6. Bring-up & testing

Staged checks before club traffic. Pick the section for your central.

Central	Path	Section
DR5000	`loconet_serial` + Uhlenbrock 63120	§6.2–§6.4
RB1110 / RB1110-Mini	`z21`	§7.6
Other Z21 + LocoNet	Either (best-effort)	§7 + relevant section below

6.1 Host platform (all paths)

Pi 5 boots from NVMe (M.2 HAT+) — hub image (§8) or Pi OS (§3).
PREEMPT_RT / isolcpus per §8.6 or §3.3.
BigFred deployed; Redis + supervisord per architecture docs.
DR5000 only: user in dialout, udev for Uhlenbrock 63120 (§3.5).
RB1110 only: Pi and central on same LAN; RB1110 IP documented.

6.2 Uhlenbrock 63120 (DR5000 only)

DR5000 on; Uhlenbrock 63120 on LocoNet-T (not LocoNet-B).
LocoNet LED blinks on activity (solid = no bus — fix before LNCV).
LNCV 2 = 3 (57600), LNCV 4 = 1 (Direktmodus) — LocoNet-Tool or rb lncv (§6.2.1).
Uhlenbrock 63120 on USB 3; ls -l /dev/loconet-63120 (or ttyUSB0 / ttyACM0).
Close serial monitors before dcc-bus.

6.2.1 LNCV via `rb lncv` (Linux)

Factory USB baud is 115200 until LNCV 2 is changed. Use --self-config for adapter CV2/CV4 (no acknowledge on the wire).

rb lncv get --device /dev/ttyUSB0 --baud 115200 --article 63120 --addr 1 0
rb lncv set --self-config --device /dev/ttyUSB0 --baud 115200 --article 63120 4 1
rb lncv set --self-config --device /dev/ttyUSB0 --baud 115200 --article 63120 2 3
rb lncv get --device /dev/ttyUSB0 --baud 57600 --article 63120 2
rb lncv get --device /dev/ttyUSB0 --baud 57600 --article 63120 4

Details: §4.2.1.

6.3 Manual serial sanity (DR5000, optional)

stty -F /dev/loconet-63120 57600 cs8 -cstopb -parenb raw
timeout 5 xxd /dev/loconet-63120

Expect bus traffic; 83 7C is a common valid frame. Garbage at 115200 → LNCV.

6.4 BigFred end-to-end — LocoNet (DR5000)

loconet_serial command station (§5.3).
dcc-bus starts without open ... errors.
setSpeed moves a loco; physical throttle reflected in UI.
Two browser drivers, two locos.

6.5 Troubleshooting — LocoNet path

Symptom	Likely cause	Action
No `/dev/ttyACM` / `ttyUSB`	USB / PSU	Data cable; 27 W PSU; `dmesg`
`permission denied`	dialout / udev	Fix group and rules
LocoNet LED solid, no blink	No bus traffic	Central on; LocoNet-T; RJ12 cable; bus power
`rb lncv`: no bytes received	Dead bus or wrong baud	Fix LED/bus; match `--baud` to LNCV 2
`rb lncv get` works once, then silent	Programming session stuck	Power-cycle 63120; `rb lncv` always sends prog-end
`rb lncv set` timeout (no `--self-config`)	Module busy / write rejected	Retry; use `--self-config` for adapter CV2/CV4
`xxd` shows nothing (exit 124)	Idle bus or dead bus	Normal if central idle; if LED solid → wiring
Random hex	LNCV	57600 + Direktmodus
`bad checksum`	Bus / baud	LNCV; 62280; shorter run
Commands time out	Central off / wrong port	LocoNet-T
Works on DR5000 USB, not Uhlenbrock 63120	T-bus segment	Power/signal on branch

6.6 Troubleshooting — Z21 path

See §7: wrong IP, firewall UDP 21105, VLAN, competing Z21 client (mobile app).

6.7 Acceptance checklist

Host (both)

[ ] NVMe partitions per §8.4 (or Pi OS NVMe root); RT / isolcpus documented.
[ ] Hub image: boot under 10 s, watchdog and fanctl running (§8.11).
[ ] rotate-hub-logs and crontab present (§8.9).

DR5000 + Uhlenbrock 63120

[ ] LNCV 57600 + Direktmodus; stable /dev/loconet-63120.
[ ] LocoNet-T; two web drivers on one Uhlenbrock 63120.

RB1110

[ ] Catalogue z21; UDP socket open in logs.
[ ] setSpeed + physical throttle reflection + two drivers — §7.6.

Dual-protocol (unsupported guarantee)

[ ] Model, firmware, and chosen kind (z21 vs loconet_serial) recorded in runbook.

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