How can I supply power to the modules?
TE0300: Power can be supplied via USB or the B2B connector. You can apply both at once, but the B2B will take precedence then. There will be no backcurrent from B2B to USB.
TE0320: You can either power via USB, or via B2B. The Powersource is an assembly option, there is no automatic switchover. Please see the manual for more details. Powering this module via USB is only useful for small designs.