Hello Florian,
Just for information. The chapter 8, page 8-7 of DAQ X Series user manual (August 2010) says that the high impedance states (also default) are possible for both PFI and DIO lines, but as I have tried following your suggestions, it is possible only for DIO and not for PFI.
Secondly, once the task has stopped, the PFI port either goes in low or hogh state. No change is also not possible which means that in order to get a continous pulse frequency, one must keep the task running. It would be great if this is made available in future versions, because one can not run other PFI taks if one taks is already running.
In brief following states are possible for DIO ports, but only the first 2 for PFI ports:
#define DAQmx_Val_High 10192 // High
#define DAQmx_Val_Low 10214 // Low
#define DAQmx_Val_Tristate 10310 // Tristate
#define DAQmx_Val_NoChange 10160 // No Change
Regards
RB
