Can a Connect IQ Data Field connect and communicate with a running sensor that is already bonded with the watch?

3354617 said:

If this sensor is already bonded (paired) with the Garmin watch through its standard 'Sensors & Accessories' menu, will my Data Field's BLE/ANT code be able to establish a connection and communicate with it

No.

3354617 said:

or does the native connection prevent this?

Yes.

To clarify, the native connection prevents a Connect IQ app from connecting to a sensor itself (using the Ant module).

However, the AntPlus class can be used to communicate with sensors which are already natively connected, in a limited way:

- the AntPlus module only supports a limited set of sensors

- the AntPlus module constrains how you can communicate with those sensors

In other words, the Ant module allows a CIQ app to directly make a connection to any kind of ANT/ANT+ sensor and do anything it wants. The AntPus module allows a CIQ app to connect to a limited set of ANT+ sensors and communicate with them in a predefined way

Or as the dev docs put it:

https://developer.garmin.com/connect-iq/core-topics/ant-and-ant-plus/

Also, a new wrinkle added in CIQ 5.1.0 is the ability for CIQ apps to participate in the native sensor pairing process, meaning that when the user asks the system to scan for sensors in the native sensors menu, your app can also scan for its own sensors.

https://developer.garmin.com/connect-iq/core-topics/pairing-wireless-devices/ 

So a CIQ app can now manage its own sensors in the native menu, but I think it's still the case that a sensor can only be connected natively or with a CIQ app, not both at the same time [*].

[*] one exception is sensors that allow multiple ANT connections, like Stryd (which can be connected to as a foot pod, bike power meter, or as its own proprietary profile - but each of these connection types still only allows one connection each)