Tektronix MSO54, Programmer'S Manual

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Status and Events
Example of Acquiring
and Measuring a
Single-Sequence
Waveform
For example, a typical application might involve acquiring a single-sequence
waveform and then taking a measurement on the acquired waveform. You could
use the following command sequence to do this:
/** Set up conditional acquisition **/
ACQUIRE:STATE OFF
DISPLAY:WAVEVIEW1:CH1:STATE 1
HORIZONTAL:RECORDLENGTH 1000
ACQUIRE:MODE SAMPLE
ACQUIRE:STOPAFTER SEQUENCE
/** Acquire waveform data **/
ACQUIRE:STATE ON
/** Set up the measurement parameters **/
MEASUREMENT:MEAS1:TYPE AMPLITUDE
MEASUREMENT:MEAS1:SOURCE CH
1
/** Take amplitude measurement **/
MEASUREMENT:MEAS1:RESUlts:CURRentacq:MEAN?
The acquisition of the waveform requires extended processing time. It may not
fi nish before the oscilloscope takes an amplitude measurement (see the following
fi gure). This can result in an incorrect amplitude value.
Figure 3-7: Command Processing Without Using Synchronization
To ensure the oscilloscope completes waveform acquisition before taking the
measurement on the acquired data, you can synchronize the program using *WAI,
BUSY, *OPC, and *OPC?.
Figure 3-8: Processing Sequence With Synchronization
Example of Using the *OPC
Command
If the corresponding status registers are enabled, the *OPC command sets the
OPC bit in the Standard Event Status Register (SESR) when an operation is
complete. You achieve synchronization by using this command with either a
serial poll or service request handler.
MSO54, MSO56, MSO58, MSO58LP Programmer 3-9