Sending speed (Type 11) to F9R/K via UBX-ESF-MEAS (0x10 0x02).

I know I have to use the “sendcustom” capability of the GNSS library but there does not seems be some missing information as to the payload.

Byte 0 to 3 is a U4 “time tag” but there is a whole other conversation about message reception timing via first byte reception or time mark. My understanding is “time tag” is not the same as the “the epoch in the receiver time frame” or is this the “the epoch in the receiver time frame” which seems redundant when the receiver is already doing this?

Starting at byte 6 there is a U2 “id” which says is it is “Identification number of data provider”…where do you get this?

Help on this would be appreciated.

Thanks

Bruce