# :CHANnel:FILTer:TYPE

:CHANnel FILTer Commands

- :CHANnel FILTer Commands
- :CHANnel:FILTer:ACQuisition:BANDwidth
- :CHANnel:FILTer:ACQuisition:MODE
- :CHANnel:FILTer:BANDwidth
- :CHANnel:FILTer:CFRequency
- :CHANnel:FILTer:SPAN?
- :CHANnel:FILTer:TYPE

## Command Syntax

    :CHANnelN:FILTer:TYPE {OFF | BESSel | BUTTerworth | BANDpass | BRICkwall}

Where N identifies a specific channel in the form "<connection1-8>_<ch1-8>". With connection 1, the connection number part (that is, "1_") is optional, and you can simply use the channel number "<ch1-8>". For example, connection 4 channel 2 is `CHANnel4_2`.

## Query Syntax

    :CHANnelN:FILTer:TYPE?

## Description

This command lets you select the response of the individual channel bandwidth limit filter.

OFF
  In this case, no bandwidth limiting filter is applied, and the channel has the full bandwidth provided by the oscilloscope hardware.
BESSel
  Specifies a 4th order Bessel response for the bandwidth limit filter. This response has a more gradual roll-off.

  To achieve the 4th order Bessel response, the maximum bandwidth you can specify is about 2/3 of the maximum bandwidth you could specify with the Brick-Wall filter. Also with the Bessel filter, the brick-wall response takes over at what would be the brick-wall filter's maximum bandwidth. Therefore, you can have a combination of roll-off responses with this selection.

BUTTerworth
  Specifies a 4th order Butterworth response for the bandwidth limit filter. This response has a roll-off that is between the Brick Wall and Bessel responses.

  To achieve the 4th order Butterworth response, the maximum bandwidth you can specify is about 80% of the maximum bandwidth you could specify with the Brick-Wall filter. Also with the Butterworth filter, the brick-wall response takes over at what would be the brick-wall filter's maximum bandwidth. Therefore, you can have a combination of roll-off responses with this selection.

BANDpass
  This option is used with the Phase Noise analysis application. Because you do not have control over the slope of the transition from the pass band to the rejected bands, this option has limited usefulness as a general-purpose bandpass filter.
BRICkwall
  Specifies a Brick-Wall response for the bandwidth limit filter. This response has a sharp roll-off.