Smart TX power only support 6.8Mbps Data Rate?

when the data rate is 110kbps or 850kbps,the smart tx power will not work?so if I want to take smart tx mode,I have to make the data rate 6.8Mbps???? is that right ?

Yes, Smart TX is only meaningful for short frames (frames smaller than 1 ms). If your frame is longer than 1ms, which is probable with slower rates, you can not increase power.

Alternatively, you can set the TX power differently for each frame.

So , if I set the Data Rate is 110kbps,but I make the frame less than 1ms. the smart tx is still meaningful. Rihgt???

I make it that the absolute minimum length for a 110 kbps packet us 893 us. That’s close enough to 1 ms that there isn’t any meaningful power boost possible.

Also it makes no sense to send a frame with a 110 kbps but a short preamble. If the medium is good enough to detect the frame with a short preamble, you can use faster rate.