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Indoor air quality multi-sensor (CO2 / PM / VOC / formaldehyde) · BACnet points list
Greystone Energy Systems IAQRM Series multi-sensor (BACnet MS/TP) BACnet points list
Updated 6 November 2026
The IAQRM is a Greystone room air-quality multi-sensor with native BACnet MS/TP. Fourteen Analog Inputs report VOC, RH, temperature, PM1.0-PM10 mass and particle counts, CO2 and formaldehyde; Analog Values hold offsets, CO2 altitude and the relay settings, Binary Values select units and switch individual sensors and display features, and Multi-State Values assign the relay and VOC units.
This page lists 36 BACnet objects for the Greystone Energy Systems IAQRM Series multi-sensor (BACnet MS/TP) — 21 of them writable — with each object’s type, instance number, name, engineering units and access. It is re-typed from Greystone Energy Systems’s own free documentation, linked below.
- Manufacturer
- Greystone Energy Systems
- Model
- IAQRM Series multi-sensor (BACnet MS/TP)
- Equipment
- Indoor air quality multi-sensor (CO2 / PM / VOC / formaldehyde)
- Equipment type
- Thermostats, sensors & meters
- BACnet objects
- 36 (21 writable)
- Transport
- BACnet MS/TP
- Firmware
- 1.0 (PICS, March 15, 2023)
- Default device instance
- 381003
- Also known as
- IAQRM, MSN, IAQRMXXXBAC, Greystone indoor air quality multi sensor
Reference only, provided as-is: verify against Greystone Energy Systems’s current documentation and the live device before use. Not official Greystone Energy Systems information. Terms of use.
BMS integration notes: Greystone Energy Systems IAQRM Series multi-sensor (BACnet MS/TP)
Set the MS/TP MAC in the menu, then read the fitted measurements: CO2, PM2.5, VOC, temperature and RH. Treat a value of -1000 as a sensor error.
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.
| Object | Name | Why | Access |
|---|---|---|---|
| AI 13 | CO2 Sensor Value | Room CO2, ppm | Read |
| AI 5 | PM 2.5 Particulate Mass | PM2.5, µg/m3 | Read |
| AI 1 | VOC Sensor Value | VOC level (index, ppb or µg/m3) | Read |
| AI 3 | Temperature Sensor Value | Room temperature | Read |
| AI 2 | RH Sensor Value | Room RH | Read |
| AI 14 | Formaldehyde Sensor Value | Formaldehyde level | Read |
| BI 1 | Relay Status | Relay alarm active | Read |
Network setup
- Device instance defaults to 381003 (381000 + MAC); it stops following the MAC once written over BACnet.
- MS/TP baud rates 9600-115200 are supported.
Watch out for
- A reading of -1000 means a sensor error, not a real value.
- Disabling a sensor with BV 6-9 stops that measurement.
Greystone Energy Systems IAQRM Series multi-sensor (BACnet MS/TP) 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.
| Description | States | |||||
|---|---|---|---|---|---|---|
| AImin | 1 | VOC Sensor Value | VOC: 0-500 index, ppb or µg/m3 per MV 2 | VOC index / ppb / µg/m3 | Read | |
| AImin | 2 | RH Sensor Value | Relative humidity, 0-100 % | %RH | Read | |
| AImin | 3 | Temperature Sensor Value | Temperature, 0-50 °C | °C / °F | Read | |
| AI | 4 | PM 1.0 Particulate Mass | PM1.0 mass, 0-1000 µg/m3 | µg/m3 | Read | |
| AImin | 5 | PM 2.5 Particulate Mass | PM2.5 mass, 0-1000 µg/m3 | µg/m3 | Read | |
| AI | 6 | PM 4.0 Particulate Mass | PM4.0 mass, 0-1000 µg/m3 | µg/m3 | Read | |
| AI | 7 | PM 10 Particulate Mass | PM10 mass, 0-1000 µg/m3 | µg/m3 | Read | |
| AI | 8 | PM 0.5 Number concentration range | PM0.5 particle count, 0-3000 #/cm3 | #/cm3 | Read | |
| AI | 9 | PM 1.0 Number concentration range | PM1.0 particle count, 0-3000 #/cm3 | #/cm3 | Read | |
| AI | 10 | PM 2.5 Number concentration range | PM2.5 particle count, 0-3000 #/cm3 | #/cm3 | Read | |
| AI | 11 | PM 4.0 Number concentration range | PM4.0 particle count, 0-3000 #/cm3 | #/cm3 | Read | |
| AI | 12 | PM10 Number concentration range | PM10 particle count, 0-3000 #/cm3 | #/cm3 | Read | |
| AImin | 13 | CO2 Sensor Value | CO2, 0-10,000 ppm | ppm | Read | |
| AImin | 14 | Formaldehyde Sensor Value | Formaldehyde, 0-1230 µg/m3 or 0-1000 ppb (per BV 2) | µg/m3 / ppb | Read | |
| AV | 1 | Temperature Offset | Temperature offset, ±5 Δ°C or ±10 Δ°F (default 0) | delta °C / °F | Write | |
| AV | 2 | Humidity Offset | RH offset, ±10 %RH (default 0) | %RH | Write | |
| AV | 3 | CO2 Offset | CO2 offset, ±200 ppm (default 0) | ppm | Write | |
| AV | 4 | CO2 Altitude Adjustment | Altitude for CO2 correction, 0-3000 m (default 0) | m | Write | |
| AV | 5 | Relay Setpoint | Relay trip point; range follows MV 1 (default 26 °C) | Write | ||
| AV | 6 | Relay Hysteresis | Relay hysteresis; range follows MV 1 (default 2 °C) | Write | ||
| AV | 7 | Relay On Time | Relay on/off delay, 0-255 s (default 15) | s | Write | |
| BV | 1 | Temperature Units | Temperature unit select | Write | 0=°C, 1=°F | |
| BV | 2 | CH2O Units | Formaldehyde unit select | Write | 0=µg/m3, 1=ppb | |
| BV | 3 | Relay Test | Forces the relay for testing | Write | 0=Inactive, 1=Test | |
| BV | 4 | LCD Backlight | LCD backlight | Write | 0=Enabled, 1=Disabled | |
| BV | 5 | CO2 ASC | CO2 automatic self-calibration | Write | 0=Enabled, 1=Disabled | |
| BV | 6 | CO2 Availability | CO2 sensor in use | Write | 0=Enabled, 1=Disabled | |
| BV | 7 | VOC Availability | VOC sensor in use | Write | 0=Enabled, 1=Disabled | |
| BV | 8 | PM Availability | PM sensor in use | Write | 0=Enabled, 1=Disabled | |
| BV | 9 | CH2O Availability | Formaldehyde sensor in use | Write | 0=Enabled, 1=Disabled | |
| BV | 10 | LED Availability | Status LED | Write | 0=Enabled, 1=Disabled | |
| BV | 11 | Status Bars Availability | Display status bars | Write | 0=Enabled, 1=Disabled | |
| BV | 12 | Touch Screen Availability | Touch screen | Write | 0=Enabled, 1=Disabled | |
| BImin | 1 | Relay Status | Relay alarm state | Read | 0=Normal, 1=Alarm | |
| MV | 1 | Relay Assignment | Reading that drives the relay (default 3) | Write | 0=No Relay, 1=VOC, 2=RH, 3=Temperature, 4=CO2, 5=PM_MASS, 6=PM_NUMBER, 7=CH2O | |
| MV | 2 | Set VOC Units | VOC reporting units (default 1) | Write | 1=VOCI, 2=PPB, 3=ug/m3 |
No points match these filters.
Object ID lookup: Greystone Energy Systems IAQRM Series multi-sensor point IDs by name
AI1VOC Sensor ValueAI2RH Sensor ValueAI3Temperature Sensor ValueAI4PM 1.0 Particulate MassAI5PM 2.5 Particulate MassAI6PM 4.0 Particulate MassAI7PM 10 Particulate MassAI8PM 0.5 Number concentration rangeAI9PM 1.0 Number concentration rangeAI10PM 2.5 Number concentration rangeAI11PM 4.0 Number concentration rangeAI12PM10 Number concentration rangeAI13CO2 Sensor ValueAI14Formaldehyde Sensor ValueAV1Temperature OffsetAV2Humidity OffsetAV3CO2 OffsetAV4CO2 Altitude AdjustmentAV5Relay SetpointAV6Relay HysteresisAV7Relay On TimeBV1Temperature UnitsBV2CH2O UnitsBV3Relay TestBV4LCD BacklightBV5CO2 ASCBV6CO2 AvailabilityBV7VOC AvailabilityBV8PM AvailabilityBV9CH2O AvailabilityBV10LED AvailabilityBV11Status Bars AvailabilityBV12Touch Screen AvailabilityBI1Relay StatusMV1Relay AssignmentMV2Set VOC Units
Integration notes
- Points from the object table in the setup guide (pages 1-5).
- Every AI reads -1000 when its sensor has an error; uninstalled sensors report NO_SENSOR / FAULT.
- The guide lists the BACnet units of the particle-count AIs (AI 8-12) as micrograms-per-cubic-meter, although the values are counts per cm3.
- Relay setpoint and hysteresis ranges depend on MV 1 (e.g. CO2 500-9000 ppm, RH 20-90 %RH).
- Multistate objects are MSV in the guide; listed here as MV. Access from the PICS: AV, BV and MSV Present_Value are writable.
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. This list is provided as-is for reference only and may contain mistakes — confirming it before you write, map or commission anything is up to you (terms). Easy BACnet scans a network for BACnet IP devices from an Android phone, reads every object on the IAQRM Series multi-sensor (BACnet MS/TP) 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 Greystone Energy Systems IAQRM Series multi-sensor (BACnet MS/TP)
How many BACnet points does the Greystone Energy Systems IAQRM Series multi-sensor (BACnet MS/TP) have?
This list has 36 BACnet objects: 14 analog inputs, 7 analog values, 1 binary input, 12 binary values, 2 multi-state values. The exact set on a given unit depends on its firmware, installed options and configuration.
Which Greystone Energy Systems IAQRM Series multi-sensor (BACnet MS/TP) BACnet points are writable?
21 of the 36 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.
Where is the official Greystone Energy Systems IAQRM Series multi-sensor (BACnet MS/TP) BACnet documentation?
The source is IAQRM Series Multi Sensor - Setup Guide BACnet Communication (SG-IAQRMXXXBAC-001), revision 03/23, published free by Greystone Energy Systems at https://downloads.greystoneenergy.com/SG/SG-IAQXXXBAC-001.pdf.
What are the minimum BACnet points to integrate the Greystone Energy Systems IAQRM Series multi-sensor (BACnet MS/TP)?
Start with AI 13 CO2 Sensor Value (Room CO2, ppm); AI 5 PM 2.5 Particulate Mass (PM2.5, µg/m3); AI 1 VOC Sensor Value (VOC level (index, ppb or µg/m3)); AI 3 Temperature Sensor Value (Room temperature); AI 2 RH Sensor Value (Room RH); AI 14 Formaldehyde Sensor Value (Formaldehyde level); BI 1 Relay Status (Relay alarm active).
How do I check these points on the real IAQRM Series multi-sensor (BACnet MS/TP)?
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 Greystone Energy Systems BACnet points lists
- CO2 sensor / transmitter
Greystone Energy Systems CDD3 Series CO2 transmitter (BACnet MS/TP)
Greystone CDD3 series room CO2 transmitters with the BACnet MS/TP output, with optional RH, temperature, relay and setpoint.
Also known as: CDD3, CDD3A1XXXBAC, CDD3 BACnet, Greystone CDD3 CO2 - CO2 / RH / temperature sensor
Greystone Energy Systems CHT Series CO2 / RH / temperature sensor (BACnet MS/TP)
Greystone CHT series combined CO2, humidity and temperature sensors with the BACnet MS/TP output.
Also known as: CHT, CHTDT, CHTXXXBAC, Greystone CHT - Carbon monoxide (CO) gas sensor / transmitter
Greystone Energy Systems CMD Series CO transmitter (BACnet MS/TP)
Greystone CMD series carbon monoxide transmitters (model name CMD5B) with BACnet MS/TP, with optional relays, buzzer and temperature.
Also known as: CMD, CMD5B, CMDXXXBAC, Greystone CMD carbon monoxide - Room temperature / RH / differential pressure monitor
Greystone Energy Systems CR3 Series cleanroom monitor (BACnet MS/TP)
Greystone CR3 series cleanroom and critical-room monitors measuring temperature, humidity and room differential pressure, with BACnet MS/TP.
Also known as: CR3, CR3XXXBAC, CR3C, Greystone CR3 critical room monitor - Room dewpoint / humidity sensor
Greystone Energy Systems DPRC Series room dewpoint transmitter (BACnet MS/TP)
Greystone DPRC series room dewpoint transmitters (PICS model DPRCB) with BACnet MS/TP.
Also known as: DPRC, DPRCB, DPRCXXXBAC, Greystone room dewpoint sensor - Duct / outdoor dewpoint and humidity sensor
Greystone Energy Systems DW Series duct / outside air dewpoint transmitter (BACnet MS/TP)
Greystone DW series duct and outside-air dewpoint transmitters (PICS models DPDDB and DPODB) and HTX2 high-accuracy RH/T transmitters with BACnet MS/TP.
Also known as: DW, DPDDB, DPODB, DWXXXBAC, Greystone duct dewpoint sensor, HTX2, HTX2XXXBAC, Greystone HTX2 high accuracy humidity transmitter - Gas detector / sensor (CO and NO2)
Greystone Energy Systems GDT Series toxic gas detector, CO / NO2 (BACnet MS/TP)
Greystone GDT series toxic gas detectors with CO and/or NO2 sensors, relays, buzzer and strobe, using BACnet MS/TP (typical for parking garages).
Also known as: GDT, GDTXXXBAC, GS, Greystone CO NO2 gas detector, parking garage gas detector - Greenhouse CO2 / RH / temperature sensor
Greystone Energy Systems GH Series horticulture sensor (BACnet MS/TP)
Greystone GH series horticulture (greenhouse / grow room) sensors measuring temperature, humidity and CO2, with BACnet MS/TP.
Also known as: GH, GHXXXBAC, Greystone greenhouse CO2 RH temperature sensor - Greenhouse CO2 sensor
Greystone Energy Systems GO3 Series horticulture CO2 sensor (BACnet MS/TP)
Greystone GO3 series horticulture CO2 sensors (0-20,000 ppm) with optional temperature, RH and relay, using BACnet MS/TP.
Also known as: GO3, GO3 BACnet, Greystone GO3 greenhouse CO2 - Humidity / temperature sensor
Greystone Energy Systems HN Series humidity / temperature transmitter (BACnet MS/TP)
Greystone HN series humidity and temperature transmitters with BACnet MS/TP and an optional relay.
Also known as: HN, HNXXXBAC, Greystone HN humidity sensor - Humidity / temperature sensor with condensation monitoring
Greystone Energy Systems HTX1 Series rough duty RH / temperature transmitter (BACnet MS/TP)
Greystone HTX1 series rough-duty RH/temperature transmitters (PICS model DP0011) with optional pipe-temperature condensation probe, digital input and relay, using BACnet MS/TP.
Also known as: HTX1, HTX1XXXBAC, DP0011, NPI-56, Greystone rough duty sensor - Room temperature / humidity sensor
Greystone Energy Systems NTRC Series temperature / humidity room sensor (BACnet MS/TP)
Greystone NTRC series network room sensors (temperature, optional RH, setpoint, fan switch, override, relay and digital input) with BACnet MS/TP.
Also known as: NTRC, NTRCXXXBAC, STAT, Greystone NTRC network room sensor - Particulate matter (PM2.5 / PM10) sensor
Greystone Energy Systems PM Series particulate matter transmitter (BACnet MS/TP)
Greystone PM series particulate transmitters for room, duct and outdoor mounting (PMRMC, PMDT, PMOS) with BACnet MS/TP.
Also known as: PM Series, PMRMC, PMDT, PMOS, PMXXXBAC, Greystone particulate sensor - Room differential pressure sensor / monitor
Greystone Energy Systems RPC Series room pressure sensor (BACnet MS/TP)
Greystone RPC series room pressure monitors with local alarm buzzer and BACnet MS/TP.
Also known as: RPC, RPCXXXBAC, Greystone room pressure monitor - Ultra-low differential pressure sensor / transducer
Greystone Energy Systems UP Series ultra-low pressure transducer (BACnet MS/TP)
Greystone UP series ultra-low differential pressure transducers with BACnet MS/TP.
Also known as: UP, UPB, UPXXXBAC, Greystone ultra low differential pressure - VOC air quality sensor
Greystone Energy Systems VOC Series air quality transmitter (BACnet MS/TP)
Greystone VOC series room air quality transmitters (VOC with RH and temperature) with BACnet MS/TP and optional relay.
Also known as: VOC Series, VOCXXXBAC, Greystone VOC sensor, Greystone TVOC transmitter
Source: IAQRM Series Multi Sensor - Setup Guide BACnet Communication · SG-IAQRMXXXBAC-001 · rev. 03/23. Object names, instances and units are reproduced as published; descriptions are our own.