{
 "manufacturer": "Dwyer",
 "manufacturer_slug": "dwyer",
 "model": "Series GSTC carbon monoxide / nitrogen dioxide gas transmitter, BACnet MS/TP",
 "model_slug": "gstc-co-no2-gas-transmitter",
 "aliases": [
  "GSTC",
  "GSTC-C",
  "GSTC-N",
  "Series GSTC",
  "DwyerOmega GSTC",
  "CO Detector",
  "NO2 Detector"
 ],
 "equipment_type": "CO / NO2 gas sensor",
 "applies_to": "Dwyer Series GSTC carbon monoxide (GSTC-C) and nitrogen dioxide (GSTC-N) gas transmitters with switch-selectable BACnet MS/TP or Modbus RTU.",
 "summary": "The GSTC is an electrochemical CO or NO2 transmitter for parking garages and similar spaces. A DIP switch picks BACnet MS/TP or Modbus RTU. Over BACnet it has one Analog Input for the gas level in ppm, a Binary Value to zero the sensor and two Date Values the user fills in for the calibration and sensor replacement dates.",
 "bacnet_transport": [
  "BACnet MS/TP"
 ],
 "firmware": null,
 "default_device_instance": "607000 + DIP switch address (607xxx)",
 "access_inferred": false,
 "notes": [
  "AI 1 is named \"CO Concentration\" on CO models and \"NO2 Concentration\" on NO2 models.",
  "Calibration Date and Replace Sensor Date are BACnet Date Value objects (DV 1, DV 2), listed here as Other.",
  "The Date Values are not tracked by the transmitter; someone has to write them after field calibration or sensor replacement.",
  "The BV 1 property table shows Present_Value as Read, but the text says writing it active zeroes the sensor; marked writable here."
 ],
 "source": {
  "title": "Series GSTC Carbon Monoxide / Nitrogen Dioxide Gas Transmitter - Specifications, Installation and Operating Instructions",
  "doc_number": "Bulletin AQ-GSTC (FR# 443872-00 Rev. 6)",
  "revision_date": "2/19",
  "url": "https://core.instrumart.com/assets/Dwyer-GSTC-Manual.pdf",
  "unofficial": true,
  "host": "Instrumart"
 },
 "integration": {
  "summary": "Set the address and BACnet protocol on the DIP switches and read AI 1 for the gas level in ppm. Alarm and fan logic live in the BMS.",
  "minimum_points": [
   {
    "ref": "AI 1",
    "name": "CO Concentration",
    "why": "Gas level, ppm (CO or NO2 by model)"
   }
  ],
  "enable": null,
  "heartbeat": null,
  "remote_sensors": null,
  "setup": [
   "Address and protocol (BACnet or Modbus) are set on the DIP switches; valid BACnet addresses are 1-127.",
   "Device instance defaults to 607xxx, where xxx is the DIP switch address.",
   "Auto-baud detects the bus speed after power-up.",
   "DeviceCommunicationControl and ReinitializeDevice need the password \"Dwyer\"."
  ],
  "gotchas": [
   "Electrochemical sensors drift; Dwyer recommends recalibration every 6 months (5% accuracy holds at 12-month intervals)."
  ]
 },
 "points": [
  {
   "type": "AI",
   "instance": 1,
   "name": "CO Concentration",
   "description": "CO (GSTC-C) or NO2 (GSTC-N) gas level",
   "units": "ppm",
   "access": "R",
   "states": ""
  },
  {
   "type": "BV",
   "instance": 1,
   "name": "Zero Sensor",
   "description": "Write active to re-zero the sensor",
   "units": "",
   "access": "W",
   "states": "0=Inactive, 1=Active"
  },
  {
   "type": "Other",
   "instance": 1,
   "name": "Calibration Date",
   "description": "Date Value: last calibration date, entered manually",
   "units": "",
   "access": "W",
   "states": ""
  },
  {
   "type": "Other",
   "instance": 2,
   "name": "Replace Sensor Date",
   "description": "Date Value: suggested sensor replacement date, entered manually",
   "units": "",
   "access": "W",
   "states": ""
  }
 ],
 "page": "https://easybacnet.com/bacnet-points-lists/dwyer/gstc-co-no2-gas-transmitter",
 "note": "Provided as-is. Point availability varies by firmware and options; verify against the live device.",
 "disclaimer": "DISCLAIMER: reference only, provided AS IS with no warranty. May contain errors or be out of date. You must verify every point against the manufacturer's current documentation and the live device before use. easybacnet.com accepts no liability for its use and is not affiliated with the manufacturer. Terms: https://easybacnet.com/terms#content"
}