ni_do

Brief: Class for streaming buffered digital positions output by NI PCI-6534 board.

This allows you to stream out 32bit digital positions from a buffer. You can do so either timed by an external request trigger or by an internally chosen timebase. In particular the device is being configured to stream positions to the Delta Tau PMAC.

Public member functions:

• C++ constructor
  ni_do()
• C++ destructor
   ni_do()

• This routine should be called before anything else is done. It establishes contact whith the NI PCI-6534 board and sets some of the parameters to our desired values.
  int init_device(log_err *p_log_err)

• This routine sets the board to advance from pixel to pixel based on an external clock input into the REQ1 line (such as in stepper motor scans).
  int select_external_clock(log_err *p_log_err)

• This routine sets the board to advance from pixel to pixel based on an internal timebase with a pixel time of fDwellTime in ms (such as for piezo scans).
  int select_internal_clock(F32 fDwellTime,log_err *p_log_err)

• This routine starts the output of position values stored in psBuffer based on clock signals.
  int start_buffer_output(I16 *psBuffer,U32 ulNumScans,
  log_err *p_log_err)

• This routine checks if a scan is done. It returns 0 if the scan is complete, 1 if not and -1 if there was an error. One can compare the value in pulRemaining with the number of positions loaded to the board.
  int buffer_output_status(U32 *pulRemaining,log_err *p_log_err)

• This routine stops the buffered output due to internal or external triggers. Call it, if you want to abort a scan. (You can also call it for safety in case of normal termination.)
  int stop_buffer_output(log_err *p_log_err)

• This routine shuts down the device.
  int close_device(log_err *p_log_err)