... comedi_data_read -- read single sample from channel . ... int comedi_data_read (comedi_t * device, unsigned int subdevice, unsigned int channel, unsigned int range, unsigned int aref, lsampl_t * data); . Reads a single sample on the channel specified by the Comedi device device, the subdevice subdevice, and the channel channel. ... The function comedi_data_read() reads one data value from the specified channel and places the data value in the location pointed to by data. ... comedi_data_write ...