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LeveLine
®
Instruction Manual
10401-01026 Rev D
6.8. SDI-12 Measurement Commands
On reception of any Start Measurement, Additional Measurement, Start Concurrent
Measurement or Additional Concurrent Measurement command (with or without CRC
request), the LeveLine
®
will respond indicating a maximum time for the measurements to
be ready and the number of measurements that will be returned in response to subsequent
Send Data commands.
In response to the Start Measurement and Start Concurrent Measurement commands the
measurement time will be 1 second and the number of measurements will be 2. In
response to the Start Measurement and Start Concurrent Measurement commands the
measurement time will be 0 seconds and the number of measurements will be 0.
After receiving the response to a Start Measurement command, the data recorder should
wait for the LeveLine
®
to send a Service Request before requesting the measurements with
a Send Data command.
After a Start Measurement command & response, the data recorder may abort the
measurement by sending a command to another device (preceded by a break frame) or by
sending a command other than Send Data to the LeveLine
®
.
After receiving the response to a Start Concurrent Measurement command, the data
recorder should wait for the measurement time to elapse before requesting the
measurements with a Send Data command.
After a Start Concurrent Measurement command & response, the data recorder may abort
the measurement by sending a command other than Send Data to the LeveLine
®
. (The
data recorder may send commands to other devices on the SDI-12 bus without aborting a
concurrent measurement.)
If the data recorder sends any Send Data command to the LeveLine
®
not preceded by any
form of measurement start command or after aborting a measurement sequence, then the
response will not contain any data values.
Sequence initiated with Start Measurement command (Standard Probe):
Command
Response
<a>M!
or
<a>MC!
<a>0012<CR><LF>
<a>D0!
<a><temperature><pressure><CR><LF>
or
<a><temperature><pressure><crc><CR><LF>
Sequence initiated with Start Concurrent Measurement command (Standard Probe):
Command
Response
<a>C!
or
<a>CC!
<a>00102<CR><LF>
<a>D0!
<a><temperature><pressure><CR><LF>
or
<a><temperature><pressure><crc><CR><LF>
© 2019 Aquaread
®
Ltd.
www.aquaread.com
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