Hi,
Stefan Schaal wrote:
> Hi Alexis,
>
> I guess I slowly understand that my clocking signal connected to
> scan_begin_arg has to come from an external DIO input, if
> scan_bigin_src = TRIG_EXT, and that the insn instruction is still
> needed to trigger the entire acquisition.
Yes. The trigger instruction is needed so as to start the whole
acquisition (which is composed of many scans). A periodic external
signal is needed so as to trigger each scan.
>
> Alternatively, would it be possible to use the internal clocking signals
> like
>
> scan_bigin_src = TRIG_FOLLOW
>
> or
>
> scan_bigin_src = TRIG_TIMER
I think you are right. If the sampling clock comes from another
subdevice, TRIG_EXT may not be the most appropriate constant. However,
the original comedi driver only expects TRIG_EXT even if... the
sampling signal is not external.
TRIG_TIMER does not seem suitable because it assumes an independant
sampling clock is available.
And TRIG_FOLLOW may be the most appropriate one. We should modify the
driver so that TRIG_FOLLOW is used if the analog sampling clock is
chosen.
>
>
> if I try any of these sources, I get an error -22, and dmesg reports:
>
> [195882.321300] Analogy: a4l_check_cmddesc: scan_begin_src, trigger
> unsupported
>
For me, the command interface is an empty shell because the various
parameters (start_src, scan_begin_src, ...) and the values (TRIG_*)
are imposed. And, on the other side, the driver is fully in charge of
the command structure as it is. So, the comedi command imposes a
communication method but does not ease the driver's task of managing
it (errors checking, translation, etc.)
And, in our case: DIO, we may conclude that this imposed API does not
fit well: in scan_begin_arg, we have to pass an index which is
supposed to correspond to some sampling clock (which is specific to a
board). Then, we use a generic interface with board-specific
arguments.
So, to sum up, I understand your point: the way we control the driver
may not always be the most appropriate one. But, we inherited from
comedi both the interface and the drivers.
On my side, I am working on trying to implement (as a background task)
a generic interface a little bit more based on discovery (query /
enum) that would render the command interface obsolete. Unfortunately,
I have nothing interesting to show yet.
> Best wishes,
>
> -STefan
>
>
>
>
>
> On Jul 9, 2010, at 17:10, Stefan Schaal wrote:
>
> > Hi Alexis,
> >
> > thanks a lot for the clarification. Thus, scan_begin_arg is set to the
> > digital line that I would like to use as a trigger. The triggering itself
> > has to happen by flipping the bit on this specific digital line, e.g.,
> > using a4l_sync_dio() on this specific line? I assume that I do not need to
> > re-wire anything on my board.
> >
> > In your cmd_bits.c code, you use the "a4l_insn_t insn" structure below for
> > triggering, which is what I have to replace with a4l_sync_dio(), I guess?
> >
> > Best wishes,
> >
> > -Stefan
> >
> >
> >
> > On Jul 9, 2010, at 15:17, Alexis Berlemont wrote:
> >
> >> Stefan Schaal wrote:
> >>> Hi Alexis,
> >>>
> >>> I conceptually understand what you are telling us, but I am bit confused
> >>> how to implement your advice:
> >>>
> >>>> So, Stefan, here is a quick solution:
> >>>>
> >>>> if you have access to your board you can choose one of these signals
> >>>> (in which a regular pulse is occuring) and you can modify accordingly
> >>>> the field scan_begin_arg of the structure a4l_cmd_t in cmd_bits.c.
> >>>
> >>> The data structures in question are:
> >>>
> >>> /* The command to send by default */
> >>> a4l_cmd_t cmd = {
> >>> .idx_subd = -1,
> >>> .flags = 0,
> >>> .start_src = TRIG_INT,
> >>> .start_arg = 0,
> >>> .scan_begin_src = TRIG_EXT,
> >>> .scan_begin_arg = 0, /* in ns */
> >>> .convert_src = TRIG_NOW,
> >>> .convert_arg = 0, /* in ns */
> >>> .scan_end_src = TRIG_COUNT,
> >>> .scan_end_arg = 4,
> >>> .stop_src = TRIG_NONE,
> >>> .stop_arg = 0,
> >>> .nb_chan = 4,
> >>> .chan_descs = chans,
> >>> };
> >>>
> >>> a4l_insn_t insn = {
> >>> .type = A4L_INSN_INTTRIG,
> >>> .idx_subd = -1,
> >>> .data_size = 0,
> >>> };
> >>>
> >>>
> >>> Thus, I assume you mean that
> >>>
> >>> scan_begin_src = TRIG_EXT
> >>>
> >>> should be modified to one of the enum items below? Are all these
> >>> timers automatically running, or do they need to be configured, too?
> >>> Sorry, I am a bit at a loss how to proceed.
> >>
> >> Sorry for the delay.
> >>
> >> I was not clear enough. In fact, scan_begin_arg should be
> >> modified. scan_begin_src indicates the type of trigger and
> >> scan_begin_arg gives an associated argument. In our case, it is the
> >> signal number. Sorry for the comment (/* in ns */) which is an
> >> inappropriate copy-paste (as a matter of fact, it is the whole command
> >> interface which is unsuitable but that's another topic).
> >>
> >>>
> >>> Best wishes,
> >>>
> >>> -Stefan
> >>>
> >>>
> >>> On Jul 5, 2010, at 15:02, Alexis Berlemont wrote:
> >>>
> >>>> Hi,
> >>>>
> >>>> Alexis Berlemont wrote:
> >>>>> Hi,
> >>>>>
> >>>>> Stefan Schaal wrote:
> >>>>>> Hi Alexis,
> >>>>>>
> >>>>>> thanks for the feedback. We have 32 bit DIO on subdevice #2, and I am
> >>>>>> not sure that there is anything special to be configured. I will check
> >>>>>> again. Feel free to log into our machine with the pwd I indicated to
> >>>>>> you some time ago. The computer is not used productively.
> >>>>>>
> >>>>>
> >>>>> Sorry for answering late, I was unavailable.
> >>>>>
> >>>>> My question was: did you ensure that the digital line were properly
> >>>>> modified after having launched cmd_bits ?
> >>>>>
> >>>>> As I said, the digital output system does not consume the data (now I
> >>>>> am sure). I instrumetented the code and I found out that the mite
> >>>>> copied about 8000 bytes from the RAM and filled the digital output
> >>>>> FIFO. Then, the DO FIFO status register keeps on indicating the FIFO
> >>>>> is full. Nothing happens, the digital output system does not retrieve
> >>>>> data from the FIFO.
> >>>>>
> >>>>> I tried to find out why and I had a close look at the driver: I
> >>>>> noticed that no sample clock was configured. The driver only proposes
> >>>>> to use an external signal (from the digital system, so AI/AO clocks,
> >>>>> counters, PFI, etc.) as sample clock. Unfortunately, I do not know
> >>>>> which value corresponds to which clock source.
> >>>>>
> >>>>> I had a look a the DAQ documentation: unfortunately the M series
> >>>>> digital system is different (the DAQ-STC document is not valid for
> >>>>> this board). I tried to find the M series developer manual but it is
> >>>>> unavailable according to the NI support. I found a document named
> >>>>> mseries_registermap.doc in:
> >>>>> http://digital.ni.com/express.nsf/bycode/exyv4w?opendocument
> >>>>>
> >>>>> Unfortunately, it does not tell how to configure the sample clock
> >>>>> source (I know which register I have to fill, but I do not know which
> >>>>> value to put so as to use AI clock, digital counters or PFI...)
> >>>>>
> >>>>> So, I am kind of stuck. I will proceed on looking for the missing
> >>>>> pieces of information. Please, if anyone have the info (the mapping
> >>>>> between the "CDO_Mode register" values and the sample clock source),
> >>>>> do not hesitate to help us.
> >>>>>
> >>>>
> >>>> Argh, I found it. I did not see an item in the url displayed above.
> >>>>
> >>>>
> >>>> Here is an enum found in:
> >>>> ftp://ftp.ni.com/support/daq/mhddk/examples/nimseries.zip
> >>>>
> >>>> // Field Accessors (Compile-time selectable)
> >>>> typedef enum {
> >>>> kCDO_Update_Source_SelectGround = 0,
> >>>> kCDO_Update_Source_SelectPFI0 = 1,
> >>>> kCDO_Update_Source_SelectPFI1 = 2,
> >>>> kCDO_Update_Source_SelectPFI2 = 3,
> >>>> kCDO_Update_Source_SelectPFI3 = 4,
> >>>> kCDO_Update_Source_SelectPFI4 = 5,
> >>>> kCDO_Update_Source_SelectPFI5 = 6,
> >>>> kCDO_Update_Source_SelectPFI6 = 7,
> >>>> kCDO_Update_Source_SelectPFI7 = 8,
> >>>> kCDO_Update_Source_SelectPFI8 = 9,
> >>>> kCDO_Update_Source_SelectPFI9 = 10,
> >>>> kCDO_Update_Source_SelectRTSI0 = 11,
> >>>> kCDO_Update_Source_SelectRTSI1 = 12,
> >>>> kCDO_Update_Source_SelectRTSI2 = 13,
> >>>> kCDO_Update_Source_SelectRTSI3 = 14,
> >>>> kCDO_Update_Source_SelectRTSI4 = 15,
> >>>> kCDO_Update_Source_SelectRTSI5 = 16,
> >>>> kCDO_Update_Source_SelectRTSI6 = 17,
> >>>> kCDO_Update_Source_SelectAI_Start = 18,
> >>>> kCDO_Update_Source_SelectAI_Convert = 19,
> >>>> kCDO_Update_Source_SelectPXI_Star_Trigger = 20,
> >>>> kCDO_Update_Source_SelectPFI10 = 21,
> >>>> kCDO_Update_Source_SelectPFI11 = 22,
> >>>> kCDO_Update_Source_SelectPFI12 = 23,
> >>>> kCDO_Update_Source_SelectPFI13 = 24,
> >>>> kCDO_Update_Source_SelectPFI14 = 25,
> >>>> kCDO_Update_Source_SelectPFI15 = 26,
> >>>> kCDO_Update_Source_SelectRTSI7 = 27,
> >>>> kCDO_Update_Source_SelectG0_Out = 28,
> >>>> kCDO_Update_Source_SelectG1_Out = 29,
> >>>> kCDO_Update_Source_SelectAnalog_Trigger = 30,
> >>>> kCDO_Update_Source_SelectAO_Update = 31,
> >>>> kCDO_Update_Source_SelectFreq_Out = 32,
> >>>> kCDO_Update_Source_SelectDIO_Change_Detect_Irq = 33,
> >>>> } tCDO_Update_Source_Select;
> >>>>
> >>>> So, Stefan, here is a quick solution:
> >>>>
> >>>> if you have access to your board you can choose one of these signals
> >>>> (in which a regular pulse is occuring) and you can modify accordingly
> >>>> the field scan_begin_arg of the structure a4l_cmd_t in cmd_bits.c.
> >>>>
> >>>>>
> >>>>>> Best wishes,
> >>>>>>
> >>>>>> -Stefan
> >>>>>>
> >>>>>>
> >>>>>> On Jun 30, 2010, at 15:45, Alexis Berlemont wrote:
> >>>>>>
> >>>>>>> Hi,
> >>>>>>>
> >>>>>>> Stefan Schaal wrote:
> >>>>>>>> Hi Alexis,
> >>>>>>>>
> >>>>>>>> I did a reboot, ran my modified cmd_bits.c again one time.
> >>>>>>>>
> >>>>>>>> cat /proc/xenomai/irq reports:
> >>>>>>>>
> >>>>>>>> IRQ CPU0 CPU1 CPU2 CPU3 CPU4
> >>>>>>>> CPU5 CPU6 CPU7
> >>>>>>>> 56: 0 0 0 0 0
> >>>>>>>> 0 0 0 Analogy device
> >>>>>>>> 518: 0 1 1 1 1
> >>>>>>>> 1 1 1 [IPI]
> >>>>>>>> 521: 626392 618020 618539 620274 617326
> >>>>>>>> 625008 622464 626300 [timer]
> >>>>>>>> 522: 0 0 0 0 0
> >>>>>>>> 0 0 0 [critical sync]
> >>>>>>>> 546: 0 0 0 0 0
> >>>>>>>> 0 0 0 [virtual]
> >>>>>>>>
> >>>>>>>
> >>>>>>> I have not forgotten you. I am still stuck with your bug: The mite
> >>>>>>> transfers the first 8000 bytes and after does nothing; no interrupt is
> >>>>>>> generated by the mite so as to finally awake your application.
> >>>>>>>
> >>>>>>> It seems like the data retrieved by the mite are not consumed by the
> >>>>>>> board. Are you sure the digital output lines correspond to what you
> >>>>>>> configured with cmd_bits ?
> >>>>>>>
> >>>>>>> I think the digital output is misconfigured. I am working on it.
> >>>>>>>
> >>>>>>>>
> >>>>>>>> -Stefan
> >>>>>>>>
> >>>>>>>> On Jun 27, 2010, at 3:37, Alexis Berlemont wrote:
> >>>>>>>>
> >>>>>>>>> Hi,
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> Stefan Schaal wrote:
> >>>>>>>>>> Hi Alexis,
> >>>>>>>>>>
> >>>>>>>>>> thanks so much for the new analogy software. Here are some first
> >>>>>>>>>> observations:
> >>>>>>>>>>
> >>>>>>>>>> 1) cmd_bits.c works fine on our NI6250 board
> >>>>>>>>>>
> >>>>>>>>>> 2) however, a slightly modified version hangs -- I appended my
> >>>>>>>>>> cmd_bits.c to this email. All what I added is a for loop around
> >>>>>>>>>> the a4l_async_write() and a4l_snd_insn() commands, i.e., I wanted
> >>>>>>>>>> to trigger a write repeatedly. Look for the "sschaal" comment in
> >>>>>>>>>> my modified cmd_bits.c . After 32 iterations, cmd_bits hangs, no
> >>>>>>>>>> error messages in dmesg. Interesting, when I change your
> >>>>>>>>>> "trigger_threshold" variable from 128 to 256, my loop runs for 16
> >>>>>>>>>> iterations (other changes of the trigger threshold adjust the
> >>>>>>>>>> number of iterations I get in a similar way). Thus, it feels like
> >>>>>>>>>> there is a buffer which does not get reset after a4l_snd_insn() is
> >>>>>>>>>> called -- does this make sense?
> >>>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> Could you tell me if the mite triggered an interrupt ? Could you
> >>>>>>>>> send
> >>>>>>>>> a dump of cat /proc/xenomai/irq after having made the test program
> >>>>>>>>> hang ?
> >>>>>>>>>
> >>>>>>>>> Many thanks,
> >>>>>>>>>
> >>>>>>>>>> Best wishes,
> >>>>>>>>>>
> >>>>>>>>>> -Stefan
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>> On Jun 24, 2010, at 15:43, Alexis Berlemont wrote:
> >>>>>>>>>>
> >>>>>>>>>>> Hi,
> >>>>>>>>>>>
> >>>>>>>>>>> Alexis Berlemont wrote:
> >>>>>>>>>>>> Hi Stefan,
> >>>>>>>>>>>>
> >>>>>>>>>>>> Stefan Schaal wrote:
> >>>>>>>>>>>>> Hi Alexis,
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> I was just wondering whether the new "experimental" branch in
> >>>>>>>>>>>>> your git repository is something that can be tried already.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> No. Not yet. This branch is aimed at temporarily holding the
> >>>>>>>>>>>> corrections I am trying to do for the cmd_bits issue. It needs
> >>>>>>>>>>>> quite a
> >>>>>>>>>>>> lot of work and I have not finished yet.
> >>>>>>>>>>>>
> >>>>>>>>>>>> If you have a look at the commits in this branch, we will see
> >>>>>>>>>>>> many
> >>>>>>>>>>>> "(broken)".
> >>>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>> I just rebased the experimental branch into the branch analogy.
> >>>>>>>>>>> So,
> >>>>>>>>>>> starting from now, we should be able to properly use cmd_bits
> >>>>>>>>>>> with a
> >>>>>>>>>>> clone of my git repository.
> >>>>>>>>>>>
> >>>>>>>>>>> After having reworked the asynchronous buffer subsystem (and
> >>>>>>>>>>> having
> >>>>>>>>>>> fixed some oops in the NI driver and in the new code), cmd_bits
> >>>>>>>>>>> can
> >>>>>>>>>>> correctly communicate with the DIO subdevice.
> >>>>>>>>>>>
> >>>>>>>>>>> A command like "./cmd_bits 0xffff 0xffff" works on my
> >>>>>>>>>>> board. Unfortunately, I have not done the necessary to check the
> >>>>>>>>>>> digital output lines yet.
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>>> Best wishes,
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> -Stefan
> >>>>>>>>>>>>
> >>>>>>>>>>>> --
> >>>>>>>>>>>> Alexis.
> >>>>>>>>>>>
> >>>>>>>>>>> --
> >>>>>>>>>>> Alexis.
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>> ======================================================= cmd_bits.c
> >>>>>>>>>> ==================================================
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>> Alexis.
> >>>>>>>>
> >>>>>>>
> >>>>>>> --
> >>>>>>> Alexis.
> >>>>>>
> >>>>>
> >>>>> --
> >>>>> Alexis.
> >>>>
> >>>> --
> >>>> Alexis.
> >>>
> >>
> >> --
> >> Alexis.
> >
> >
> > _______________________________________________
> > Xenomai-core mailing list
> > Xenomai-core@gna.org
> > https://mail.gna.org/listinfo/xenomai-core
>
--
Alexis.
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