OTT PLS - SDI-12 Commands and Responses; Standard SDI-12 Commands

6 SDI-12 Commands and Responses
6.1 Standard commands
All SDI-12 standard commands are implemented in the OTT PLS. The following SDI-12 standard commands are relevant for
the operation of the OTT PLS:
1)
depending to the setting of measuring time (aOXM)
2)
if measuring time (aOXM) is ≥ 3 seconds
Command Response Description
a
!
a
<CR><LF>
Confirmation active
a – sensor address; factory setting = 0
a
I!
a
l3ccccccccmmmmmm …
…
vvvxxxx<CR><LF>
Send identification
a – Sensor address
l3 – SDI-12 protocol version
cccccccc – manufacturer identification (company name)
mmmmmm – Sensor identification
vvv – Sensor version (firmware)
xxxxxx – Serial number
Answer OTT PLS = 013OTTHACHPLS000100123456
aAb! b<CR><LF>
Change sensor address
a – old sensor address
b – new sensor address
?! a<CR><LF>
Query sensor address
a – sensor address
aM!
atttn<CR><LF>
and after 1 … 60 second(s)
1
)
a<CR><LF>
Starting the measurement
a – Sensor address
ttt – Time in seconds until the sensor has
determined the measurement result
Answer OTT PLS = 001 … 060
1)
n – Number of measured values
Answer OTT PLS = 2
or 4
2)
a<CR><LF> – Service request
aD0!
a<value1><value2>…
…
<value3><value4><CR><LF>
Send data
a – sensor address
<value1> –
average
2)
level/pressure value
measured value formats:
m ➝ pbbbb.eee
cm ➝ pbbbbbbbb
ft ➝ pbbbbb.ee
mbar ➝ pbbbbb.ee
psi ➝ pbbbb.eee
<value2> – temperature value
measured value formats:
°C and °F ➝ pbbb.e
<value3>
2)
– minimum level/pressure value within
the actual measuring interval
measured value formats: see above
<value4>
2)
– maximum level/pressure value within
the actual measuring interval
measured value formats: see above
p – sign (+,–)
b – numbers (before the decimal point)
Output is without leading zeroes!
e – digits after the decimal point
aMC! atttn<CR><LF>
and after 2 seconds
a<CR><LF>
Start the measurement and request CRC (Cyclic Redundancy
Check). For details see command aM!.
The answer to the following aD0! command is extended
by a CRC value:
a<value1><value2><CRC><CR><LF>
13