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Verification and Reading current Set-up
There are 2 options to read the tipping bucket configuration
1.
aXBm (1XB4! in our examples) command which returns
a+s+o+p+t+v+i<CR><LF> or
a+NC<CR><LF> if Mm is not set to measure rain-fall.
2.
aXGm (1XG4) command if you are not sure whether Mm measures rainfall or something
else. Refer to appendix A for description of the XGm command.
Count Measurement
Counts from an input signal can be measured on channel DIN or AN4. Channel DIN can be set-up to have
internal pull-up or pull-down, but channel AN4 has no internal pull-up or pull-down devices.
SDI-12 set-up command
To configure for Count measurement or change a parameter (other than default), you can use the SDI
command
aXCm+s+o+p+t+v+i!
where,
a: SDI-address of module
m: Measurement number (M command number : 1…9)
s: Slope (default is 1.00) It is a multiplier to convert number of counts to an engineering unit
o: Offset (default is 0.00). A constant value to be added to the result after adjusting it with Slope
p: Measurement channel, „D‟ for DIN and „4‟ for AN4. (Default is D, i.e. DIN)
t: Initial count. Default is 0
v: switching de-bounce time. Default is 0.000, i.e. 0mS Note: The de-bounce time limits the maximum
frequency of the signal which can be measured, meaning, if de-bounce time is set to 1mS, counts for a 2
KHz signal will be filtered out since the time between input transitions is less than 1mS.
i: L=Enable internal pull-down, H=Enable internal pull-up, O=floating (no pull-up or pull-down). This
parameter is valid only when channel is D. Otherwise it is ignored and taken as O. (by default, it is O for
both the channels)
Examples
Consider configuring M4 to measure counts from a module at SDI-12 address 1
To configure M4 to measure counts with factory default parameters, use
1XC4+FD!
Which will configure the M4 command in the module at SDI-12 address 1 to return as the
measurement, the count of the number of pulses seen since the issuance of the configuration
command. The measurement will be performed with the factory defaults of: slope=1.00, offset=0,
channel DIN with no pull-up or pull-down, initial-count=0, de-bounce-time=0mS.
To set the offset (current counts) to 2.4 and leave all other parameters unchanged (default if never
programmed), use
1XC4+X+2.4!
To set M4 to measure counts with initial counts equal to 200 and all other parameters set to factory
default, use two commands
1XC4+FD! followed by 1XC4+X+X+X+200! or one command
1XC4+0.02+0+D+200+FD! if you need to specify parameters before initial-counts
In the example where all parameters are specified as „X‟ except for the 2
nd
parameter, the „X‟ means
“leave the parameter unchanged” (factory default in this example).
