Lufft SHM31 - Page 4

Snow depth sensor SHM 31, V2.1
9.3.4. Example of a binary protocol query ........................................................................................................ 39
9.3.5. Status and error codes in the UMB binary protocol ................................................................................ 40
9.3.6. CRC calculation ..................................................................................................................................... 41
10. Communication in SDI-12 mode ............................................................................................................................. 42
10.1. Connector pin assignment ................................................................................................................................ 42
10.2. Settings for using SDI-12 .................................................................................................................................. 42
10.3. Exiting SDI mode .............................................................................................................................................. 42
10.4. Command overview .......................................................................................................................................... 43
10.5. Setting the address ........................................................................................................................................... 44
10.6. Measured data telegrams ................................................................................................................................. 44
10.6.1. Example: C and M queries of the SHM 31-UMB .................................................................................... 45
10.6.2. Buffer assignment – basic data – SHM 31-UMB .................................................................................... 45
10.7. Additional measuring commands ...................................................................................................................... 46
10.8. Device identification telegram ........................................................................................................................... 47
10.9. Telegram verification ......................................................................................................................................... 47
10.10. Query measured value parameter command (SDI-12 v1.4) ............................................................................ 48
10.11. Switching commands ....................................................................................................................................... 49
10.11.1. Unit system changeover command ........................................................................................................ 49
10.11.2. Device reset command ........................................................................................................................... 49
10.11.3. End measurement command ................................................................................................................. 50
10.11.4. Start measurement command ................................................................................................................ 50
10.11.5. Laser on command................................................................................................................................. 50
10.11.6. Laser off command................................................................................................................................. 50
10.11.7. Calibrate offset and angle command ...................................................................................................... 50
10.11.8. Calibrate offset command ...................................................................................................................... 51
10.11.9. Switch on defrost heating cycle command ............................................................................................. 51
10.11.10. Switch off defrost heating cycle command ............................................................................................. 51
10.12. Parameter setting commands .......................................................................................................................... 51
10.12.1. Retrieving the current parameter setting ................................................................................................ 51
10.12.2. Setting the parameter setting ................................................................................................................. 52
11. Communication in Modbus mode ........................................................................................................................... 53
11.1. Modbus connection and communication parameters ........................................................................................ 53
11.2. Addressing ........................................................................................................................................................ 53
11.3. Modbus functions .............................................................................................................................................. 53
11.3.1. 0x03 Read Holding Registers, 0x06 Write Single Register, 0x16 Write Multiple Registers function ...... 53
11.3.2. 0x04 Read Input Registers function ....................................................................................................... 55
12. Checking the signal quality ..................................................................................................................................... 59
12.1. Application ........................................................................................................................................................ 59
13. Service, maintenance and technical support ......................................................................................................... 61
13.1. Firmware update ............................................................................................................................................... 61
13.2. Maintenance ..................................................................................................................................................... 61
13.3. Faults ................................................................................................................................................................ 63
13.3.1. Possible indications of error on the snow depth sensor ......................................................................... 63
13.3.2. Potential interferences that may affect correct functioning ..................................................................... 63
13.3.3. Error codes ............................................................................................................................................. 63
13.4. UMB status codes ............................................................................................................................................. 64
13.5. Disposal information – within the EU ................................................................................................................ 65
13.6. Disposal information – outside the EU .............................................................................................................. 65
13.7. Repair / maintenance ........................................................................................................................................ 65
13.8. Technical support.............................................................................................................................................. 65