Apogee SN-500-SS, Руководство по эксплуатации продукта

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Table 8-1: SN500SS SDI-12 commands
SI-12 command
( a is the sensor address)
Values returned or function Units
a
M!
, a
C!
,
a
MC!
, or a
CC!
1. Incoming short-wave (SW) radiation
2. Outgoing SW radiation
3. Incoming long-wave (LW) radiation
4. Outgoing LW radiation
W m
–2
W m
–2
W m
–2
W m
–2
a
M1!
, a
C1!
,
a MC1! , or a CC1!
1. Net SW
2. Net LW
3. Total Net Radiation
W m
–2
W m
–2
W m
–2
a
M2!
, a
C2!
,
a
MC2!
, or a
CC2!
1. Voltage signal for incoming LW
2. Sensor body temperature for
incoming LW
3. Voltage signal for outgoing LW
4. Sensor body temperature for
outgoing LW
mV
°C
mV
°C
a
M4!
, a
C4!
,
a MC4! , or a CC4!
Albedo W m
–2
a
XHON!
Turn heater on
a
XHOFF!
Turn heater off
?!
Returns the SDI-12 Address
See SDI-12 sensor support (p. 16) for additional commands and details of the SDI-12 protocol.
8.2 Long cables
The SDI-12 standard specifies the maximum total cable length to be 61 m (200 ft). Digital data
transfer eliminates offset errors due to cable lengths. However, digital communications can break
down when cables are too long, resulting in either no response from the sensor or corrupted
readings.
SN500SS Net Radiometer 12