User guide

H-3521 SDI-12 Command and Response Protocol 5-15
5.14 Extended Read Measure Rate and Write Measure Rate
When the H-3521 is put in power mode 3 it makes continuous measurements based on a measure
rate. This command is for reading/writing that measure rate value. The measure rate range is 0-
255 minutes. When the user sets the measure rate to 0 then the H-3521 makes continuous
measurements as fast as the H-3521 will measure, which is about 6 seconds by default. The
factory default is 1 minute measure rate.
Command Response Description
"aXRMR!" “a0011<cr><lf>" Read Measure Rate
"aXWMRnnn!" “a0021<cr><lf>" Write Measure Rate
Where: a is the sensor address ("0-9", "A-Z", "a-z", "*", "?").
XRMR are upper case characters.
XWMR are upper case characters.
nnn is the rate in minutes that the sensor will update all outputs.
Example of a H-3521 Extended "Read Measure Rate" command:
Command Response Time Values Description
"aXRMR!" "a0011<cr><lf>" 1 sec 1 Read Measure Rate
Command Response Description
"aD0!" "a+1<cr><lf>" Measure Rate = 1 minute
Example of a H-3521 Extended "Write Measure Rate" command:
Command Response Time Values Description
"aXWMR2!" "a0021<cr><lf>" 2 sec 1 Write Measure Rate
Command Response Description
"aD0!" "a+2<cr><lf>" Measure Rate = 2 minutes