Lufft SHM31 User Manual

Communication in SDI-12 mode
50 Snow depth sensor SHM 31, V2.1
Example:
0XRES!
0XRESok<CR><LF>
10.11.3. End measurement command
The command ends the automatic snow depth measurement, e.g. for setting and calibration work.
Command: aXMEN!
Response: aXMENok<CR><LF>
If procedures that prohibit execution of the command are active,
aXMENbusy<CR><LF>
will be the response and the command will be ignored.
10.11.4. Start measurement command
The command starts the automatic snow depth measurement if it was disabled, e.g. for setting
and calibration work.
Command: aXMST!
Response: aXMSTok<CR><LF>
If procedures that prohibit execution of the command are active,
aXMSTbusy<CR><LF>
will be the response and the command will be ignored.
10.11.5. Laser on command
The command switches the laser on continuously, e.g. for setting the measuring point.
Command: aXLON!
Response: aXLONok<CR><LF>
If procedures that prohibit execution of the command are active,
aXLONbusy<CR><LF>
will be the response and the command will be ignored.
10.11.6. Laser off command
The command switches the laser that was previously switched on continuously off again.
Command: aXLOF!
Response: aXLOFok<CR><LF>
If procedures that prohibit execution of the command are active,
aXLOFbusy<CR><LF>
will be the response and the command will be ignored.
10.11.7. Calibrate offset and angle command
The command starts a measuring process to determine distances and angle. The determined
values are set as offsets / reference heights and angle correction values.
Command: aXARV!
Response: aXARVok<CR><LF>
If procedures that prohibit execution of the command are active,
aXARVbusy<CR><LF>
will be the response and the command will be ignored.

Lufft SHM31 Specifications

General

Housing material	Plastic
Humidity Range	0% to 100% RH
Humidity Accuracy	±2% RH
Mounting	Wall
Measurement Parameters	Temperature, Humidity
Output	RS-485
Power Supply	12 VDC to 24 VDC

Summary

Read Before Commissioning

Safety Instructions

Provides essential safety precautions for assembly, operation, and handling of the sensor.

Laser Safety and Classification

Details laser safety Class 2 compliance and exposure guidelines to prevent eye damage.

Item and Technical Data

Technical Data

Presents detailed specifications including measuring parameters, interfaces, operating conditions, and dimensions.

Device Description and Operation

Measurement Method Principles

Explains the phase measurement method utilizing laser pulses for distance measurement.

Assembly and Commissioning Introduction

Guides on sensor mounting, alignment, and initial setup procedures including zero measurement.

Sensor Assembly

Assembly Procedures

Details the physical mounting of the sensor on a mast using provided clamps and alignment procedures.

Device Connections

Connector Pin Assignment

Maps the interface cable cores to specific pins on the SHM 31 connector.

Data Interfaces

Lists the available communication interfaces: RS485, SDI-12, and RS232.

Commissioning the Sensor

Important Commissioning Information

Highlights key points for successful commissioning, including software usage and laser safety.

UMB ConfigTool.NET Setup

Introduces the UMB ConfigTool.NET software for sensor configuration, firmware updates, and data acquisition.

UMB-ASCII 2.0 Communication

Communication Syntax

Defines the grammatical structure and components of UMB-ASCII 2.0 data telegrams.

UMB Communication Protocols

Measuring Channels Overview

Lists the available UMB channels with their measured variables and units.

Binary Protocol Communication

Explains how to communicate using the UMB binary protocol, including data frames and addressing.

UMB Binary Protocol Status and Error Codes

Lists and explains status and error codes encountered in UMB binary protocol communication.

SDI-12 Mode Communication

SDI-12 Settings and Configuration

Guides on configuring the sensor for SDI-12 communication via ConfigTool.NET or ASCII commands.

Query Measured Value Parameters

Describes the command for querying measured value parameters and their codes.

Switching Commands

Introduces manufacturer-defined SDI-12 commands used to trigger specific procedures.

Calibrate Offset and Angle

Describes the command to start a process for determining and setting distance and angle offsets.

Parameter Setting Commands

Introduces commands for reading and setting sensor parameters in SDI-12 mode.

Modbus Mode Communication

Modbus Functions Overview

Lists the implemented Modbus functions applicable to the SHM 31-UMB.

Read Input Registers Function (0x04)

Details the function for reading measured values and status information via input registers.

Signal Quality Check

Application of Target Plates

Explains how to use target plates to check the sensor's signal intensity and reflectivity response.

Service, Maintenance, and Support

Firmware Update Procedure

Guides on how to update the sensor's firmware using the UMB ConfigTool.NET software.

Troubleshooting Sensor Faults

Lists common errors, their possible causes, remedies, and specific error codes.

Technical Support and Repair

Offers contact information for obtaining technical assistance and repair for the sensor.