Agilent Technologies 5000 Series manual Peak Data

Commands by Subsystem 3

This data is transmitted over the interface linearly, starting with time bucket 0 and proceeding through time bucket n- 1, where n is the number returned by the :WAVeform:POINts? query (see page 413). The first value corresponds to a point at the left side of the screen and the last value corresponds to one point away from the right side of the screen. The maximum number of points that can be returned in average mode is 1000 unless ACQuire:COUNt has been set to 1.

PEAK Data

Peak detect display mode is used to detect glitches for time base settings of 500 us/div and slower. In this mode, the oscilloscope can sample more data than it can store and display. So, when peak detect is turned on, the oscilloscope scans through the extra data, picks up the minimum and maximum for each time bucket, then stores the data in an array. Each time bucket contains two data sample.

The array is transmitted over the interface bus linearly, starting with time bucket 0 proceeding through time bucket n- 1, where n is the number returned by the :WAVeform:POINts? query (see page 413). In each time bucket, two values are transmitted, first the minimum, followed by the maximum. The first pair of values corresponds to the time bucket at the leftmost side of the screen. The last pair of values corresponds to the time bucket at the far right side of the screen. In :ACQuire:TYPE PEAK mode (see page 132), the value returned by the :WAVeform:XINCrement query (see page 428) should be doubled to find the time difference between the min- max pairs.

HRESolution Data

The high resolution (smoothing) mode is used to reduce noise at slower sweep speeds where the digitizer samples faster than needed to fill memory for the displayed time range. This mode is the same as the AVERage mode with :ACQuire:COUNt 1.

Data Conversion

Word or byte data sent from the oscilloscope must be scaled for useful interpretation. The values used to interpret the data are the X and Y references, X and Y origins, and X and Y increments. These values are read from the waveform preamble. Each channel has its own waveform preamble.

In converting a data value to a voltage value, the following formula is used:

voltage = [(data value - yreference) * yincrement] + yorigin

If the :WAVeform:FORMat data format is ASCii (see page 412), the data values are converted internally and sent as floating point values separated by commas.

Agilent InfiniiVision 5000 Series Oscilloscopes Programmer's Reference 405