OTT CBS, Руководство по эксплуатации, Страница: 22 / 28

9 SDI-12 Commands and Response
9.1 Standard commands
The following SDI-12 standard commands are implemented in the OTT CBS:
Command Response Description
a! a<CR><LF>
Acknowledge active
aI! allccccccccmmmmmm…
Send Identification
…vvvxxxx<CR><LF>
OTT CBS Response = 13OTT HACH CBS107
aAb! b<CR><LF>
Change Address
?! a<CR><LF>
Adress Query
aM! atttn<CR><LF>*
Start measurement in normal mode.
The measured values are output as follows:
D0: Level [m]; resolution: 0,001 m
D1: Level [cm]; resolution: 1 cm
D2: Level [ft]; resolution: 0,01 ft
D3: Pressure [mbar]; resolution: 0,1 mbar
D4: Pressure [psi]; resolution: 0,001 psi
D5: Temperature [°C]; resolution: 0,1 °C
D6: Status (see command
aV!
)
aD0! a<wert<CR><LF>
Send data.
The answer looks as follows:
a = device address <values> = pd.d = +1,000
(level value – maximum of 9 characters per value and
35 characters per query). If several measured values
are queried, it may be necessary to continue with fur-
ther queries, e.g.
aD1!
.
aV! atttn<CR><LF>*
Start verification.
The verification lasts 1 second and provides a value
representing the test result:
D0: a+0<CR><LF>:
no error
D0: a+1<CR><LF>: level too low (< 5 cm)
D0: a+2<CR><LF>: overload (measuring range
exceeded)
D0: a+4<CR><LF>: power supply voltage too
low
D0: a+8<CR><LF>: pump motor overloaded
D0: a+16<CR><LF>: watchdog error
D0: a+256<CR><LF>: data memory defective
D0: a+512<CR><LF>: data bus defective
D0: a+1024<CR><LF>: analog converter defective
D0: a+2048<CR><LF>: measuring cell defective
more than one error:
sum of errors
Note:
Messages 256 to 2048 signify hardware problems
that can only be rectified by the OTT Repaircenter (see
chapter 11). In this case, send your OTT CBS to us.
Message 16 means that your unit has been restarted.
No intervention is necessary.
* The answers consist of the following:
a = device address
ttt = 001 = time in seconds until the sensor is ready again at the latest
n = 5 = number of measured values
More information on the SDI-12 standard commands can be found in the document SDI-12; A Serial-Digital Interface Stan-
dard for Microprocessor-Based Sensors; Version 1.3 (see Internet page www.sdi-12.org).
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