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Dual duct VAV terminal unit controller · BACnet points list

Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover) BACnet points list

Updated 28 October 2026

Short answer

Application 6669 controls a dual duct VAV box on a Siemens BACnet PTEC controller over BACnet MS/TP, with a separate airflow loop and damper for the cold and hot duct. In cooling the cold duct damper holds room temperature while the hot duct keeps the minimum flow; in heating the roles swap. The hot duct can act as a second cold duct (HOT.COLD), and optional auxiliary heat can be a hot water valve or up to three electric stages.

This page lists 110 BACnet objects for the Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover) — 95 of them writable — with each object’s type, instance number, name, engineering units and access. It is re-typed from Siemens’s own free documentation, linked below.

Manufacturer
Siemens
Model
BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover)
Equipment
Dual duct VAV terminal unit controller
Equipment type
VAV boxes & fan coils
BACnet objects
110 (95 writable)
Transport
BACnet MS/TP
Firmware
Newer than revision Bx40
Also known as
PTEC 6669, Application 6669, App 6669, 550-497PA, Siemens dual duct VAV
Source document
BACnet PTEC Controller Dual Duct 2 Air Velocity Sensor - VAV Changeover, Application 6669, Application Note · 140-1117 · rev. 2017-06-23
Download CSV 110 rows Download EDE B.I.G.-EU JSON Manufacturer PDF ↗ Download Easy BACnet Mobile App Google Play

BMS integration notes: Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover)

Integration in brief

Address the controller on the BACnet MS/TP trunk (manually or with auto addressing), then release the box to application control. The BMS commands occupancy with DAY.NGT (BO 29) and the day setpoints, and reads room temperature, the two duct airflows and the error status.

Minimum points to map

The short list most integrators start with — enough to run the unit from a BMS. Map more as the job needs.

ObjectNameWhyAccess
BO 29DAY.NGTDAY = occupied, NIGHT = unoccupiedCommand
AO 6DAY CLG STPTOccupied cooling setpoint, °FCommand
AO 7DAY HTG STPTOccupied heating setpoint, °FCommand
BO 5HEAT.COOLCurrent mode: HEAT or COOLCommand
AI 4ROOM TEMPSpace temperatureRead
AI 35CLG VOLUMECold duct airflow, cfmRead
AI 30HTG VOLUMEHot duct airflow, cfmRead
AO 99ERROR STATUSController error codeCommand

Enable & remote start

Occupancy is DAY.NGT (BO 29). With a wall switch on DI 2 and WALL SWITCH (BO 18) = YES, the switch sets it; standalone with no switch the controller stays in day mode; on a network the field panel or BMS commands DAY.NGT. NGT OVRD (BO 21) shows a temporary night override from the room unit button.

Sensors & values from the BMS

If the hot duct thermistor is not used, HTG DUCTTEMP (AI 15) can be commanded to a value, or HEAT.COOL (BO 5) commanded from the field panel or PPCL, to set the changeover. VENT DMD MIN (AO 77) can be reset by the field panel.

Network setup

Watch out for

Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover) BACnet objects

Type: AI, AO, AV, BI, BO, BV, MI/MO/MV (multi-state) · Access: Read read-only, Write writable, Command writable with a priority array.

Note: the source document has no read/write column, so access here is inferred from the object type (inputs read-only, values writable). Confirm on the live controller before writing.

110 of 110 shown
Type
Access
Show
Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover) BACnet Points List
DescriptionStates
AO1CTLR ADDRESSController MS/TP addressCommand
AO2APPLICATIONApplication number running in the controllerCommand
BO3HOT.COLDHot duct status: hot or cold supply airCommand0=COLD, 1=HOT
AImin4ROOM TEMPRoom temperature from the room unit°FRead
BOmin5HEAT.COOLCurrent heating/cooling modeCommand0=COOL, 1=HEAT
AOmin6DAY CLG STPTDay (occupied) cooling setpoint°FCommand
AOmin7DAY HTG STPTDay (occupied) heating setpoint°FCommand
AO8NGT CLG STPTNight (unoccupied) cooling setpoint°FCommand
AO9NGT HTG STPTNight (unoccupied) heating setpoint°FCommand
BO10SER.PARHot duct sequencing: series or parallelCommand0=PAR, 1=SERIES
AO11RM STPT MINLowest setpoint allowed from the room unit°FCommand
AO12RM STPT MAXHighest setpoint allowed from the room unit°FCommand
AI13RM STPT DIALSetpoint from the room unit dial or keypad°FRead
BO14STPT DIALUse the room unit setpoint dialCommand0=NO, 1=YES
AI15HTG DUCTTEMPHot duct air temperature°FRead
AO16FLOW STARTHeating loop % where airflow starts to rise%Command
AO17FLOW ENDHeating loop % where airflow reaches maximum%Command
BO18WALL SWITCHWall switch connected to DI 2Command0=NO, 1=YES
BI19DI OVRD SWRoom unit night override buttonRead0=OFF, 1=ON
AO20OVRD TIMENight override durationhCommand
BO21NGT OVRDNight override statusCommand0=DAY, 1=NIGHT
AO22REHEAT STARTHeating loop % where reheat starts%Command
AO23REHEAT ENDHeating loop % where reheat is at full output%Command
BI24DI 2Digital input 2Read0=OFF, 1=ON
BI25DI 3Digital input 3Read0=OFF, 1=ON
AO26HTGFLO PGAINHot duct flow loop proportional gainCommand
AO27HTGFLO IGAINHot duct flow loop integral gainCommand
AO28HTGFLO DGAINHot duct flow loop derivative gainCommand
BOmin29DAY.NGTDay/night (occupancy) modeCommand0=DAY, 1=NIGHT
AImin30HTG VOLUMEMeasured hot duct airflowcfmRead
AO32CLG FLOW MAXMaximum airflow in coolingcfmCommand
AO33TOT FLOW MINMinimum total airflow (both ducts)cfmCommand
AO34HTG FLOW MAXMaximum airflow in heatingcfmCommand
AImin35CLG VOLUMEMeasured cold duct airflowcfmRead
AO36CLG FLO COEFCold duct airflow correction coefficientCommand
AO37VALVE COMDReheat valve command%Command
AO38VALVE POSReheat valve position (calculated)%Command
AO39MTR3 TIMINGMotor 3 full-stroke timesCommand
BO41DO 1Digital output 1Command0=OFF, 1=ON
BO42DO 2Digital output 2Command0=OFF, 1=ON
BO43DO 3Digital output 3Command0=OFF, 1=ON
BO44DO 4Digital output 4Command0=OFF, 1=ON
BO45DO 5Digital output 5Command0=OFF, 1=ON
BO46DO 6Digital output 6Command0=OFF, 1=ON
BO47DO 7Digital output 7Command0=OFF, 1=ON
AO48CLG DMP CMDCold duct damper command%Command
AO49CLG DMP POSCold duct damper position%Command
BO50DO 8Digital output 8Command0=OFF, 1=ON
AO51MTR1 TIMINGMotor 1 full-stroke timesCommand
AO52HTG DMP CMDHot duct damper command%Command
AO53HTG DMP POSHot duct damper position%Command
AO54HTG FLO COEFHot duct airflow correction coefficientCommand
AO55MTR2 TIMINGMotor 2 full-stroke timesCommand
AO56DPR1 ROT ANGDamper 1 rotation angleCommand
AO57DPR2 ROT ANGDamper 2 rotation angleCommand
AO58MTR SETUPMotor enable/reverse setup (additive code)Command
AO59DO DIR. REVDigital output direction reverse (additive code)Command
AO60HTGDUCT AREAHot duct inlet areaft²Command
AO61CLG TEMPDuct temp below which air counts as cold°FCommand
AO62HTG TEMPDuct temp above which air counts as hot°FCommand
AO63CLG P GAINCooling loop proportional gainCommand
AO64CLG I GAINCooling loop integral gainCommand
AO65CLG D GAINCooling loop derivative gainCommand
AO66CLG BIASCooling loop bias%Command
AO67HTG P GAINHeating loop proportional gainCommand
AO68HTG I GAINHeating loop integral gainCommand
AO69HTG D GAINHeating loop derivative gainCommand
AO70HTG BIASHeating loop bias%Command
AO71CLGFLO PGAINCold duct flow loop proportional gainCommand
AO72CLGFLO IGAINCold duct flow loop integral gainCommand
AO73CLGFLO DGAINCold duct flow loop derivative gainCommand
AO74HTG FLOWHot duct airflow, percent%Command
AO75CLG FLOWCold duct airflow, percent%Command
AO76NGT FLOW MINMinimum airflow at nightcfmCommand
AO77VENT DMD MINVentilation demand minimum airflowcfmCommand
AO78CTL TEMPTemperature the controller is controlling to°FCommand
AO79CLG LOOPOUTCooling loop output%Command
AO80HTG LOOPOUTHeating loop output%Command
AO81AVG HEAT OUTAverage auxiliary heat output%Command
BO82AUX HTG USEDAuxiliary heat installedCommand0=NO, 1=YES
BO83AUX HTG TYPEAuxiliary heat type: electric or hot waterCommand0=HW, 1=ELEC
AO85HTG FLO STPTHot duct airflow setpoint, percent%Command
AO86SWITCH TIMEMinimum time before heat/cool switchoverminCommand
BO87CAL MODULECalibration module installedCommand0=NO, 1=YES
AO88STAGE COUNTNumber of electric heat stagesCommand
AO89STAGE TIMEElectric heat cycle timeminCommand
AO90SWITCH DBANDTemperature deadband for heat/cool switchover°FCommand
AO91CLG FLOW MINMinimum airflow in coolingcfmCommand
AO92CTL STPTActive control setpoint°FCommand
AO93CLG FLO STPTCold duct airflow setpoint, percent%Command
BO94CAL AIRStart air velocity sensor calibrationCommand0=NO, 1=YES
AO95CAL SETUPCalibration setup codeCommand
AO96CAL TIMERHours between automatic calibrationshCommand
AO97CLGDUCT AREACold duct inlet areaft²Command
AO98LOOP TIMEControl loop intervalsCommand
AOmin99ERROR STATUSController error status codeCommand
AO102AOV 1Analog output 1 (0-10 V)VCommand
AO103AOV 2Analog output 2 (0-10 V)VCommand
AO104AOV 3Analog output 3 (0-10 V)VCommand
AI105AI 3Spare analog input 3%Read
AI106AI 4Spare analog input 4%Read
AO107RMTMP OFFSETRoom temperature calibration offset°FCommand
BI108DI 4Digital input 4Read0=OFF, 1=ON
BI109DI 5Digital input 5Read0=OFF, 1=ON
BI110DI 6Digital input 6Read0=OFF, 1=ON
AO111STPT SPANRoom unit setpoint adjustment span°FCommand
AO124SENSOR SELRoom unit / sensor select code (additive)Command
AI125RM CO2Room CO2ppmRead
AI126RM RHRoom relative humidity%Read
BO127PPCL STATEPPCL program loaded or emptyCommand0=EMPTY, 1=LOADED

Integration notes

Check it against the live device. A points list tells you what the controller can expose; the unit in front of you may differ by firmware or installed options. Easy BACnet scans a network for BACnet IP devices from an Android phone, reads every object on the BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover) and exports what it actually has to Excel — free. New to BACnet? Start with what a BACnet points list is and what the object types mean.

Questions about the Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover)

How many BACnet points does the Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover) have?

This list has 110 BACnet objects: 9 analog inputs, 75 analog outputs, 6 binary inputs, 20 binary outputs. The exact set on a given unit depends on its firmware, installed options and configuration.

Which Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover) BACnet points are writable?

95 of the 110 objects accept a write. Points marked Command have a priority array: a write holds until it is released, so release it back to automatic when you are done. The source has no read/write column, so this is inferred from object type.

Where is the official Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover) BACnet documentation?

The source is BACnet PTEC Controller Dual Duct 2 Air Velocity Sensor - VAV Changeover, Application 6669, Application Note (140-1117), revision 2017-06-23, published free by Siemens at https://sid.siemens.com/api/khub/documents/LpGnvh2K_A2479_up7VqUg/content.

What are the minimum BACnet points to integrate the Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover)?

Start with BO 29 DAY.NGT (DAY = occupied, NIGHT = unoccupied); AO 6 DAY CLG STPT (Occupied cooling setpoint, °F); AO 7 DAY HTG STPT (Occupied heating setpoint, °F); BO 5 HEAT.COOL (Current mode: HEAT or COOL); AI 4 ROOM TEMP (Space temperature); AI 35 CLG VOLUME (Cold duct airflow, cfm); AI 30 HTG VOLUME (Hot duct airflow, cfm); AO 99 ERROR STATUS (Controller error code).

How do I enable BMS control of the Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover)?

Occupancy is DAY.NGT (BO 29). With a wall switch on DI 2 and WALL SWITCH (BO 18) = YES, the switch sets it; standalone with no switch the controller stays in day mode; on a network the field panel or BMS commands DAY.NGT. NGT OVRD (BO 21) shows a temporary night override from the room unit button.

Can the BMS supply sensor values to the Siemens BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover)?

If the hot duct thermistor is not used, HTG DUCTTEMP (AI 15) can be commanded to a value, or HEAT.COOL (BO 5) commanded from the field panel or PPCL, to set the changeover. VENT DMD MIN (AO 77) can be reset by the field panel.

How do I check these points on the real BACnet PTEC Dual Duct Controller - Application 6669 (2 Air Velocity Sensors, VAV Changeover)?

Scan the network with a BACnet IP browser such as Easy BACnet, open the device and compare its object list with this table. Anything missing is usually an option that isn't installed or a point that is disabled in the controller's configuration.

More Siemens BACnet points lists

Source: BACnet PTEC Controller Dual Duct 2 Air Velocity Sensor - VAV Changeover, Application 6669, Application Note · 140-1117 · rev. 2017-06-23. Object names, instances and units are reproduced as published; descriptions are our own.