# Operating mode: HyBBX Host

Secondary RF host on a HyBBX **Secondary** node — or **standalone Main** cohost when `[instance] standalone=yes` and max25d `mode=hybbx-cohost`. MAX25 prepares hardware; HyBBX bridges AX.25 to Main over HBX (Secondary) or serves users locally (standalone Main).

## Workflow

1. MAX25 device prep (boot-wait, `max25-bcpr-ctl start`, or `crdopc`)
2. max25d releases KISS PTY (`/tmp/max25-bcpr/kiss-bc0` for BayCom/based)
3. Merge `share/hybbx/*-host.ini.example` into `hybbx.ini`
4. Start HyBBX (Secondary or standalone Main)

## Per device

| Device | MAX25 prep | HyBBX plugin |
|--------|------------|--------------|
| TNC2C | `tnc2c-boot-wait.sh` | `packet_radio` |
| BayCom/based SER12 | `max25-bcpr-ctl start` / max25d `max25_bcpr=yes` | `baycom` |
| CRDOP | `crdopc` running | `crdop` |

**Co-host Main:** dual TNC + PC-COM on one host — max25d `mode=hybbx-cohost`, HyBBX `[networks] baycom=yes`. See [docs/BAYCOM.md](../../docs/BAYCOM.md).

Contract: [docs/HYBBX.md](../../docs/HYBBX.md)