Dear Qiaoquin Wang,
the FS0B reply time cannot be changed. Only conditions when the FS0B will be asserted can be set. Please refer to section 12.5.5, Table 86. the WD_IMPACT_1:0 bits in INIT_SF_IMPACT register, section 12.5.3 and Figure 25 in the datasheet.
Did you mean the delay time tdelay of the FS1B?
The delay between FS0B and FS1B activation is configurable via the SPI from 0 ms to
3150 ms with the combination of FS1B_TIME_3:0 and FS1B_TIME_RANGE bits. This
digital delay is generated by the fail-safe logic with an accuracy of ±10 %. FS1B can be
activated at the same time as FS0B if tDELAY = 0 or after a programmable delay if tDELAY
> 0.
For the tdelay configuration please refer to the Table 76. in the datasheet.
Regarding the FTTI, I couldn't find a description of it in the datasheet. Could you please explain the FTTI abbreviation?
With Best Regards,
Jozef
