Lufft SHM31 User Manual

Communication in SDI-12 mode
46 Snow depth sensor SHM 31, V2.1
10.7. Additional measuring commands
With the additional measuring commands
aM1! … aM2!
aMC1! … aMC2! (M command, data transfer with CRC)
aC1! … aC2!
aCC1! … aCC2! (C command, data transfer with CRC)
additional measured values can be retrieved.
As with the basic data, a maximum of 9 measured values can be retrieved with an M command;
20 places are available with C commands.
The buffer assignment documented below is therefore structured such that buffers D0 and D1 are
allocated to the respective M command. If more measured values are available for the sensor
type, the buffers D2 to D4, if applicable, are also allocated to the corresponding C command.
M1 / C1 Angles M: 6 values C: 6 values
M2 / C2 Flags M: 7 values C: 7 values
Measurand
UMB-Channel
Min
Max
Unit
Buffer ‘0’
Run time
4007
0
9999999
s
Tilt angle (cur)
500
-180,0
180,0
°
X angle (cur)
504
-180,0
180,0
°
Buffer ‘1’
Y angle (cur)
505
-180,0
180,0
°
Z angle (cur)
506
-180,0
180,0
°
Tilt angle reference (cur)
510
-180,0
180,0
°
Table 7: SDI-12, additional values (M1 / C1: Angles) configured in metric or in US units
Measurand
UMB-Channel
Min
Max
Unit
Buffer ‘0’
Run time
4007
0
9999999
s
snow depth (cur)
600
-16000.0
16000.0
mm
snow flag (cur)
700
0
1
code
fogging flag (cur)
710
0
1
code
signal normalized
800
0
255
-
Buffer ‘1’
distance
650
-500.0
21000.0
mm
SHM31 error
4100
0
255
code
Table 8: SDI-12, additional values (M1 / C2: Flags) configured in metric units. The fog flag is not calculated at present.

Lufft SHM31 Specifications

General

Brand	Lufft
Model	SHM31
Category	Accessories
Language	English