer
Sends 68°F to Management Point
Cool SP 68°F is rounded to 70°F due to
the Cool SP range 70-78°F
Cool SP: 70°F (No change)
When 10-min timer expires, PV
back to 70°F
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