Fluke PM-3370B, PM-3380B Mathematical calculations, Differentiating and integrating traces

3 - 48 USING THE COMBISCOPE INSTRUMENTS

3.9.2Mathematical calculations

Mathematical calculations can be performed on 2 traces using the CALCulate1:MATH and CALCulate2:MATH functions. These functions comply with the front panel features MATH1 and MATH2 respectively. The calculation can be an addition (+), a subtraction (-), or a multiplication (*). The attenuation of the resulting trace is automatically set higher than the sum of the attenuations of the individual traces.

PROGRAM EXAMPLE:

CALL	Send(0,	8,	"CALCulate:MATH (CH1+CH2)", 1)	’Channel 1 + channel 2
CALL	Send(0,	8,	"CALCulate:MATH:STATe ON", 1)	’Math function enabled

’The resulting trace (CH1 + CH2) is stored in M1_1.

CALL Send(0, 8, "CALCulate2:MATH (M1_1 - CH2)", 1) ’M1_1 - channel 2

’The resulting trace (which is the CH1 trace) is stored in M2_1.

The first argument in the expression that defines the mathematical operation to be performed, is a trace that may be specified either implicitly, or explicitly by its trace name. A trace is specified implicitly when the keyword IMPLied is used as argument in the expression. When IMPlied is specified, the trace that is programmed with the CALCulate:FEED command is used as the first argument in the expression. The trace that determines the second argument must always be specified explicitly by its trace name.

PROGRAM EXAMPLE:

CALL Send(0, 8, "CALCulate:FEED ’CH3’", 1)				’Channel 3	= input source
CALL Send(0,	8,	"CALCulate:MATH (IMPLied+CH2)", 1)’Channel 3			+ channel 2
CALL Send(0,	8,	"CALCulate:MATH:STATe ON",	1)	’Math function enabled

’The resulting trace (CH3 + CH2) is stored in M1_1.

3.9.3Differentiating and integrating traces

The INTegral function performs a point-to-point integration on a trace. The result of the integration process is a trace. Each point in the trace is the integral up to the corresponding point in the original (input) trace.

The DERivative (DIFFerential) function calculates the differential quotient of the trace points. Each point in the resulting trace is the derivative of the corresponding point in the original (input) trace. The width of the differential window can be programmed from 3 to 129 points in increments of 2 points by the CALCulate:DERivative:POINts command. After a *RST command, the number of points is 5.