# :FUNCtion:PARameters:DEMBed:SPAN

DeEmbed (2 port) Parameters Commands

- :FUNCtion:PARameters:DEMBed:ALIGn
- :FUNCtion:PARameters:DEMBed:BANDwidth
- :FUNCtion:PARameters:DEMBed:BLIMit
- :FUNCtion:PARameters:DEMBed:BSPan?
- :FUNCtion:PARameters:DEMBed:CFRequency
- :FUNCtion:PARameters:DEMBed:FNAMe
- :FUNCtion:PARameters:DEMBed:IMPulse
- :FUNCtion:PARameters:DEMBed:MEASsim
- :FUNCtion:PARameters:DEMBed:NGAin
- :FUNCtion:PARameters:DEMBed:RCORr
- :FUNCtion:PARameters:DEMBed:RESolution
- :FUNCtion:PARameters:DEMBed:SPAN
- :FUNCtion:PARameters:DEMBed:STEP

## Command Syntax

    :FUNCtionN:PARameters:DEMBed:SPAN <max_time_span>

<max_time_span> is a double.

Where N identifies one of up to 64 possible operators {1:64} that can be defined as part of a math function. The operators are numbered in the order that they were originally added to the function.

## Query Syntax

    :FUNCtionN:PARameters:DEMBed:SPAN?

## Description

Specifies the filter size of a 2-Port DeEmbedding operator (`:FUNCtion:FOPerator`) by specifying its maximum time span (in seconds).

The correction transfer function is applied by means of a FIR digital filter. The size of this filter determines the time span of the transformation it can apply. However, there is a trade-off. Using a longer filter corrects longer time constants, but it can take longer to calculate. By default, Infiniium tries to choose a filter size that preserves the coarsest frequency resolution used by all of the model blocks. However, you can limit the filter size by reducing the span value.

Increasing the span value increases the maximum time span of the correction transfer function's impulse response. Increasing this control enables Infiniium to apply transformations that have slower time constants. You can use either the Step Response or Impulse Response plot to see if the time span is long enough to model your device adequately.

The maximum time span control is the reciprocal of the minimum frequency resolution control (`:FUNCtion:PARameters:DEMBed:RESolution`), and these controls are tied together, so as you set one to a lower value, the other one raises to a higher value and vice versa.

Generally, you want to set the maximum time span using the Step Response or Impulse Response plot and allow the minimum frequency resolution to be set automatically.