Lufft SHM31 User Manual

Communication over UMB-ASCII 2.0
Snow depth sensor SHM 31, V2.1 35
Command
UMB-ASCII 2.0
Standard
value
Read,
Write,
Command
Name Description
HWH 2,5 RW
HeaterWindowHysteresis
Hysteresis; temperature is
kept within this range in the
automatic heater mode
(“HBM“=1).
HDS C
HeaterDefrostStart
Start defrost mode
temporarily (with values
“HDP”, “HDR”, “HDB”, “HDW”
for both heaters (block and
window)).
HDE C
HeaterDefrostEnd
Stop the defrost mode and
switch
“HBM” and “HWM” back to
their previous values.
HDM 1 RW
HeaterDefrostMode
Defrost mode: 0=always off,
1=during sensor start (with
values “HDP”, “HDR”, “HDB”,
“HDW” for both heaters (block
and window)).
HDP 15 RW
HeaterDefrostPeriod Block
Defrost: duration of defrost
heating cycle in minutes for
the block heater.
HDR 15 RW
HeaterDefrostPeriod Window
Defrost: duration of defrost
heating cycle in minutes for
the window heater.
HDB 35 RW
HeaterDefrostBlock
Defrost: set temperature in °C
for the block heater.
HDW 25 RW
HeaterDefrostWindow
Defrost: set temperature in °C
for the window heater.
Table 10: ASCII parameters for heater control
Command
UMB-ASCII 2.0
Standard
value
Read,
Write,
Command
Name Description
LMM 0 RW
Laser Measurement Mode
Mode for laser measuring
time control:
0=automatic measurement
LMI 10000 RW
Laser Measurement Interval
Laser measuring interval in
milliseconds.
SIT 130 RW
Signal Intensity Threshold
Sets the signal threshold that
is used to activate the “snow
flag” in the data telegram.

Lufft SHM31 Specifications

General

Brand	Lufft
Model	SHM31
Category	Accessories
Language	English