comedi_get_cmd_generic_timed man page
comedi_get_cmd_generic_timed — streaming input/output capabilities
int comedi_get_cmd_generic_timed (comedi_t * device, unsigned int subdevice, comedi_cmd * command, unsigned int chanlist_len, unsigned int scan_period_ns);
The command capabilities of the subdevice indicated by the parameters device and subdevice are probed, and the results placed in the command structure pointed to by the parameter command. The command structure pointed to by the parameter command is modified to be a valid command that can be used as a parameter to comedi_command() (after the command has been assigned a valid chanlist array). The command measures scans consisting of chanlist_len channels at a scan rate that corresponds to the period scan_period_ns. The rate is adjusted to a rate that the device can handle. If sucessful, 0 is returned, otherwise -1.