 A value of zero allows the remaining frames to be sent without flow control or delay.The third byte is the Separation Time (ST), the minimum delay time between frames.ST values up to 127 (0x7F) specify the minimum number of milliseconds to delay between frames, while values in the range 241 (0xF1) to 249 (0xF9) specify delays increasing from 100 to 900 microseconds.