Scan time

Dear Members,

I have few basic questions. I am using Philips 1.5T  for rsfMRI. I have scanned a subject for 8 min. I have given the details of aquisition parameters below. When TR is 2sec and scan time is 8 min (480 sec) the total volume should be 240. But I am getting only 120 volumes of images. Could you plz explain where I am going mistake or any other parameter affecting the scan time?

"Repetition time (ms): 2000
Echo time[0] (ms): 
Echo time[1] (ms): 45
Inversion time (ms): 
Flip angle: 70
Number of averages: 1
Slice thickness (mm): 4
Slice spacing (mm): 4
Image columns: 64
Image rows: 64
Number of frames: 
Phase encoding direction: COL
Voxel size x (mm): 3.4375
Voxel size y (mm): 3.4375
Number of volumes: 120
Number of slices: 35
Number of files: 4200
Number of frames: 0
Slice duration (ms) : 0
Volume interval (s): 4
Orientation: tra"