Lufft SHM31 User Manual

Commissioning
26 Snow depth sensor SHM 31, V2.1
7.3.2. The SHM 31’s sensor parameters
To take full advantage of all the benefits the SHM 31 snow depth sensor has to offer, we
recommend taking a closer look at the parameters the sensor uses internally. As already
mentioned in the previous section, the ‘Device Settings’ menu contains a large number of
adjustable parameters and thus also a comprehensive tool for defining a measurement routine for
the sensor in advance. The purpose of the table below is to provide an overview of this menu’s
adjustable parameters.
Parameter name
Default value
Domain
Description
Device parameters
Device-ID
1
1 … 255
Sensor-ID, to be set when using more
than one sensor in the bus (e.g. UMB
or SDI-12)
Description
snow depth
sensor
max. char. 39
...
Station-ID
0
0 … 99999
Additional ID (optional)
Baudrate
19200
[1200, … , 57600]
Communication Baudrate.
Protocol
umb-binary
umb-binary, umb-
ascii 2.0,
sdi-12, modbus
The communication protocol used by
the sensor
Timeout for protocol change
[min.]
10
1 … 60
Duration after which the protocol is
being reactivated in the case of a
temporary changeover
RS485 Parity
8n1
8n1, 8e1, 7e1
(sdi-12), 8n2
Serial port parity setting
Imperial units for SDI-12
metric
metric, sdi-12 us-
units
...
UMB-ASCII 2.0
Automatic transmission
0
0 … 99
0 = polling mode, 1 = available data
telegram
Transmission interval [s]
60
0 … 65535
Processing rate for measurements
(calculation of snow depth, averages,
etc. and preparing the data string for
transmission)
Message start control character
2
0 … 127
Protocol start character
Message end control character
4
0 … 127
Protocol end character
Line break mode
crlf
cr, lf
Protocol line feed character
Decimal separator char.
46
0 … 127
Decimal mark character used
Parameter separator character
59
0 … 127
Parameter delimiter character used
Block separator character
58
0 … 127
Block delimiter character used
Parameter name
Default value
Domain
Description
Heater parameters
Operating mode of the window
heater
automatic
off, automatic,
defrost
Heater mode for the sensor window
Operating mode of the block
heater
automatic
off, automatic,
defrost
Heater mode for the sensor housing
Target temperature of the
window heater [°C]
20
-50 … 50
Mean target temperature of window
Target temperature of the block
heater [°C]
7.5
-50 … 50
Mean target temperature of housing

Lufft SHM31 Specifications

General

Brand	Lufft
Model	SHM31
Category	Accessories
Language	English