DRV2605L: [DRV2605L] About the Waveform Library

When I saw the datasheet about Waveform sequencer, 

it described that when I set the bit 7 (Wait bit) for Waveform Sequencer, WAV_FRM_SEQ[6:0] bit will be interpreted as a wait time. It means that each sequence register can implement a delay between sequence waveforms. 

But when I used the DRV2605L sparkfun haptic motor driver library to adjust waveform function as below : 

voidSFE_HMD_DRV2605L::Waveform(uint8_t seq, uint8_t wav) {

    writeDRV2605L(WAVESEQ1+seq,wav);

}

Then I made my own code to adjust the delay time... like this way :

SFE_HMD_DRV2605.Waveform(128,1);

SFE_HMD_DRV2605.Waveform(128,123);

SFE_HMD_DRV2605.go();

But it doesn't make any change between the sequence, and there is no change in vibration pattern. 

So, I just want to know the definition of delay time and how to change this. 

Also, if there is any reference to measure the signal of I2C communication between Arduino & DRV2605L by using oscilloscope, please let me know.