---
name: "comedi_set_filter"
section: "3"
platform: "linux"
package: "libcomedi-dev"
version: "0.11.0+5-1.3+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/comedi_set_filter"
---

# comedi\_set\_filter(3)

select a filter for a subdevice

## NAME

comedi\_set\_filter - select a filter for a subdevice

## SYNOPSIS

```
#include <comedilib.h>
```

**int comedi\_set\_filter(comedi\_t \*** *device***, unsigned int** *subdevice***, unsigned int** *channel***, unsigned int** *filter***);**

## STATUS

alpha

## DESCRIPTION

This function selects a filter for a subdevice. For instance, a digital input subdevice may provide deglitching filters with varying cutoff frequencies. The filters are used to prevent high-frequency noise from causing unwanted transitions on the digital inputs. This function can tell the hardware which deglitching filter to use, or to use none at all.

The *filter* parameter selects which of the subdevice's filters to use, and is driver-dependant.

This function is only useable on subdevices that provide support for the **INSN\_CONFIG\_FILTER** configuration instruction.

## RETURN VALUE

0 on success, -1 on error.

## AUTHORS

**David Schleef** \<ds@schleef.org\>

Author.

**Frank Mori Hess** \<fmhess@users.sourceforge.net\>

Author.

**Herman Bruyninckx** \<Herman.Bruyninckx@mech.kuleuven.ac.be\>

Author.

**Bernd Porr** \<tech@linux-usb-daq.co.uk\>

Author.

**Ian Abbott** \<abbotti@mev.co.uk\>

Author.

**Éric Piel** \<piel@delmic.com\>

Author.

## COPYRIGHT

Copyright © 1998-2003 David Schleef\
 Copyright © 2001-2003, 2005, 2008 Frank Mori Hess\
 Copyright © 2002-2003 Herman Bruyninckx\
 Copyright © 2012 Bernd Porr\
 Copyright © 2012 Ian Abbott\
 Copyright © 2012, 2015 Éric Piel\

This document is part of Comedilib. In the context of this document, the term "source code" as defined by the license is interpreted as the XML source.

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, version 2.1 of the License.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.