[time-nuts] Ublox neo-7M GPS

[Tony]

On 21/08/2014 08:13, Ed Palmer wrote:
> But, timing receivers do have features that can improve performance 
> over navigation receivers. Some that come to mind are position hold 
> mode, TRAIM, maintaining performance with only one satellite locked, 
> sawtooth correction, and precision survey.  I haven't dug through the 
> Ublox data sheets to see which ones they support.

I just tried sending various TMODE and TMODE2 configuration messages to 
the NEO-7M. These allow you to select 'Disabled' 'Survey In' and 'Fixed 
Mode' where you can specify the receiver's lattitude and longitude. Not 
surprisingly, it replied with negative acknowledgements each time so 
they presumably aren't supported in this receiver. I was using the ublox 
u-center tool which should ensure the messages were formatted correctly. 
It's very unlikely, but its conceivable that it does actually support 
these modes but some other required configuration hadn't been done, 
causing a conflict.

I've not yet found any detailed documentation specifying exactly which 
messages/features these modules do support.

Tony H