e.g. FftOrderAnalysisAmpl('Expression','Time','Freq','MinOrder'=0,'MaxOrder','Order subdivision'=1,'Window'=0,'Overlap'=0,'SuppressDC'=FALSE)

Arguments

'Expression'	Signal or expression for which to carry out the order analysis
'Time'	Determination of the time or length intervals used
'Freq'	Basic frequency for the order analysis (rotational frequency)
'MinOrder'	Minimum displayed order
'MaxOrder'	Maximum displayed order
'Order subdivision'	Grid width between the integer orders
'Window'	Window type: 0 = Square 1 = Bartlett 2 = Blackman 3 = Hamming 4 = Hanning 5 = Blackman-Harris 6 = Flat top
'Overlap'	Overlap factor
'SuppressDC'	DC suppression

Description

This function calculates the orders (i.e. multiples of a basic frequency 'Freq') for a signal and returns a vector with the orders between 'MinOrder' and 'MaxOrder'. The number of data points per order is determined by the parameter 'Order subdivision'.

You can use the 'Window' parameter to set the window type that is used for the calculation. The overlap factor determines the overlapping of the time segments and can be between 0 (no overlap) and 1 (complete overlap). Optionally, you can activate DC suppression with the 'SuppressDC' parameter.

Contrary to the FftInTime function, the time/frequency is no longer displayed on the Y-axis, but the rotational frequency and its multiple, i.e. the orders. The frequency axis is distorted in accordance with the current revolutions per minute so that the orders are no longer displayed as a curve, but as straight lines. Depending on the function, either an amplitude trend (FftOrderAnalysisAmpl) or a power trend (FftOrderAnalysisPower) is calculated.

Note
	The function does not yield results if the number of signal points per revolution is more than twice as high as the selected parameter 'Time'.

Example

With the FftOrderAnalysis function, you can calculate an order analysis. Frequencies corresponding to the motor speed or its multiple are called orders. The first order complies with the frequency of the motor speed, the second order complies with the frequency of the first order multiplied by the factor 2, etc. The order analysis calculates the level or the level curve of this order.

An interpolation is carried out between the individual signal points to calculate the FftOrderAnalysis.