man comedi_dio_bitfield (Fonctions bibliothèques) - read/write multiple digital channels
NAME
comedi_dio_bitfield - read/write multiple digital channels
SYNOPSIS
#include <comedilib.h> int comedi_dio_bitfield (comedi_t * device, unsigned int subdevice, unsigned int write_mask, unsigned int * bits);
DESCRIPTION
The function comedi_dio_bitfield() allows multiple channels to be read simultaneously from a digital input or digital I/O device. The parameter write_mask and the value pointed to by bits are interpreted as bit fields, with the least significant bit representing channel 0. For each bit in write_mask that is set to 1, the cooresponding bit in *bits is written to the digital output channel. After writing all the output channels, each channel is read, and the result placed in the approprate bits in *bits. The result of reading an output channel is undefined. It is not possible to access channels greater than 31 using this function.