Modbus CO2 Multi-Sensor Datasheet

Version 1.3

Document Reference No.: BRTSYS_000160 | Clearance No.: BRTSYS#094

1 Introduction

The Modbus CO2 Multi-Sensor is a true CO2 Sensor featuring four integrated sensors in a compact, low-profile design. It measures CO2, temperature, humidity, and ambient light. The device supports both flush mounting on ceilings and swivel mounting on walls. It is available in two versions: Basic and Pro.

1.1 Features

Integrated temperature, humidity, and ambient light sensors.
Measures CO2 up to 40000ppm.
CO2 measurement accuracy:
- Basic version: +/-50ppm (400-2000ppm)
- Pro version: +/-40ppm (400-5000ppm)
Measures temperature up to 60°C with an accuracy of ±1.5°C.
Measures humidity from 0 to 100% with an accuracy of ±9%RH.
Measures ambient light up to 100K Lux with an accuracy of ±15% Lux.
Implements the Modbus RTU protocol.
Low power consumption: 300mW.
Operating temperature range: 0°C to +60°C.
Supports Swivel mount and Flush mount options.

Visit brtsys.com/resources for more information.

Compliance marks: CE, FCC, UKCA, RoHS, REACH.

2 Part Numbers / Ordering Information

Part Number	Description
MS-1101-01A	Modbus CO2 Multi-Sensor, Temperature & Humidity Sensor & ALS Sensor
MS-1102-01A	Modbus CO2 Multi-Sensor Pro, Temperature & Humidity Sensor & ALS Sensor
MA-0101-01A	Modbus RS485-JST Cable (30cm)
LA-1701-01A	LDSBus Sensor Swivel Mount Set

3 Specifications

Category	Feature	Specification
Features	Sensors	CO2 Multi-Sensor/ CO2 Multi-Sensor Pro, Ambient Light Sensor, Temperature Sensor, Humidity Sensor
	Interface	RS485 Modbus RTU
	LED Indicator (RGB)	System Status Indicator (Refer to LED section)
	Mounting	Flush Mount - Fixed Angle Installation
	Mounting	Swivel Mount – Adjustable Angle Installation (requires LDSBus Sensor Swivel Mount Set)
Power	Modbus Voltage	9-24V DC Bus Power
	Device Input Voltage	5V DC
	Typical Power	112mW
	Max. Power	295mW
CO2 Sensor	Overall Sensing Range	0-40000 ppm
	Specified Range	400-2000 ppm (Basic) / 400-5000 ppm (Pro)
	Accuracy	± (50ppm+5% of Reading) (Basic) / ± (40ppm+5% of Reading) (Pro)
Ambient Light Sensor	Update Interval	5 seconds (minimum)
	Range	0.001 to 100K Lux
	Accuracy	±15%
Temperature Sensor	Range	-10°C to 60°C (14°F to 140°F)
	Accuracy	±1.5°C (±34.7°F)
	Resolution	0.1°C
Humidity Sensor	Range	0 to 100% RH
Humidity Sensor	Accuracy	±9% RH
Physical Characteristics	Color	White
	Housing	Polycarbonate
	Dimensions	Ø 62mm x H25mm (Flush) / Ø 62mm x H60mm (Swivel)
Environmental Limits	Operating Temperature	0 to 60°C
	Storage Temperature	-20 to 85°C
	Ambient Relative Humidity	5 to 95% (non-condensing)
Package Contents	Device	1x Modbus CO2 Multi-Sensor with Flush Mount
	Wire Assembly	1x Modbus RS485-JST Cable(30cm)
	Self-Tapping Screws	2x M3*16mm (Thread)
	Optional Mounting Accessories	1x Swivel mount bracket

4 FCC Compliance Statement

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:

These devices may not cause harmful interference, and
These devices must accept any interference received, including interference that may cause undesired operation.

NOTE: The equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If the equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

Re-orient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
Consult the dealer or an experienced radio/TV technician for help.

To maintain compliance with FCC's RF exposure guidelines, at least 20cm of separation distance between the device and the user's body must be always maintained.

FCC Radiation Exposure Statement

This device complies with FCC radiation exposure limits set forth for an uncontrolled environment and it also complies with Part 15 of the FCC RF Rules. This equipment must be installed and operated in accordance with the instructions provided, and the antenna(s) used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter. End-users and installers must be provided with antenna installation instructions and consider removing the no-collocation statement.

Caution

Any changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment.

FCC logo

5 Hardware Features

The Modbus CO2 Multi-Sensor features several key components:

CO2 Sensor: Measures carbon dioxide levels.
Temperature & Humidity Sensor: Measures ambient temperature and relative humidity.
Ambient Light Sensor: Measures ambient light brightness in lux.
System Status LED Indicator: Provides visual feedback on the device's status.
Flush Mount Bracket: Included for ceiling mounting.

Hardware Labels & Description

Label	Description
Temperature & Humidity Sensor	Measure Temperature and Humidity
CO2 Sensor	Measure Carbon Dioxide
Ambient Light Sensor	Measure the light brightness (lux)
System Status LED Indicator	Modbus status LED. Refer to section 10 for more details.

6 Sensor Configuration and Installation

For detailed configuration guidance, including device naming, address, and termination settings, please visit brtsys.com/resources/software/utility-tools to access the Modbus Configuration Utility guide.

6.1 Connection Diagram for Standard Modbus Power Supply

The diagram illustrates the connection of the Modbus Host Controller to multiple Modbus Devices using RS485 communication and power. A Cat5e/Cat6e RJ45 Twisted Pair Cable is used for the main network connection.

Setup Instructions:

Use a Cat5e/Cat6e RJ45 Twisted Pair Cable to connect the Modbus controller (Host) to the network for RS485 communication and power.
Connect each Modbus device to the network using either an RS485-JST cable or an RS485-RJ11 cable, as provided with the device.
BRTSys Modbus devices have built-in bus termination resistors. These resistors can be enabled or disabled using the BRTSys Modbus Configuration Utility. When installing the device as the last device on the bus, these terminations may be used to terminate the bus.

6.2 RS485-JST Cable(30cm)

The RS485-JST cable is used for connecting Modbus devices. It features a standard RS485 Modbus Interface on one end and a JST Connector on the other.

PIN Legend	Function
VIN	Modbus Input Voltage 9-24VDC
GND	Ground
GND	Ground
B	RS485-B
A	RS485-A

7 Mounting Instructions

The sensor can be mounted using either the default flush mount method or an optional swivel mount.

Ensure the device is configured using the Modbus Configuration Utility before mounting.

7.1 Flush Mount

The flush mount is the default setup. This method assumes a flat hollow surface behind the mounting area for cable concealment. The RS485-JST cable is accessed through an opening.

Steps to fix the flush mount:

Unlock the back cover by twisting the top cover counter-clockwise.
Make two holes in the back cover using the provided indentations as guides.
Prepare the ceiling and route the RS485-JST cable through the ceiling opening. Run the cable through the center hole of the back cover and fasten the back cover to the ceiling with self-tapping screws.
Attach the cable to the JST connector of the sensor.
Twist the front face clockwise to attach it to the back cover and lock it.

7.2 Swivel Mount

The swivel mount is an optional accessory that allows for adjustable angle installation.

Steps to fix the swivel mount:

Choose the mounting position on the wall and drill holes for the swivel mount.
Route and affix the RJ11-JST cable on the wall, potentially through a conduit, to the base of the swivel mount.
Break off one of the three cable entry locations on the base plate for cable routing.
Push the RS485-JST cable through the bottom hole of the swivel mount's bottom section.
Fasten the swivel mount to the wall using mounting screws, ensuring the cable sits in the cable entry slot.
Unlock the back cover by twisting the top cover counter-clockwise.
Connect the JST cable from the top section of the swivel mount to the JST connector on the back of the device.
Attach the device to the top section of the swivel mount.
Turn the device clockwise to secure it to the swivel mount.

The swivel mount allows for 30° tilt left/right and 360° rotation.

8 Modbus Registers

The following table details the Modbus registers for the device:

Parameter	Starting Address(1)	Quantity of Registers	Supported Function Code	Parameter Range and Description	Default
RS485 Termination(1)	0000H	1	0x03/0x10	1 to 126 0 - Termination OFF 1 - Termination ON	126
Baud Rate(1)	0001H	1	0x03/0x10	0 - 1200 bps 1 - 2400 bps 2 - 4800 bps 3 - 9600 bps 4 -19200 bps 5 - 38400 bps 6 -115200 bps	9600 bps
Parity(1)	0002H	1	0x03/0x10	0 – None 1 – Odd 2 - Even	Even
Status LED Enable(1)	0003H	1	0x03/0x10	0 – LED OFF 1 – LED ON	LED ON
Sensor Calibrated Date	0004H	1	0x03/0x10	Calibration date YYYYMMDD	N/A
Sensor Calibrated Const	0005H	2	0x03/0x10	0x20221203 Constant value = 0x0004	0x0004
Sensor Calibrated CO2	0007H	1	0x03/0x10	Offset value 400 to 65535ppm	N/A
CAL XOR Checksum Value	0008H	1	0x03/0x10	XOR Checksum from register 05H to 08H	N/A
Device UUID	0009H	8	0x03	MSxxxxxxxxxxxxyy where x is ASCII character and yy is 16-bit running number	N/A
Device Firmware Version	0026H	1	0x03	0xXXMN XX - Not concerned M - Major N - Minor	N/A
Device Part Number Reserved	002EH	1	0x03	Device ID	0x8011
CO2	002FH	1	0x03	400 - 2000 ppm	N/A
Temperature	0030H	1	0x03	-1000 to 6000 (-10.00°C to 60°C)	N/A
Humidity	0031H	1	0x03	0 to 9999 (0% to 99.99%)	N/A
Luminance Reset	0032H	2	0x03	0 to 100000 lux	N/A
Reserved	0033H	1	0x06	Write 1 to reset	N/A
Reserved	0150H	N/A	N/A	Reserved	N/A
Identify	0151H	1	0x06	Write 1 to start blinking the device @1Hz for 10 seconds	N/A

(1) This indicates that any updates to these communication/status register(s) will only take effect after the device has been rebooted.

9 Mechanical Dimensions

The sensor has a compact design with specific dimensions for flush and swivel mounting.

Top View: Diameter Ø62mm.
Side View (Flush Mount): Height 23mm, Diameter 62mm.
Mounting Holes (Flush Mount): Holes Ø3.66mm, spaced 43.96mm apart.
Side View (Swivel Mount): Height 56mm (base to sensor), total height including sensor 23mm.
Mounting Holes (Swivel Mount): Holes Ø3.5mm, spaced 58mm apart.

All dimensions are in millimeters.