VXI VT1422A - Manual (Page 90)

88 Programming the VT1422A & VT1529A/B for Remote Strain Measurement Chapter 3
Voltage Conversion
Command Sequence
Below is an example VXIplug&play command sequence. Note that this is
not executable; it has been simplified for easier reading. The C++ example
source file (voltseq.cpp) is on the CD supplied with the instrument.
View the readme.txt file provided with the VXIplug&play driver for
example program file location.
Figure 3-18. Converting Bridge Voltage Measurements to Strain
Readings returned in voltage
Retrieve readings from
FIFO and/or CVT
Trigger event for each pass
through Scan List
Set up Trigger System to scan
strain bridge channels
Set up the analog input Scan List
Measure unstrained bridge output
voltages and retrieve from FIFO
Measure bridge excitation
voltages and retrieve from FIFO
Enable excitation voltage
to the strain bridges
Set bridge configuration switches SENSe:STRain:BRIDge[:TYPE]
SENSe:STRain:EXCitation:STATe
MEASure:VOLTage:EXCitation?
SENS:DATA:FIFO:PART?
MEASure:VOLTage:UNSTrained?
SENSE:DATA:FIFO:PART?
ROUTe:SEQuence:DEFine
TRIG:SOURce, TRIG:COUNt, ARM:SOURce
TRIG:TIMer
Set up Sample Timer for best
channel-to-channel scan rate
Initiate Trigger System
SAMPle:TIMer
INITiate[:IMMediate]
TRIG[:IMM], *TRG (if TRIG:SOUR HOLD),
EXTernal trig, TTLTRGn signal, or TRIG:TIMer
SENSe:DATA:FIFO:..., SENSe:DATA:CVTable?
Set Input Filter on VT1529A/B INPut:FILTer:FREQuency and INPut:FILTer:STATe
Post-process unstrained, excitation,
gage factor, and strained values
to calculate strain
SENSe:FUNCtion:VOLTage