{
 "manufacturer": "Siemens",
 "manufacturer_slug": "siemens",
 "model": "BACnet ATEC VAV Controller - Applications 6634/6636 (Series or Parallel Fan with Electric Heat)",
 "model_slug": "atec-6634-6636-vav-fan-powered-electric-heat",
 "short_model": "ATEC Fan VAV Electric Heat 6634/6636",
 "aliases": [
  "ATEC 6634",
  "ATEC 6636",
  "Application 6634",
  "Application 6636",
  "App 6634",
  "App 6636",
  "550-430PA",
  "550-431PA"
 ],
 "equipment_type": "Fan-powered VAV terminal unit controller",
 "applies_to": "Series (6634) or parallel (6636) fan-powered VAV boxes with up to three stages of electric heat on the Siemens BACnet ATEC controller (550-430PA / 550-431PA).",
 "summary": "Applications 6634 (series fan) and 6636 (parallel fan) run a fan-powered VAV box with time-modulated electric heat on a Siemens BACnet ATEC controller over BACnet MS/TP. The damper modulates for cooling and up to three heat stages follow the heating loop. The series fan runs all day and at night on heat or supply airflow; the parallel fan runs in heating, set up as a first heat stage or only when supply airflow is too low for the coil.",
 "bacnet_transport": [
  "BACnet MS/TP"
 ],
 "firmware": null,
 "default_device_instance": null,
 "access_inferred": true,
 "notes": [
  "AI and BI objects are read-only. AO and BO objects are BACnet output objects with a priority array; the guide has no access column, so access is inferred from object type. Many AOs are calculated status values, not commands.",
  "Instances shown in braces in the guide may be unbundled at a field panel; that marking is not reproduced here.",
  "Units are given in US units (°F, cfm, ft²); the guide also lists SI factory defaults.",
  "The ATEC is the Siemens VAV controller with the damper actuator built in (550-430PA 44 lb-in or 550-431PA 88 lb-in).",
  "The guide prints separate point tables for 6634 and 6636 with the same objects, names and instances; one list covers both. SERIES ON/OFF apply to 6634, PARALLEL ON/OFF to 6636.",
  "The fan is on DO 6 (BO 46); heat stages are on DO 3-DO 5 (BO 43-45).",
  "The guide's text describes an EHEAT FLOW airflow interlock, but its 6634/6636 point tables have no EHEAT FLOW object."
 ],
 "source": {
  "title": "BACnet ATEC Controller VAV - with Series Fan or Parallel Fan and Electric Heat, Application 6634/6636, Application Note",
  "doc_number": "140-1214",
  "revision_date": "2017-12-12",
  "url": "https://sid.siemens.com/api/khub/documents/967lbuCz~bN4Q2oEmKPGgw/content"
 },
 "integration": {
  "summary": "Give the controller its MS/TP address (CTLR ADDRESS, or Auto Addressing). The BMS commands occupancy with DAY.NGT (BO 29) and the day setpoints, and reads room temperature, airflow, damper position, fan and heat stage status and the error status.",
  "minimum_points": [
   {
    "ref": "BO 29",
    "name": "DAY.NGT",
    "why": "DAY = occupied, NIGHT = unoccupied"
   },
   {
    "ref": "AO 6",
    "name": "DAY CLG STPT",
    "why": "Occupied cooling setpoint, °F"
   },
   {
    "ref": "AO 7",
    "name": "DAY HTG STPT",
    "why": "Occupied heating setpoint, °F"
   },
   {
    "ref": "BO 5",
    "name": "HEAT.COOL",
    "why": "Current mode: HEAT or COOL"
   },
   {
    "ref": "BO 46",
    "name": "FAN",
    "why": "Series or parallel fan on/off"
   },
   {
    "ref": "AI 4",
    "name": "ROOM TEMP",
    "why": "Space temperature"
   },
   {
    "ref": "AI 35",
    "name": "AIR VOLUME",
    "why": "Measured primary airflow, cfm"
   },
   {
    "ref": "AO 49",
    "name": "DMPR POS",
    "why": "Primary air damper position, %"
   },
   {
    "ref": "BO 43",
    "name": "HEAT STAGE 1",
    "why": "Electric heat stage 1 on/off"
   },
   {
    "ref": "AO 99",
    "name": "ERROR STATUS",
    "why": "Controller error code"
   }
  ],
  "enable": "Occupancy is DAY.NGT (BO 29). With a wall switch on AI/DI 4 and WALL SWITCH (BO 18) = YES, the switch sets it; with WALL SWITCH = NO a standalone controller stays in day mode, and on a network the field panel can command DAY.NGT. NGT OVRD (BO 21) shows a temporary day override from the room unit button.",
  "heartbeat": null,
  "remote_sensors": "VENT DMD MIN (AO 47) can be reset by the field panel or PPCL (for example from CO2) to set the occupied ventilation minimum airflow; the larger of it and the cooling or heating minimum is used.",
  "setup": [
   "BACnet MS/TP only. CTLR ADDRESS (AO 1) holds the MS/TP address; the factory value is 255.",
   "APPLICATION (AO 2) shows the application number in the controller; the point table lists a factory value of 6684.",
   "Auto Discovery finds controllers on the MS/TP trunk by serial number; an unaddressed controller can be auto-addressed and detects the baud rate itself.",
   "If PPCL is loaded in the controller (PPCL STATE = LOADED), a new application number from 12000 to 12999 must be assigned."
  ],
  "gotchas": [
   "The guide states the controller, as shipped from the factory, keeps all connected equipment OFF.",
   "With a digital room unit (revision 26 and later), a command sent through the room unit puts the matching BACnet input Out Of Service.",
   "Loop gains, motor timing, rotation angles and setup codes are commissioning values; avoid writing them from the BMS routinely.",
   "If the air velocity sensor fails the box falls back to pressure-dependent damper control; if the room sensor fails it uses the last good value.",
   "Series fan boxes: the box fan must be interlocked to start before or with the central air handler, or it can spin backwards and be damaged.",
   "Parallel fan: the setup that runs the fan only for low supply airflow is meant for coils in the discharge air; with coils in the return/plenum path it can damage them."
  ]
 },
 "points": [
  {
   "type": "AO",
   "instance": 1,
   "name": "CTLR ADDRESS",
   "description": "Controller MS/TP address",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 2,
   "name": "APPLICATION",
   "description": "Application number running in the controller",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 3,
   "name": "RMTMP OFFSET",
   "description": "Room temperature calibration offset",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AI",
   "instance": 4,
   "name": "ROOM TEMP",
   "description": "Room temperature from the room unit",
   "units": "°F",
   "access": "R",
   "states": ""
  },
  {
   "type": "BO",
   "instance": 5,
   "name": "HEAT.COOL",
   "description": "Current heating/cooling mode",
   "units": "",
   "access": "C",
   "states": "0=COOL, 1=HEAT"
  },
  {
   "type": "AO",
   "instance": 6,
   "name": "DAY CLG STPT",
   "description": "Day (occupied) cooling setpoint",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 7,
   "name": "DAY HTG STPT",
   "description": "Day (occupied) heating setpoint",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 8,
   "name": "NGT CLG STPT",
   "description": "Night (unoccupied) cooling setpoint",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 9,
   "name": "NGT HTG STPT",
   "description": "Night (unoccupied) heating setpoint",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 10,
   "name": "DEW POINT",
   "description": "Room dew point",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 11,
   "name": "RM STPT MIN",
   "description": "Lowest setpoint allowed from the room unit",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 12,
   "name": "RM STPT MAX",
   "description": "Highest setpoint allowed from the room unit",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AI",
   "instance": 13,
   "name": "RM STPT DIAL",
   "description": "Setpoint from the room unit dial or keypad",
   "units": "°F",
   "access": "R",
   "states": ""
  },
  {
   "type": "BO",
   "instance": 14,
   "name": "STPT DIAL",
   "description": "Use the room unit setpoint dial",
   "units": "",
   "access": "C",
   "states": "0=NO, 1=YES"
  },
  {
   "type": "AI",
   "instance": 15,
   "name": "AUX TEMP AI3",
   "description": "Spare temperature input on AI 3",
   "units": "°F",
   "access": "R",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 16,
   "name": "FLOW START",
   "description": "Heating loop % where airflow starts to rise",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 17,
   "name": "FLOW END",
   "description": "Heating loop % where airflow reaches maximum",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "BO",
   "instance": 18,
   "name": "WALL SWITCH",
   "description": "Use a wall switch on AI/DI 4 for day/night",
   "units": "",
   "access": "C",
   "states": "0=NO, 1=YES"
  },
  {
   "type": "BI",
   "instance": 19,
   "name": "DI OVRD SW",
   "description": "Room unit night override button",
   "units": "",
   "access": "R",
   "states": "0=OFF, 1=ON"
  },
  {
   "type": "AO",
   "instance": 20,
   "name": "OVRD TIME",
   "description": "Night override duration",
   "units": "h",
   "access": "C",
   "states": ""
  },
  {
   "type": "BO",
   "instance": 21,
   "name": "NGT OVRD",
   "description": "Night override status",
   "units": "",
   "access": "C",
   "states": "0=DAY, 1=NIGHT"
  },
  {
   "type": "AO",
   "instance": 22,
   "name": "REHEAT START",
   "description": "Heating loop % where reheat starts",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 23,
   "name": "REHEAT END",
   "description": "Heating loop % where reheat is at full output",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "BI",
   "instance": 24,
   "name": "DI 4",
   "description": "Digital input 4",
   "units": "",
   "access": "R",
   "states": "0=OFF, 1=ON"
  },
  {
   "type": "BI",
   "instance": 25,
   "name": "DI 3",
   "description": "Digital input 3",
   "units": "",
   "access": "R",
   "states": "0=OFF, 1=ON"
  },
  {
   "type": "AO",
   "instance": 26,
   "name": "SERIES ON",
   "description": "Night: FLOW % above which the series fan starts",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 27,
   "name": "SERIES OFF",
   "description": "Night: FLOW % below which the series fan may stop",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 28,
   "name": "PARALLEL ON",
   "description": "Heating: FLOW % below which the parallel fan may start",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "BO",
   "instance": 29,
   "name": "DAY.NGT",
   "description": "Day/night (occupancy) mode",
   "units": "",
   "access": "C",
   "states": "0=DAY, 1=NIGHT"
  },
  {
   "type": "AO",
   "instance": 30,
   "name": "PARALLEL OFF",
   "description": "Heating: FLOW % above which the parallel fan stops",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 31,
   "name": "CLG FLOW MIN",
   "description": "Minimum airflow in cooling",
   "units": "cfm",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 32,
   "name": "CLG FLOW MAX",
   "description": "Maximum airflow in cooling",
   "units": "cfm",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 33,
   "name": "HTG FLOW MIN",
   "description": "Minimum airflow in heating",
   "units": "cfm",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 34,
   "name": "HTG FLOW MAX",
   "description": "Maximum airflow in heating",
   "units": "cfm",
   "access": "C",
   "states": ""
  },
  {
   "type": "AI",
   "instance": 35,
   "name": "AIR VOLUME",
   "description": "Measured airflow",
   "units": "cfm",
   "access": "R",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 36,
   "name": "FLOW COEFF",
   "description": "Flow coefficient (box sizing value)",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 40,
   "name": "NGT FLOW MIN",
   "description": "Minimum airflow at night",
   "units": "cfm",
   "access": "C",
   "states": ""
  },
  {
   "type": "BO",
   "instance": 41,
   "name": "DO 1",
   "description": "Digital output 1",
   "units": "",
   "access": "C",
   "states": "0=OFF, 1=ON"
  },
  {
   "type": "BO",
   "instance": 42,
   "name": "DO 2",
   "description": "Digital output 2",
   "units": "",
   "access": "C",
   "states": "0=OFF, 1=ON"
  },
  {
   "type": "BO",
   "instance": 43,
   "name": "HEAT STAGE 1",
   "description": "Electric heat stage 1 output",
   "units": "",
   "access": "C",
   "states": "0=OFF, 1=ON"
  },
  {
   "type": "BO",
   "instance": 44,
   "name": "HEAT STAGE 2",
   "description": "Electric heat stage 2 output",
   "units": "",
   "access": "C",
   "states": "0=OFF, 1=ON"
  },
  {
   "type": "BO",
   "instance": 45,
   "name": "HEAT STAGE 3",
   "description": "Electric heat stage 3 output",
   "units": "",
   "access": "C",
   "states": "0=OFF, 1=ON"
  },
  {
   "type": "BO",
   "instance": 46,
   "name": "FAN",
   "description": "Fan command",
   "units": "",
   "access": "C",
   "states": "0=OFF, 1=ON"
  },
  {
   "type": "AO",
   "instance": 47,
   "name": "VENT DMD MIN",
   "description": "Ventilation demand minimum airflow",
   "units": "cfm",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 48,
   "name": "DMPR COMD",
   "description": "Damper position command",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 49,
   "name": "DMPR POS",
   "description": "Damper position",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AI",
   "instance": 50,
   "name": "AI 4",
   "description": "Spare temperature input on AI 4",
   "units": "°F",
   "access": "R",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 51,
   "name": "MTR1 TIMING",
   "description": "Motor 1 full-stroke time",
   "units": "s",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 54,
   "name": "STPT SPAN",
   "description": "Room unit setpoint adjustment span",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 56,
   "name": "DMPR ROT ANG",
   "description": "Damper rotation angle",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 58,
   "name": "MTR SETUP",
   "description": "Motor setup code",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 59,
   "name": "DO DIR. REV",
   "description": "Digital output direction reverse setting",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 63,
   "name": "CLG P GAIN",
   "description": "Cooling loop proportional gain",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 64,
   "name": "CLG I GAIN",
   "description": "Cooling loop integral gain",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 65,
   "name": "CLG D GAIN",
   "description": "Cooling loop derivative gain",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "BO",
   "instance": 66,
   "name": "CHK OUT",
   "description": "Start the built-in checkout (fault detection) routine",
   "units": "",
   "access": "C",
   "states": "0=NO, 1=YES"
  },
  {
   "type": "AO",
   "instance": 67,
   "name": "HTG P GAIN",
   "description": "Heating loop proportional gain",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 68,
   "name": "HTG I GAIN",
   "description": "Heating loop integral gain",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 69,
   "name": "HTG D GAIN",
   "description": "Heating loop derivative gain",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 70,
   "name": "CHK STATUS",
   "description": "Checkout result code (additive; -1 = not run)",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 71,
   "name": "FLOW P GAIN",
   "description": "Flow loop proportional gain",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 72,
   "name": "FLOW I GAIN",
   "description": "Flow loop integral gain",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 73,
   "name": "FLOW D GAIN",
   "description": "Flow loop derivative gain",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 74,
   "name": "FLOW BIAS",
   "description": "Flow loop bias",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 75,
   "name": "FLOW",
   "description": "Airflow as percent of maximum",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 76,
   "name": "CTL FLOW MIN",
   "description": "Active minimum airflow",
   "units": "cfm",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 77,
   "name": "CTL FLOW MAX",
   "description": "Active maximum airflow",
   "units": "cfm",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 78,
   "name": "CTL TEMP",
   "description": "Temperature the controller is controlling to",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 79,
   "name": "CLG LOOPOUT",
   "description": "Cooling loop output",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 80,
   "name": "HTG LOOPOUT",
   "description": "Heating loop output",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 81,
   "name": "AVG HEAT OUT",
   "description": "Average auxiliary heat output",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 82,
   "name": "STAGE MAX",
   "description": "Heat stage maximum, % (not described in the guide)",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 83,
   "name": "STAGE MIN",
   "description": "Heat stage minimum, % (not described in the guide)",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 84,
   "name": "AOV 1",
   "description": "Analog output 1 (0-10 V)",
   "units": "V",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 85,
   "name": "SWITCH LIMIT",
   "description": "Loop output below which mode may switch",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 86,
   "name": "SWITCH TIME",
   "description": "Minimum time before heat/cool switchover",
   "units": "min",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 88,
   "name": "STAGE COUNT",
   "description": "Number of electric heat stages",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 89,
   "name": "STAGE TIME",
   "description": "Electric heat cycle time",
   "units": "min",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 90,
   "name": "SWITCH DBAND",
   "description": "Temperature deadband for heat/cool switchover",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 92,
   "name": "CTL STPT",
   "description": "Active control setpoint",
   "units": "°F",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 93,
   "name": "FLOW STPT",
   "description": "Airflow setpoint, percent",
   "units": "%",
   "access": "C",
   "states": ""
  },
  {
   "type": "BO",
   "instance": 94,
   "name": "CAL AIR",
   "description": "Start air velocity sensor calibration",
   "units": "",
   "access": "C",
   "states": "0=NO, 1=YES"
  },
  {
   "type": "AO",
   "instance": 95,
   "name": "CAL SETUP",
   "description": "Calibration setup code",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 96,
   "name": "CAL TIMER",
   "description": "Calibration timer",
   "units": "h",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 97,
   "name": "DUCT AREA",
   "description": "Inlet duct area for airflow calculation",
   "units": "ft²",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 98,
   "name": "LOOP TIME",
   "description": "Control loop interval",
   "units": "s",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 99,
   "name": "ERROR STATUS",
   "description": "Controller error status code",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AO",
   "instance": 124,
   "name": "SENSOR SEL",
   "description": "Room unit / sensor select code (additive)",
   "units": "",
   "access": "C",
   "states": ""
  },
  {
   "type": "AI",
   "instance": 125,
   "name": "RM CO2",
   "description": "Room CO2",
   "units": "ppm",
   "access": "R",
   "states": ""
  },
  {
   "type": "AI",
   "instance": 126,
   "name": "RM RH",
   "description": "Room relative humidity",
   "units": "%",
   "access": "R",
   "states": ""
  },
  {
   "type": "BO",
   "instance": 127,
   "name": "PPCL STATE",
   "description": "PPCL program loaded or empty",
   "units": "",
   "access": "C",
   "states": "0=EMPTY, 1=LOADED"
  }
 ],
 "page": "https://easybacnet.com/bacnet-points-lists/siemens/atec-6634-6636-vav-fan-powered-electric-heat",
 "note": "Re-typed from the manufacturer's public documentation (see source). Point availability varies by firmware and options; verify against the live device."
}