What should the data in Resfile be as the input to RetroTS.m?

Hi AFNI experts,
I am trying RetroTS.m to get the regressors for physiological correction.The original files(format: xxx.resp) of physiological noise were acquired via a Siemens 7t scanner. And files (in .txt format) with raw numbers were generated by removing words of head information in .resp files. And now I need to know what should the data be to be inputted to RetroTS:

  1. The raw numbers (.txt) are OK or some preprocessing is needed?
  2. How much should the data be inputted? From which time point to which time point?
  3. Raw numbers corresponding to each run should be inputted separately for each time run RetroTS.m or all of them can be inputted one time?
  4. What should I do if the number of raw resp data points were less than needed? My fMRI data has 120 TR s.The resp rate is 50HZ and TR length is 2S. So 120502 time points are needed. But there are only 11949 resp points left after the data points in the very beginning were excluded. The excluded data points were obtained before scanning.
    Thanks in advance!
    Yu