151 lines
5.9 KiB
Groff
151 lines
5.9 KiB
Groff
.\"
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.\" Copyright (c) 1995 HD Associates, Inc.
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by Christopher G. Demetriou.
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.\" 3. The name of the author may not be used to endorse or promote products
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.\" derived from this software withough specific prior written permission
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.\" $Id: labpc.4,v 1.6 1998/10/22 14:51:19 bde Exp $
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.\"
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.rm ES
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.rm EE
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.de ES
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.Pp
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.nf
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.in +0.5i
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..
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.de EE
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.in -0.5i
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.fi
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..
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.Dd April 26, 1995
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.Dt LABPC 4 i386
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.Os FreeBSD
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.Sh NAME
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.Nm labpc
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.Nd
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National Instruments LABPC and LABPC+ driver
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.Sh SYNOPSIS
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.Cd "device labpc0 at isa? port 260 irq 5"
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.Sh DESCRIPTION
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This supports the National Instruments LABPC and LABPC+ \fILow-Cost
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Multifunction I/O Board\fP.
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.Pp
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This board provides 8 12 bit A-D input channels, 2 12 bit D-A output
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channels, and 3 8 bit digital I/O ports. It also supports setting
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up the National Instruments SCXI bus off the digital I/O ports,
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although that software is currently present in an external program
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and not as part of the driver.
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.Pp
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The selection of the input or output device, mode, and channel is
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through the minor number:
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.ES
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The 8 bit minor number format is UUSIDCCC, with
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UU: Board unit.
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S: SCAN bit for scan enable.
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I: INTERVAL for interval support
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D: 1: Digital I/O, 0: Analog I/O
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CCC: The channel selector:
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ANALOG:
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input: channel must be 0 to 7 for AD0 ... AD7
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output: channel must be 0 to 2
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0: D-A 0
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1: D-A 1
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2: Alternate channel 0 then 1
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DIGITAL:
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input: Channel must be 0 to 2.
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output: Channel must be 0 to 2.
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.EE
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.Pp
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The /dev/MAKEDEV script will make the basic analog and digital
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devices if you do "sh MAKEDEV labpcaio" and "sh MAKEDEV labpcdio",
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however, it won't make device entries for INTERVAL and SCAN devices.
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SCAN devices automatically scan over all channels from the channel
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number down to 0 (for example, a SCAN for /dev/ad7 will read channels
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AD7 ... AD0) while the INTERVAL device will wait for an external
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signal and then read all the channels from the selected channel
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number down to 0 as fast as it can. This is done by the hardware
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and not the driver (other than turning it on); See the \fILabPC+
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User's Manual\fP and the source code if this doesn't make sense to
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you.
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.Pp
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The driver supports several general analog I/O ioctl calls. These
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are defined in sys/dataacq.h and are intended to be implemented in
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other data acquisition board device drivers.
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.Pp
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AD_MICRO_PERIOD_SET takes a pointer to a long argument specifying
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the number of microseconds between samples.
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.Pp
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AD_MICRO_PERIOD_GET takes a pointer to a long argument and returns
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the current number of microseconds between samples.
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.Pp
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AD_NGAINS_GET takes a pointer to an integer and returns the number
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of different gain settings the board supports. This is 8 for the
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LabPC board.
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.Pp
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AD_NCHANS_GET takes a pointer to an integer and returns the number
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of channels the board supports. This is 8 for the LabPC board.
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.Pp
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AD_SUPPORTED_GAINS returns an array of NGAINS (the number obtained
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by AD_NGAINS_GET) doubles. These are the gains the board supports.
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.Pp
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AD_GAINS_SET takes an array of NCHANS (the number obtained by
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AD_NCHANS_GET) integers and sets the board gains. These are indices
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into the supported gain array, with one gain for each channel.
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.Pp
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AD_GAINS_GET takes an array of NCHANS (returned by AD_NCHANS_GET)
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integers and returns the current board gains.
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.Sh BUGS
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In general, only those capabilities that I needed are present. In
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particular the following notable restrictions are present.
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.Pp
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The analog input is only supported in a clocked conversion mode.
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.Pp
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You can only set the sample clock down to 15 Hz. Anything slower
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needs a modification to the driver to support TCINTEN in order to
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chain together the counters to get a lower clock rate.
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.Pp
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There is no support for clocked D-A output.
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.Pp
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The 8255 providing the digital I/O ports is supported only in mode
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0 (three 8 bit ports).
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.Pp
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There is support for the SCXI bus off the LABPC board. It is not
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in the driver but is a separate user process that accesses the
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digital I/O devices. Ask dufault@hda.com for it.
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.Pp
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MAKEDEV only makes the "basic" devices. You must make the INTERVAL
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or SCAN devices by hand.
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.Pp
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The INTERVAL device sets the clock rate as high as possible so that
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it samples all the channels as quickly as it can after the external
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signal. This is a silly restriction; it should simply use the
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clock setting.
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.Sh CAVEATS
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National Instrument's (like most other laboratory grade board
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vendors) definition of Low-Cost differs dramatically from many on
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the net.
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