[ Oops! I somehow thought you were using Win32::API and not XS. Ignore this. ]

use feature qw( say state );

use Win32::API qw( );

use constant {
   _MAX_PROTOCOL_LEN => 25,
   _MAX_MODEL_LEN    => 25,
};

use constant {
   TELLSTICK_SUCCESS => '~~~',
};

sub tdSensor {
   state $tdSensor = Win32::API->new(
      '~~~.dll',
      'tdSensor',
      'PIPIPP',
      'I',
   );

   my $protocol_buf  = "\0" x (_MAX_PROTOCOL_LEN + 1);
   my $model_buf     = "\0" x (_MAX_MODEL_LEN + 1);
   my $id_buf        = pack('i', 0);
   my $dataTypes_buf = pack('i', 0);

   my $rv = $tdSensor->Call(
      $protocol_buf, length($protocol_buf),
      $model_buf, length($model_buf),
      $id_buf,
      $dataTypes_buf,
   );

   if ($rv != TELLSTICK_SUCCESS) {
      return undef;
   }

   return {
      protocol  = unpack('Z*', $protocol_buf),
      model     = unpack('Z*', $model_buf),
      id        = unpack('i', $id_buf),
      dataTypes = unpack('i', $dataTypes_buf),
   };
}


while (my $rec = tdSensor()) {
   say join ', ',
      "protocol: $rec->{protocol}",
      "model: $rec->{model}",
      "sensorId: $rec->{id}",
      "dataTypes: $rec->{dataTypes}";
}
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Untested. Assumes a 32-bit build of Perl.