Hi,
Catalyst does utilize Trimble CenterPoint RTX.
In the following I'm assuming you are using the Trimble Correction Hub as correction service and have either a Precision, Decimeter or Sub-meter subscription.
The way it works is that Catalyst first checks if a local VRSNow network is available at your current location. If so: good - otherwise plan B kicks in meaning Catalyst goes for RTX via IP. The IP stream is the 'full' RTX IP stream including localized ionospheric corrections (so CenterPoint RTX Fast) assuming its available at your location.
A detailed map on on CenterPoint etc can be found here: CenterPoint RTX .
If you are in a fast region you typically get down to a decimeter level accuracy.
If you are in a none-fast region you get typically values in the sub-meter domain.
Further or detailed infos can be found in the coverage area as linked on the Catalyst web site.
Assuming you have an active internet connect you will get the data stream, otherwise Catalyst goes to plan C which is RTX via Satellite. The SV stream now depends on your location.
So this is the default behavior of the Catalyst system when you connect to the antenna; depending on the software those 'jumps' between correction types may also occur while using the system. This depends on the application and if the 'jumps' are wanted or not.
If you configured a custom NTRIP correction source the assumption is that you also want to use this source - so applications like Trimble Mobile Manager do not go for plan B and C in case of custom NTRIP. It is technically possible via utilizing the - but not the default behavior for simple apps like TMM.
Hope this makes sense.