# Peers

# Peers

Run one test across two machines. On the **Peers** tab, pair the other device:
find it or enter its address, read the **fingerprint** aloud to confirm, and
approve. That opens a secure link.

Then read and command its channels with `peer=`:

```python
ch.read("/dut/signal", unit="V", peer="rig-b")                # its telemetry
ch.write("/out/enable", dtype="bool", peer="rig-b")           # command it
```

Two rules keep it safe:

| Rule | Why |
|---|---|
| **Safety stays local** | [Interlocks](https://phloem.ai/docs/trellis/interlocks/) use only your channels, so your hardware trips safe even if the peer drops |
| **Peer commands live in procedures** | you can command another device only in a [procedure](https://phloem.ai/docs/trellis/sequences/) step: explicit and supervised, never automatic |

Each machine keeps its own safety.