GW-LS-RA2 80GHz Radar Level Sensor Guide

Version: V1.2

Version	Update Content	Date
V1.0	Initial release	2022‑01‑07
V1.1	Added dual‑axis adjustable bracket; revised dimension parameters	2023‑10‑08
V1.2	Modified wire color definition	2024‑10‑08

1. Product Overview

The GW‑LS‑RA2 is an 80 GHz millimeter‑wave radar level sensor adopting FMCW radar principle. It supports maximum measuring distance up to 30 m with 5 GHz working bandwidth for high‑accuracy measurement. With IP67 ingress protection, it is suitable for outdoor field environments.

The sensor is equipped with an RS485 interface and supports standard Modbus protocol. Custom non‑standard protocols are available. Typical application scenarios include hydrological monitoring, sewage treatment, smart agriculture and object distance detection.

2. Technical Specifications

Basic Parameters

Item	Parameter	Note
Model	GW‑LS‑RA2
Power Supply	7~28 VDC
Operating Current	Average: 10 mA; Peak: 40 mA
Power‑on Time	20 s
Ingress Protection	IP67
Overall Dimension	6060133 mm (with bracket)
Operating Temperature	-40~80 ℃
Humidity	0~100 % RH (non‑condensing)
Zero Reference	Bottom of housing as zero point (software‑configurable)

Measurement Parameters

Item	Parameter	Note
Measuring Range	0.1‑15 m / 0.1‑30 m
Measurement Accuracy	±1 mm	Tested on hard metallic reflective surface
Radar Frequency	76G~81 GHz
Beam Angle	6°
Measurement Modes	Empty‑height mode, Liquid‑level mode

Communication Parameters

Item	Parameter	Note
Physical Interface	RS485	Baud rate: 9600
Protocol	Modbus‑RTU	Custom non‑standard protocol supported

3. Power Supply Instructions

The device accepts DC input from 7 V to 28 V. It uses an internal DC‑DC power supply: higher input voltage yields lower operating current while keeping overall power consumption roughly constant.

For battery‑powered low‑power applications: it is recommended for the host controller to power‑on the sensor before sampling and cut off power after data reading to reduce system power consumption.

4. Operating Characteristics

Factory default parameters are optimized for static level measurement for slowly‑changing targets. When target position changes abruptly, the sensor requires a certain period to synchronize to new measured values. Faster response can be enabled via configuration parameters, which shall be notified before shipment. Higher response speed will partially sacrifice measurement accuracy.

The sensor responds to Modbus commands immediately after power‑on. Nevertheless, radar internal data needs time to stabilize with a typical settling time of 5 s. For low‑power host controllers, read measured data 5 seconds after power‑on to obtain valid readings.

Default algorithm is tuned for slowly‑varying targets such as water surface. When target distance changes drastically (e.g. radar switches from facing ground to ceiling, or an obstacle is placed underneath), internal algorithm may take a much longer time (typical 30 s) to update output. You may power‑cycle the unit during testing to speed up valid value acquisition.

If fast‑moving targets need to be measured, please clarify your required response time before ordering.

The sensor evaluates echo signal strength internally. Measurements will be discarded if echo strength falls below threshold. This rarely occurs under normal conditions. Host controllers can read real‑time echo strength via Modbus for on‑site installation diagnosis.

Raw radar output is empty‑height value (distance from sensor to target). The sensor can output raw empty‑height or converted liquid‑level value. After writing installation reference baseline to register, output = reference value − empty‑height value.

• Reference value = 0: output raw empty‑height;
• Reference value > empty‑height: output difference (reference − empty‑height);
• Reference value < empty‑height: output = 0.

5. Protocol Description

Default serial settings: 9600 baud, 8 data bits, 1 stop bit, no parity, Modbus‑RTU. Custom protocol adaptation is supported for drop‑in replacement without host‑side logic modification.

5.1 Device Address

• Factory default address: 1, configurable via Modbus commands.
• If address is unknown: use broadcast address 0 for reading. Only one device shall be connected on bus when address 0 is used.

5.2 Register Address Map

Function	Register Address	Read‑Write(Y/N)	Description
Level reading (mm)	0x0000	N	Unit: mm, max 65535 mm
Level reading (cm)	0x0001	N	Unit: cm, max 65535 cm
Device Address	0x1000	Y	0~255
Application Type	0x1001	Y	0‑River; 1‑Tide; 2‑Well; 3‑Demo; 4‑Water Tank
Measurement Type	0X1002	Y	0‑Level(default); 1‑Empty‑height; 2‑Distance
Empty‑height Reference Setting	0X1003	Y	Unit: mm
Zero‑point Offset Correction	0X1004	Y	Unit: mm
Analysis Mode	0X1005	Y

5.3 Communication Examples

Read level data (2000 mm)

Transmit	01 03 00 00 00 01 84 0A
Response	01 03 02 07 D0 BB E8

Modify device address (from 01 to 02)

Transmit	01 06 10 00 00 02 0C CB
Response	01 06 10 00 00 02 0C CB

Set empty‑height reference value (5000 mm)

Transmit	01 06 10 03 13 88 70 5C
Response	01 06 10 03 13 88 70 5C

5.4 Parameter Configuration Guide

Generic serial debugging tools can send Modbus frames for reading and configuration. It is recommended to use Gewuiot Online Modbus Tool for visual operation without deep knowledge of underlying Modbus frames.

1. Select official template: GW‑LS‑RA2 Radar Water Level Gauge;
2. Serial port parameters: 9600‑8‑N‑1;
3. Connect to the physical COM port of your computer;
4. Start cyclic polling;
5. To write parameters: input value in corresponding register entry and click write‑confirm.

Example for reference baseline setting: Current empty‑height = 1022 mm, set reference = 5000 mm, output = 5000‑1022 = 3978 mm. Empty‑height setting register address: 0X1003 (decimal 4099), use function code 06 to write value 5000. Restore factory defaults: write value 1 to register 0X0107 (decimal 263). Change device address: write target address to register 0X1000 (decimal 4096). Re‑establish serial connection afterwards.

6. Cable Wiring Definition

Wire Color	Signal
Red	VCC
Black	GND
Yellow	RS485+
Green	RS485‑

7. Outline Dimensions

Overall dimension with dual‑axis adjustable bracket: 60*60*133 mm

Insert mechanical drawing while exporting to Word / PDF.

8. Packing List

No.	Item	Remarks
1	Sensor Main Unit
2	Dual‑Axis Adjustable Bracket

Note: Hard‑copy paper manual is not included by default. Contact manufacturer if printed copy is required.