Lufft SHM31 User Manual

Communication over UMB-ASCII 2.0
Snow depth sensor SHM 31, V2.1 33
Command
UMB-ASCII 2.0
Standard
value
Read,
Write,
Command
Name Description
the telegram are converted to the new
units. The scaling factor is defined in
the range [0;40000].
PRT RW Protocol
User-Interface RS485/SDI-12 (0=UMB,
9=ASCII2.0, 3=SDI-12, 5=Modbus-
RTU, 6=Modbus-ASCII)
ASC MST RW AutoStartCommand
Boot up mode of the sensor, e.g.
MST=start snow depth measurement.
Current values: ASC := {MST , LON}
STB - C NA
Function not yet implemented.
LON C Laser On
Switch laser into blinking mode for
alignment
LOF C Laser Off
Switch laser off after LON command.
To start the measurement, send MST
afterwards.
RST C Reset
Reset immediately.
RST=<Value> C
Reset in <Value>
ms
Reset after<Value> ms
RSD C
Reset default
values
Reset to default values
UMB
C
Switch to UMB temporarily
CAC 10 RW
channel_average_c
ounts
Number of measurements used to
calculate the averaged UMB channel
values (*_avg) and for the min and max
values.
Table 8: ASCII parameters for settings and control
Command
UMB-ASCII 2.0
Standard
value
Read,
Write,
Command
Name Description
ARV C AdjustmentReferenceValues
Measures the current
distance and tilt angle and
sets the adjustment offset
“AOF“ and the adjustment
angle “AAN“.
ARH C AdjustmentReferenceHeight
Measures the current
distance and determines the
adjustment offset “AOF“ using
the currently set adjustment
angle.
AOF 0 RW AdjustmentOffset
Offset (distance to surface
(vertical)), see “ARV“.
AAN 0.0 RW AdjustmentAngle
Installation angle (0.0°
corresponds to vertical
measurement towards the
ground surface).

Lufft SHM31 Specifications

General

Brand	Lufft
Model	SHM31
Category	Accessories
Language	English