Reading Via Sdi-12 - Seametrics INW CT2X Instructions Manual

DIRECT READ MODBUS & SDI-12

Reading via SDI-12

Note: The default units setting for pressure is PSI. The default units setting for temperature is Celsius.
To change these, use the Direct Read Units in the Aqua4Plus/Aqua4Plus Lite Control Software. Note: Conductivity is
always returned in µS/cm, Salinity in PSU, and TDS in mg/L.
Addressing
Default SDI-12 Address: 0
SDI-12 Command Nomenclature
<a> = Sensor address
{crc} = SDI-12 compatible 3-character CRC
<cr> = ASCII carriage return character
<lf> = ASCII line feed character
highlighted values
indicate variable data
SDI-12 Commands
Sensor Identification
<a>I! <a>13 INWUSA CT2X 215ssssssssss<cr><lf>
Acknowledge Active, Address Query
<a>! <a><cr><lf>
?! <a><cr><lf>
Change Address
<a>A<b>! <b><cr><lf>
Request Measurement
<a>M! <a>0024<cr><lf>
<a>D0! <a>+22.0512+155.0127+155.2155+12.0512<cr><lf>
<a>M1! <a>0021<cr><lf>
<a>D0! <a>+22.0512<cr><lf>
<a>M2! <a>0021<cr><lf>
<a>D0! <a>+155.0127<cr><lf>
<a>M3! <a>0021<cr><lf>
<a>D0! <a>+155.0127<cr><lf>
<a>M4! <a>0021<cr><lf>
<a>D0! <a>12.0512<cr><lf>
<a>M5! <a>0021<cr><lf>
<a>D0! <a>+20.7862<cr><lf>
<a>M6! <a>0021<cr><lf>
<a>D0! <a>14700.9<cr><lf>
Seametrics • 253.872.0284
All SDI-12 requests consist
of a command followed by
a request for values. Some
software or equipment may
combine these, making the
second one unnecessary. Refer
to your software or equipment
documentation for details.
Page 18
CT2X INSTRUCTIONS
Request Response
<a>M1! <a>0021<cr><lf>
Address
Address
Command Time until
response
(in seconds)
Request Response
<a>D0! <a>+7.15863<cr><lf>
Address Address
Request for Returned
value(s)
values read
215
Note: will change to reflect current
firmware version.
ssssssssss = device serial number
Change address to <b>
Request all basic measurements
Read: temperature, conductivity (linear),
conductivity (nLFn), pressure
Request temperature measurement only
Read temperature
Request linear conductivity measurement only
Read linear conductivity
Request nLFn conductivity measurement only
Read nLFn conductivity
Request pressure measurement only
Read pressure
Request salinity measurement only
Read salinity
Request TDS measurement only
Read TDS
Carriage Return
Linefeed
# of values to
be returned
Carriage Return
Linefeed
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