---
name: "comedi_data_read_hint"
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_data_read_hint"
---

# comedi\_data\_read\_hint(3)

tell driver which channel/range/aref you are going to read from next

## NAME

comedi\_data\_read\_hint - tell driver which channel/range/aref you are going to read from next

## SYNOPSIS

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

**int comedi\_data\_read\_hint(comedi\_t \*** *device***, unsigned int** *subdevice***, unsigned int** *channel***, unsigned int** *range***, unsigned int** *aref***);**

## DESCRIPTION

Used to prepare an analog input for a subsequent call to **comedi\_data\_read**. It is not necessary to use this function, but it can be useful for eliminating inaccuracies caused by insufficient settling times when switching the channel or gain on an analog input. This function sets an analog input to the channel, range, and aref specified but does not perform an actual analog to digital conversion.

Alternatively, one can simply use **comedi\_data\_read\_delayed**, which sets up the input, pauses to allow settling, then performs a conversion.

## 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.