Fluke PM-3370B, PM-3380B, PM-3390B, PM-3394B, PM-3384B user manual MEASure? query, MEASureAC?

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.

3.3.1The 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.