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m: Measurement number (M command number : 1…9)
p: Measurement channel (1:AN1, 2:AN2, 3:AN3 4:AN4 and V:Vref)
n: Reference channel. (1:AN1, 2:AN2, 3:AN3 4:AN4, V:Vref and G:ground)
For example, 1XR3+2+3! will configure the M3 command for the module at SDI-12 address “1” to measure
the ratio of voltage AN2 with respect to AN3. If AN3 is 4Volts and AN2 is 3Volts, then the returned value
will be 0.75 since AN2 is ¾ of AN3. The other parameters (slope, offset, Vref warm-up time, SW‟D voltage,
input type and gain) will be left unchanged.
Tipping-Bucket Measurement
To measure rain-fall, connect tipping bucket between channels DIN (pulled-up) and ground, and issue SDI
command
aXBm+FD!
where,
a: SDI-address of module
m: Measurement number (M command number : 1…9)
For example, 1XB4+FD! will configure the M4 command in the module at SDI-12 address “1” measure
rainfall with the factory defaults which are: slope=0.01, offset=0, channel DIN with internal pull-up, initial-
count=0, de-bounce-time=20mS. Note: This takes the module out of a strictly standby mode in that it is
continuously accumulating tips. Measurements return the current accumulation total.
Counts Measurement
To measure Counts on channel D, issue the SDI-12 command
aXCm+FD!
where,
a: SDI-12 address of module
m: Measurement number (M command number : 1…9)
For example, 1XC4+FD! will configure the M4 command in the module at SDI-12 address “1” to measure
the number of counts with the factory defaults which are: slope=1.00, offset=0, channel DIN without a pull-
up or pull-down, initial-count=0, de-bounce-time=0mS. Note: This takes the module out of a strictly standby
mode in that it is continuously accumulating counts. Measurements return the current accumulation total.
Frequency Measurement
To measure Frequency on channel D, issue the SDI-12 command
aXFm+FD!
Where,
a: SDI-address of module
m: Measurement number (M command number : 1…9)
For example, 1XF4+FD! will configure the M4 command in the module at SDI-12 address “1” to measure the
frequency of signal on DIN channel with factory defaults for slope=1.00, offset=0 without any pull-up or pull-
down on the input, de-bounce-time=0mS, no switched voltage on SWD port.
Period Measurement
To measure period of the signal on channel D, issue the SDI-12 command
