This section assumes that you have successfully compiled and installed
the &comedi; software, that your hardware device is in your computer,
and that you know the relevant details about it, i.e., what kind of
- card it is, the I/O base, the IRQ, jumper settings related to input
- ranges, etc.
+ card it is, any jumper settings related to input ranges, the
+ I/O base address and IRQ for old non-plug-n-play boards, etc.
</para>
-
<section id="cardconfiguration">
<title>
Configuration
to tell the &comedi; core kernel module which device you have, which
driver you want to attach to the card, and which run-time options
you want to give to the driver. This configuration is done by running
- the <command>comedi_config</command> command. (As root of course.)
+ the <command>comedi_config</command> command (as root).
Here is an example of how to use the command (perhaps you should read
its <command>man</command> page now):
<screen>
-PATH=/sbin:/usr/sbin:/usr/local/sbin:$PATH
comedi_config /dev/comedi0 labpc-1200 0x260,3
</screen>
This command says that the <quote>file</quote>
<filename>/dev/comedi0</filename> can be used to access the &comedi;
device that uses the <parameter>labpc-1200</parameter> board, and that
you give it two run-time parameters (<literal>0x260</literal> and
- <literal>3</literal>). More parameters are possible, for example to
- discriminate between two or more identical cards in your system.
- </para>
- <para>
- If you want to have the board configured in this way every time you
- boot, put the lines above into a start-up script file of your Linux
- system (for example, the
- <filename>/etc/rc.d/rc.local</filename> file), or for PCMCIA
- boards the appropriate place is the /etc/pcmcia/comedi script.
- For non-PCMCIA boards, you can also arrange to have your driver
- loaded and comedi_config run with by adding a few lines
- to /etc/modules.conf (see the INSTALL file for the comedi
- kernel modules). You can, of course, also run comedi_config
- at a command prompt.
+ <literal>3</literal>). More parameters are possible, and their
+ meaning is driver dependant.
</para>
<para>
<screen>
comedi_config /dev/comedi0 ni_atmio
</screen>
- </para>
- <para>
- For the <literal>Data Translation</literal> board, you need to have a
- list of the jumper settings; these are given in the &comedi; manual
- section about this card. (Check first to see whether they are still
- correct!)
- The card discussed her is a <literal>DT2821-f-8di</literal>. The
- <command>man</command> page of <command>comedi_config</command> tells
- you that you need to know the I/O base, IRQ, DMA 1, DMA 2. However,
- the &comedi; driver also recognizes the
- differential/single-ended and unipolar/bipolar jumpers. As always,
- the source is the final authority, and looking in
- <filename>module/dt282x.c</filename>
- tells us that the options list is interpreted as:
- </para>
- <para>
- (... TO BE FILLED IN ...)
- </para>
-
- <!-- XXX
- <itemize>
- <item>I/O base
- <item>IRQ
- <item>1=differential, 0=single ended
- <item>ai 0=unipolar, 1=bipolar
- <item>ao0 0=unipolar, 1=bipolar
- <item>ao1 0=unipolar, 1=bipolar
- <item>dma1
- <item>dma2
- </itemize>
- (ai=analog input, ao=analog output.)
- -->
-
- <para>
- So, the appropriate options list is:
+ For the preceding comedi_config command to succeed, the
+ ni_atmio kernel module must
+ be loaded first. For plug-n-play boards on
+ modern kernels, the appropriate comedi kernel modules should get loaded
+ automatically when your computer is booted.
+ The <command>modprobe</command> command can
+ be used to manually load/unload kernel modules, and <command>lsmod</command>
+ will list all the currently loaded modules.
+ </para>
+ <para>
+ For the <literal>Data Translation</literal> board, you need to know
+ how the board's jumpers are configured in order to specify the correct
+ comedi_config parameters. These parameters for the board are given in the
+ <link endterm="lowleveldrivers">kernel drivers</link> section about the dt282x
+ driver.
+ The card discussed here is a <literal>DT2821-f-8di</literal>. The
+ entry for the dt282x driver tells you that the
+ comedi_config parameters give the driver the I/O base,
+ IRQ, DMA 1, DMA 2, and
+ in addition the states of the
+ differential/single-ended and unipolar/bipolar jumpers:
+ <itemizedlist>
+ <title>dt282x configuration options:</title>
+ <listitem><para>[0] - I/O port base address</para></listitem>
+ <listitem><para>[1] - IRQ</para></listitem>
+ <listitem><para>[2] - DMA 1</para></listitem>
+ <listitem><para>[3] - DMA 2</para></listitem>
+ <listitem><para>[4] - AI jumpered for 0=single ended, 1=differential</para></listitem>
+ <listitem><para>[5] - AI jumpered for 0=straight binary, 1=2's complement</para></listitem>
+ <listitem><para>[6] - AO 0 jumpered for 0=straight binary, 1=2's complement</para></listitem>
+ <listitem><para>[7] - AO 1 jumpered for 0=straight binary, 1=2's complement</para></listitem>
+ <listitem><para>[8] - AI jumpered for 0=[-10,10]V, 1=[0,10], 2=[-5,5], 3=[0,5]</para></listitem>
+ <listitem><para>[9] - AO 0 jumpered for 0=[-10,10]V, 1=[0,10], 2=[-5,5], 3=[0,5],
+ 4=[-2.5,2.5]</para></listitem>
+ <listitem><para>[10]- A0 1 jumpered for 0=[-10,10]V, 1=[0,10], 2=[-5,5], 3=[0,5],
+ 4=[-2.5,2.5]</para></listitem>
+ </itemizedlist>
+ </para>
+
+ <para>
+ So, the appropriate options list might be:
<screen>
-0x200,4,,1,1,1
+0x200,4,0,0,1,1,1,1,0,2,2
</screen>
and the full configuration command is:
<screen>
-comedi_config /dev/comedi1 dt2821-f-8di 0x200,4,,1,1,1
+comedi_config /dev/comedi1 dt2821-f-8di 0x200,4,0,0,1,1,1,1,0,2,2
</screen>
- The differential/single-ended number is left blank, since the
- driver already knowns (from the board name), that it is
- differential. Also the DMA numbers are left blank, since we
- don't want the driver to use DMA. (Which could interfere
- with the sound card...)
+ Setting the DMA channels to 0 disables the use of DMA.
</para>
<para>
So now you have your boards configured correctly.
Since data acquisition boards are not typically well-engineered,
- &comedi; sometimes can't figure out if the board is actually there.
+ &comedi; sometimes can't figure out if an old non-plug-n-play
+ board is actually in the computer and at the base address you specified.
If it can't, it assumes you are right. Both of these boards
are well-made, so &comedi; will give an error message if it
can't find them. The &comedi; kernel module, since it is a part
<para>
So now that you have &comedi; talking to the hardware, try to
- talk to &comedi;. Here's some pretty low-level information, which can
- sometimes be useful for debugging:
+ talk to &comedi;. Here's some information from comedi's proc
+ file, which indicates what drivers are loaded and which
+ boards are configured:
</para>
<screen>
</screen>
<para>
- On the particular system this demonstration was carried out, this
- command gives:
+ For example, on a computer with an NI pxi-6281 configured on
+ <filename>/dev/comedi0</filename> and
+ a pxi-6602 configured on <filename>/dev/comedi1</filename> you might
+ see something like:
</para>
<screen>
-comedi version 0.6.4
-format string
-0: ni_atmio at-mio-16e-10 7
-1: dt282x dt2821-f-8di 4
+comedi version 0.7.74
+format string: "%2d: %-20s %-20s %4d",i,driver_name,board_name,n_subdevices
+ 0: ni_pcimio pxi-6281 14
+ 1: ni_660x PXI-6602 10
+ni_pcimio:
+ ni_pcimio
+8255:
+ 8255
+ni_660x:
+ ni_660x
</screen>
<para>
This documentation feature is not well-developed yet. Basically, it
currently returns the driver name, the device name, and the number of
- subdevices.
+ subdevices. Following those lines are a list of the comedi kernel
+ driver modules currently loaded, each followed by a list of the board
+ names it recognizes (names that can be used with comedi_config).
</para>
<para>
- In the <filename role="directory">demo/</filename> directory, there is a
+ In the <filename role="directory">demo/</filename> subdirectory of
+ Comedilib, there is a
command called <command>info</command>, which provides information
about each subdevice on the board. Its output can be rather long,
if the board has several subdevices.
Here's part of the output of the <literal>National Instruments</literal>
board (which is on <filename>/dev/comedi0</filename>), as a result of
- the command <command>demo/info /dev/comedi0</command>:
+ the command <command>demo/info /dev/comedi0</command> (run from the
+ top-level directory of comedilib):
</para>
<screen>
projects / comedilib.git / commitdiff