Filter
Top Products
3 - 8 USING THE COMBISCOPE INSTRUMENTS
3.3 Measuring Signal Characteristics
As explained in section 3.2.1 "Measurement instructions", the measurement
instruction set is a new approach in the remote operation of programmable
instruments. This instruction set allows you to request a particular characteristic
of the input signal. The CombiScope instrument then chooses the best possible
settings, executes the requested task, and returns the desired result.
Within the measurement instruction set, different programming levels can be
distinguished. The highest level is the easiest to use, but the trade-off is less
flexibility. Lower levels provide more flexibility by offering more control over the
instrument functionality. This requires more knowledge about the remote
operation of your instrument.
The measurement instructions specify a particular task in terms of the expected
signal and the desired result. The instructions refer to the signal characteristics of
the signal being measured. This makes them independent from the
implementation of the instrument functions. For example, when the instruction
MEASure:FREQuency? is executed, it is not important whether this frequency is
measured by precisely counting the signal period, or if it is calculated from a
sampled waveform. For this reason, the measurement instructions provide the
best compatibility among different types of instruments. But, as a trade-off, the
compatibility decreases when more flexibility is needed and lower measurement
instruction levels are used.
3.3.1 The MEASure? query
This is the easiest instruction to use and provides the best compatibility. However,
it does not offer access to the full capability of the CombiScope instrument. The
MEASure? query configures the instrument for optimal settings, starts the data
acquisition, and returns the result in one operation. The signal characteristics that
can be acquired in this way are shown in figure 3.2.
Example:
MEASure:AC?
This query measures the RMS voltage of the AC component at the default
input channel 1. After the acquisition, the result is sent to the controller. The
instrument itself selects an optimal setting for this purpose and carries out the
requested measurement as "well" as possible. Moreover, it automatically
starts the measurement.