NAME

       sampler - sample data from HAL in real time

SYNOPSIS

       loadrt sampler depth=depth1[,depth2...]  cfg=string1[,string2...]

DESCRIPTION

       sampler  and  halsampler(1) are used together to sample HAL data in real time and store it
       in a file.  sampler is a realtime HAL component that exports HAL pins and creates  a  FIFO
       in  shared  memory.  It then begins sampling data from the HAL and storing it to the FIFO.
       halsampler is a user space program that copies data from the FIFO to stdout, where it  can
       be redirected to a file or piped to some other program.

OPTIONS

       depth=depth1[,depth2...]
              sets  the  depth  of  the  realtime->user  FIFO  that sampler creates to buffer the
              realtime data.  Multiple values of depth (separated by commas) can be specified  if
              you  need  more  than  one  FIFO  (for  example if you want to sample data from two
              different realtime threads).

       cfg=string1[,string2...]
              defines the set of HAL pins that sampler exports and later samples data from.   One
              string  must  be  supplied for each FIFO, separated by commas.  sampler exports one
              pin for each character in string.  Legal characters are:

              F, f (float pin)

              B, b (bit pin)

              S, s (s32 pin)

              U, u (u32 pin)

FUNCTIONS

       sampler.N
              One function is created per FIFO, numbered from zero.

PINS

       sampler.N.pin.M input
              Pin for the data that will wind up in column M of FIFO N (and in column  M  of  the
              output file).  The pin type depends on the config string.

       sampler.N.curr-depth s32 output
              Current number of samples in the FIFO.  When this reaches depth new data will begin
              overwriting old data, and some samples will be lost.

       sampler.N.full bit output
              TRUE when the FIFO N is full, FALSE when there is room for another sample.

       sampler.N.enable bit input
              When TRUE, samples are captured and placed in FIFO N, when FALSE,  no  samples  are
              acquired.  Defaults to TRUE.

PARAMETERS

       sampler.N.overruns s32 read/write
              The  number of times that sampler has tried to write data to the HAL pins but found
              no room in the FIFO.  It increments whenever full is true, and can be reset by  the
              setp command.

       sampler.N.sample-num s32 read/write
              A  number  that  identifies  the  sample.  It is automatically incremented for each
              sample, and can be reset using the setp command.  The sample number can  optionally
              be  printed in the first column of the output from halsampler, using the -t option.
              (see man 1 halsampler)

SEE ALSO

       halsampler(1) streamer(9) halstreamer(1)

HISTORY

BUGS

AUTHOR

       Original version by John Kasunich, as part  of  the  LinuxCNC  project.   Improvements  by
       several other members of the LinuxCNC development team.

REPORTING BUGS

       Report bugs to jmkasunich AT users DOT sourceforge DOT net

COPYRIGHT

       Copyright © 2006 John Kasunich.
       This  is  free software; see the source for copying conditions.  There is NO warranty; not
       even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.