'\" t
.\"     Title: comedi_dio_bitfield2
.\"    Author: David Schleef <ds@schleef.org>
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 02/28/2024
.\"    Manual: Comedi reference
.\"    Source: Comedi
.\"  Language: English
.\"
.TH "COMEDI_DIO_BITFIELD2" "3" "02/28/2024" "Comedi" "Comedi reference"
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.SH "NAME"
comedi_dio_bitfield2 \- read/write multiple digital channels
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <comedilib\&.h>
.fi
.ft
.HP \w'int\ comedi_dio_bitfield2('u
.BI "int comedi_dio_bitfield2(comedi_t\ *\ " "device" ", unsigned\ int\ " "subdevice" ", unsigned\ int\ " "write_mask" ", unsigned\ int\ *\ " "bits" ", unsigned\ int\ " "base_channel" ");"
.SH "DESCRIPTION"
.PP
The function
\fBcomedi_dio_bitfield2\fR
allows multiple channels to be read or written together on a digital input, output, or configurable digital I/O device\&. The parameter
\fIwrite_mask\fR
and the value pointed to by
\fIbits\fR
are interpreted as bit fields, with the least significant bit representing channel
\fIbase_channel\fR\&. For each bit in
\fIwrite_mask\fR
that is set to 1, the corresponding bit in
*\fIbits\fR
is written to the digital output channel\&. After writing all the output channels, each channel is read, and the result placed in the approprate bits in
*\fIbits\fR\&. The result of reading an output channel is the last value written to the output channel\&.
.PP
All the channels might not be read or written at the exact same time\&. For example, the driver may need to sequentially write to several registers in order to set all the digital channels specified by the
\fIwrite_mask\fR
and
\fIbase_channel\fR
parameters\&.
.SH "RETURN VALUE"
.PP
If successful,
0
is returned, otherwise
\-1\&.
.PP
.SH "AUTHORS"
.PP
\fBDavid Schleef\fR <\&ds@schleef.org\&>
.RS 4
Author.
.RE
.PP
\fBFrank Mori Hess\fR <\&fmhess@users.sourceforge.net\&>
.RS 4
Author.
.RE
.PP
\fBHerman Bruyninckx\fR <\&Herman.Bruyninckx@mech.kuleuven.ac.be\&>
.RS 4
Author.
.RE
.PP
\fBBernd Porr\fR <\&tech@linux-usb-daq.co.uk\&>
.RS 4
Author.
.RE
.PP
\fBIan Abbott\fR <\&abbotti@mev.co.uk\&>
.RS 4
Author.
.RE
.PP
\fB\('Eric Piel\fR <\&piel@delmic.com\&>
.RS 4
Author.
.RE
.SH "COPYRIGHT"
.br
Copyright \(co 1998-2003 David Schleef
.br
Copyright \(co 2001-2003, 2005, 2008 Frank Mori Hess
.br
Copyright \(co 2002-2003 Herman Bruyninckx
.br
Copyright \(co 2012 Bernd Porr
.br
Copyright \(co 2012 Ian Abbott
.br
Copyright \(co 2012, 2015 \('Eric Piel
.br
.PP
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.
.PP
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.
.PP
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.
.PP
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.
.sp