Fluke PM3370B user manual Time base = 50 * Xr * Xu/div

6 - 40		THE CPL PROTOCOL
Time base	In case of a sampled signal the horizontal scale is called the time
	base. The time base setting is usually expressed in
	seconds/division. Without magnification or compression the
	oscilloscope always displays 50 samples per horizontal division.
	Note:	The horizontal scale as well as the FFT scale can differ. In
		that case it is expressed in X-units per division.
	Time base = 50 * Xr * Xu/div
Delay	Delay is the time delay between the trigger moment and the
	moment that the first sample is taken. If the delay is negative, the
	first sample is taken before the trigger moment. This is called pre-
	trigger view. In case of pre-trigger view the trigger point (horizontal
	position of which T[n]=0) is indicated on the screen. The delay or
	the position of the trigger point can be adjusted by means of the
	TRIGGER POSITION control.
	Delay is usually expressed in X-units (seconds).
	Note:	Traces can also be positioned in horizontal direction with
		the X- POS control, but this does not affect the delay. The

reason is that X-POS is a pure display function and therefore does not affect the signal sampling.

Delay = -(Xz + (dT-corr * Xr)) * Xu

Trigger pos = (Xz + (dT-corr * Xr)) * Xu

These values can also be expressed in divisions :

Delay = ( -(Xz + (dT-corr * Xr)) / Xr ) * 1/50 * div

Trigger pos = ( (Xz +(dT-corr * Xr)) / Xr ) * 1/50 * div

Notes:

•

•

•

The mathematic functions only give useful results, if there is no conflict between the units. For example, it makes no sense to add amperes to volts.

The trigger delay and the time base setting of the two traces must be equal. This is always guaranteed, if the traces were acquired at the same time, because the trace elements are from the same register.

Consider the following useful example of a mathematics function:

-Perform the multiplication of two traces with different units, i.e. a trace representing volts over time and a trace with amperes over time.

-The resulting trace is expressed in watts and gives the power over time.

-After integration this gives the Pulse Power in joules.