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Extracts the modulating signal, or envelope signal, from an amplitude-modulated signal. You can use the envelope detection technique to identify the mechanical faults that have amplitude-modulating effect on the vibration signal of a machine.

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Examples

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Select an instance OAT Envelope Detection (Waveform Output, 1 Channel)OAT Envelope Detection (Waveform Output, N Channels)OAT Envelope Detection (Even Angle Output, 1 Channel)OAT Envelope Detection (Even Angle Output, N Channels)

OAT Envelope Detection (Waveform Output, 1 Channel)

	reset? specifies the initialization of the internal states. If reset? is TRUE, or when the VI first runs, the internal states initialize to zero. If reset? is FALSE, this VI sets the internal states to the final states from the previous call to the VI. The default is FALSE.
	scaled signal [EU] specifies the scaled signal expressed in the selected engineering units. To obtain a properly scaled signal, you can use the SVL Scale Voltage to EU VI or define a virtual channel in Measurement & Automation Explorer (MAX).
	band specification specifies the frequency band to use to calculate the envelope signal of the scaled signal [EU]. center frequency [Hz] specifies the center frequency of the frequency band to use to calculate the envelope signal. The default is 4800. span [Hz] specifies the frequency bandwidth to calculate the envelope signal. The span [Hz] value only defines half of the frequency band, which is from the center frequency [Hz] to the frequency band upper limit. The default is 2000.
	error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node. status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE. code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
	envelope signal [EU] returns the envelope signal of the scaled signal [EU].
	error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error. status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

OAT Envelope Detection (Waveform Output, N Channels)

	reset? specifies the initialization of the internal states. If reset? is TRUE, or when the VI first runs, the internal states initialize to zero. If reset? is FALSE, this VI sets the internal states to the final states from the previous call to the VI. The default is FALSE.
	scaled signals [EU] specifies the scaled signals expressed in the selected engineering units. To obtain a properly scaled signal, you can use the SVL Scale Voltage to EU VI or define a virtual channel in Measurement & Automation Explorer (MAX).
	band specification specifies the frequency band to use to calculate the envelope signals of the scaled signals [EU]. center frequency [Hz] specifies the center frequency of the frequency band to use to calculate the envelope signal. The default is 4800. span [Hz] specifies the frequency bandwidth to calculate the envelope signal. The span [Hz] value only defines half of the frequency band, which is from the center frequency [Hz] to the frequency band upper limit. The default is 2000.
	error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node. status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE. code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
	envelope signals [EU] returns the envelope signals of the scaled signals [EU].
	error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error. status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

OAT Envelope Detection (Even Angle Output, 1 Channel)

	reset? specifies the initialization of the internal states. If reset? is TRUE, or when the VI first runs, the internal states initialize to zero. If reset? is FALSE, this VI sets the internal states to the final states from the previous call to the VI. The default is FALSE.
	scaled signal [EU] specifies the scaled signal expressed in the selected engineering units. To obtain a properly scaled signal, you can use the SVL Scale Voltage to EU VI or define a virtual channel in Measurement & Automation Explorer (MAX).
	speed profile specifies the arrival time and the rotational speed of each tachometer pulse. time [s] specifies the arrival time, in seconds, of each tachometer pulse. speed [RPM] specifies the rotational speed, in revolutions per minute, of each tachometer pulse.
	pulse/revolution specifies the number of pulses the tachometer generates during each revolution. The default is 1.
	band specification specifies the order band to use to calculate the envelope signal of the scaled signal [EU]. center specifies the center frequency or the center order of the order band to use to calculate the envelope signal. Use center frequency for a variable-speed bearing fault detection. value specifies the value of the center frequency or center order to use to calculate the envelope signal. The default is 0. unit specifies the unit of the center input. When unit is Hz, value specifies the value of the center frequency. When unit is order, value specifies the value of the center order. 0 Hz (Default) 1 order span [order] specifies the order bandwidth to calculate the envelope signal. span [order] value only defines half of the order band, which is from the center to the order band upper limit. The default is 0.
	error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node. status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE. code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
	even-angle envelope signal returns the even-angle envelope signal of the scaled signal [EU]. even-angle envelope signal is synchronous to the rotational speed with constant number of samples per revolution. r0 returns the starting index value for counting revolutions. dr returns the revolution interval between two sequential samples. Y returns the value of the even-angle-spaced sample in scaled engineering unit.
	even-angle channel info returns information about the measurement configuration for the even-angle envelope signal.
	error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error. status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.
	actual max order returns the actual maximum order this VI uses.

OAT Envelope Detection (Even Angle Output, N Channels)

	reset? specifies the initialization of the internal states. If reset? is TRUE, or when the VI first runs, the internal states initialize to zero. If reset? is FALSE, this VI sets the internal states to the final states from the previous call to the VI. The default is FALSE.
	scaled signals [EU] specifies the scaled signals expressed in the selected engineering units. To obtain a properly scaled signal, you can use the SVL Scale Voltage to EU VI or define a virtual channel in Measurement & Automation Explorer (MAX).
	speed profile specifies the arrival time and the rotational speed of each tachometer pulse. time [s] specifies the arrival time, in seconds, of each tachometer pulse. speed [RPM] specifies the rotational speed, in revolutions per minute, of each tachometer pulse.
	pulse/revolution specifies the number of pulses the tachometer generates during each revolution. The default is 1.
	band specification specifies the order band to use to calculate the envelope signals of the scaled signals [EU]. center specifies the center frequency or the center order of the order band to use to calculate the envelope signals of the scaled signals [EU]. Use center frequency for a variable-speed bearing fault detection. value specifies the value of the center frequency or center order to use to calculate the envelope signal. The default is 0. unit specifies the unit of the center input. When unit is Hz, value specifies the value of the center frequency. When unit is order, value specifies the value of the center order. 0 Hz (Default) 1 order span [order] specifies the order bandwidth to calculate the envelope signal. span [order] value only defines half of the order band, which is from the center to the order band upper limit. The default is 0.
	error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node. status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE. code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
	even-angle envelope signals returns the even-angle envelope signals of the scaled signals [EU]. even-angle envelope signals is synchronous to the rotational speed with constant number of samples per revolution. r0 returns the starting index value for counting revolutions. dr returns the revolution interval between two sequential samples. Y returns the value of the even-angle-spaced sample in scaled engineering unit.
	even-angle channel info returns information about the measurement configuration for the even-angle envelope signals.
	error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error. status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.
	actual max order returns the actual maximum order this VI uses.

Examples

Refer to the following VIs for examples of using the OAT Envelope Detection VI:

• Envelope Detection Constant Speed (Offline) VI: labview\examples\Order Analysis\Fault Analysis
• Envelope Detection Variable Speed (Offline) VI: labview\examples\Order Analysis\Fault Analysis