Campbell Scientific AVW200-series Vibrating Wire Interfaces - Manual (Page 45)

AVW200-series 2-Channel Vibrating Wire Spectrum Analyzer Modules
When using the “Mcmm” terminal command, no other
method of measurement should be used or multiplexing will
get out of sequence and measurement errors will result.
Read more! Appendix D lists the fields in the public table and provides a
brief description of each. Appendix E provides a comprehensive list of
status table variables with brief descriptions.
6. Programming
6.1 AVW200 Instruction
If using SDI-12 to communicate with the AVW200, then use the
SDI12Recorder instruction to trigger and retrieve measurements
from the AVW200 (see Section 6.2, SDI-12 Measurements.)
When using the RS-232 (PakBus) or RF(PakBus) protocol, the datalogger is
programmed using the AVW200 instruction in CRBasic.
Please ensure that the AVW200 instruction is included in
LoggerNet. If using LoggerNet 3.4.1 or lower, the user needs to
download the most recent version of the operating system (OS) for
the datalogger. This installation installs the required CRBasic
files on the user’s computer so that the AVW200 instruction
shows up in the editor.
The AVW200 instruction is used to read measurements from one or more
vibrating wire sensors when the sensors are connected to the AVW200
channels directly or connected to a multiplexer that’s attached to the AVW200.
In addition to frequency, diagnostic information is returned for the sensor (see
the Dest parameter).
The datalogger program can run the AVW200 instruction in either the pipeline
mode (Section 6.1.1, Pipeline Mode) or sequential mode (Section 6.1.2,
Sequential Mode). In the pipeline mode, the first execution of the instruction
sets up the AVW200; subsequent execution intervals retrieve the data values. If
different beginning and ending frequencies are required to measure different
types of sensors, use multiple AVW200 instructions with different beginning
and ending frequencies specified in each instruction. The sequential mode
performs each instruction in sequence; waits for each instruction completion;
and then repeats this process for each execution interval. The minimum scan
rate for an AVW200 program is 2 seconds per sensor.
Syntax
AVW200 (Result, ComPort, NeighborAddr, PakBusAddr, Dest, AVWChan,
MuxChan, Reps, BeginFreq, EndFreq, ExVolt, Therm50_60Hz, Multiplier,
Offset, [Optional] AmpThreshold)
Result The Result parameter is a variable that indicates the success
or failure of the datalogger's communication attempt with
the AVW200. If more than one AVW200 is used and the
CAUTION
NOTE
NOTE
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