Campbell Scientific AVW200-series Vibrating Wire Interfaces - Manual (Page 50)

AVW200-series 2-Channel Vibrating Wire Spectrum Analyzer Modules
detected. Therefore, the result variable for the first instruction would be zero
(indicating successful communication) and the result variable for the second
instruction would increment (indicating a failed communication). In the
pipeline mode this situation does not exist, so the result code variables can be
the same for multiple AVW200( ) instructions on a given communication port.
(1) When running in the sequential mode, programs that contain
multiple AVW200 instructions using the same COM port should
have different “Result” variables for each AVW200 instruction
(e.g. “Result1” and “Result2”) in order to detect and isolate any
communications errors for a given AVW200.
(2) If the AVW200( ) instruction is in a slowsequence, the mode
of operation is always forced to sequential mode.
Read more! Example programs of the sequential mode are provided in
Section 7.4.
6.2 SDI-12 Measurements
For our CR5000, CR10X, and CR23X dataloggers, an SDI-12 instruction must
be used to trigger and retrieve measurements from the AVW200. Our CRBasic
dataloggers (e.g., CR5000, CR1000, CR3000) use the SDI12Recorder
instruction, and Edlog dataloggers (i.e., CR10X, CR23X) use Instruction 105.
The SDI12Recorder instruction should only be run in the sequential mode.
When using SDI-12, multiplexers must be controlled by the datalogger.
Appendix G, CR10X Programming Example, describes Instruction 105 and
provides a CR10X program example.
6.2.1 SDI12 Recorder() Instruction
The values returned from the SDI12Recorder( ) instruction are different
depending on the SDI12 measurement command issued. The SDI12Recorder
instruction sends the command specified by the SDI12Command parameter as
(address)SDI12Command!. The AVW200 always returns six values.
Sytnax
SDI12Recorder ( Dest, SDIPort, SDIAddress, "SDICommand", Multiplier,
Offset )
The SDI12Recorder instruction has the following parameters:
Dest The Dest parameter is a variable in which to store the results
of the measurement. Dest must have enough elements to
store all the data that is returned by the SDI-12 sensor or a
'variable out of range' error will result during the execution
of the instruction.
NOTES
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