These sources have published measurements but no stream points at them yet, so
they are stored and never analysed (overview §5.5). Assemble
a measuring point on the right — drag a source into an orientation slot, or
select it and click the slot — then Declare sends one
POST /mpoints per card (watch it in the browser's dev tools;
the body is built server-side in declare_payload.py).
The chip on each source is the axis the sensor reports (X/Y/Z, its own frame). Which of those is horizontal, vertical or axial depends entirely on how the sensor was bolted on — only whoever mounted it knows, which is why the H/V/A choice is yours here and cannot be computed. Record it in your own system too; the deployment stores it only as free-form stream metadata.
Every source the deployment has seen is attached or placed on a card. New hardware appears here as soon as it publishes (§5.5 step 2).