Commedi command inside RTAI fifo

[R Leao]

Hi All,
I want to do a single sample scan through 8 channels of my DAQ board and
I want it to be repeated through a FIFO in an RTAI module. I need it to
be looped because I want to do a real time window discriminator (based
on the amplitude of the signal in each input). The RTAI module peace of
code

looks like this:
> > >
> > > static void fun(int t)
> > > {
> > >  char buf[N_CHANS];
> > >  for(i=0;i<n_chan;i++){
> > >   chanlist[i]=CR_PACK(chan+i,range,aref);
> > >  }
> > >         cmd->chanlist  = chanlist;
> > >         cmd->chanlist_len = n_chan;
> > >
> > >         cmd->scan_end_arg = n_chan;
> > >  if(cmd->stop_src==TRIG_COUNT)cmd->stop_arg = n_scan;
> > >
> > >  /* the subdevice that the command is sent to */
> > >         cmd->subdev = subdevice;
> > >  /* flags */
> > >         cmd->flags = 0;
> > >         cmd->start_src = TRIG_NOW;
> > >         cmd->start_arg = 0;
> > >         cmd->scan_begin_src = TRIG_TIMER;
> > >         cmd->scan_begin_arg = (int)(1e9/freq);
> > >         cmd->scan_end_src = TRIG_COUNT;
> > >         cmd->scan_end_arg = n_chan;  /* number of channels */
> > >         cmd->stop_src =  TRIG_COUNT;
> > >         cmd->stop_arg =  n_scan;
> > >         cmd->chanlist =  chanlist;
> > >         cmd->chanlist_len = n_chan;
> > >         ret = comedi_command_test(device,cmd);
> > >
> > >         while (1) {
> > >         ret=comedi_command(device,cmd);
> > >         ret=read(comedi_fileno(device),buf,N_CHANS);
> > >         counter=data[2];
> > >         pdatab=2;
> > >
> > >         rtf_put(FIFO, &ret, sizeof(ret));
> > >         rtf_put(FIFO, &pdatab, sizeof(pdatab));
> > >         rt_task_wait_period();
> > >         }
> > > }
> > >
> > >
It compiles OK but when I try to run, it says:
> > > insmod: error inserting 'myrt_process.ko': -1 Unknown symbol in
module
> > > ERROR: cannot load myrt_process.ko
> > >
> > > I have the following relevant modules loaded:
> > >
> > > Module                  Size  Used by
> > > ni_pcimio              48768  0
> > > mite                    6148  1 ni_pcimio
> > > comedi_rt_timer         7424  0
> > > comedi_fc               3072  2 ni_pcimio,comedi_rt_timer
> > > 8255                    5248  1 ni_pcimio
> > > kcomedilib             12544  1 comedi_rt_timer
> > > comedi                 31488  5
> > > ni_pcimio,comedi_rt_timer,comedi_fc,8255,kcomedilib
> > > rtai_shm                9600  0
> > > rtai_fifos             38220  0
> > > rtai_lxrt              72880  5
> > > ni_pcimio,comedi_rt_timer,kcomedilib,rtai_shm,rtai_fifos
> > > rtai_math              27780  0
> > > rtai_up                53776  0
> > > rtai_hal               21364  6
> > > ni_pcimio,kcomedilib,comedi,rtai_fifos,rtai_lxrt,rtai_up
> > >
> > >
> > > Am I missing any module to be loaded if I use the comedi command?
This
> > > little module works fine if I use 'comedi_data_read'. Thanks all.

dmesg says that:

myrtprocess: unkown symbol read

Any help would be extremely appreciated.

Thank you!
-- 
R Leao <richardson.leao at anu.edu.au>
JCSMR, Australian National University