wb-serial

name: wb-serial description: "Serial bus (RS-485/Modbus) on WB — custom templates, adding devices via confed, and diagnostics: CRC errors, timeouts, device not responding, slow polling, bus scan, health check." allowed-tools: Bash Read Write WebFetch WebSearch

wb-serial

CRITICAL RULES

NEVER call wb-cli without --json from an agent. Human-mode output is unparseable; always use: wb-cli --json <command> This applies to every call including help: wb-cli --json <group> --help.

<HOST> variable: in all examples below <HOST> means wirenboard-<SN>.local, where <SN> is the serial number (e.g. wirenboard-AABBCCDD.local). Substitute the real address.

When to load this skill

• Templates: "no template for the device", "add a third-party Modbus device", "create a template", "how to add custom registers", "template for an energy meter", "Modbus thermometer".
• Diagnostics: Modbus errors, CRC, timeouts, "device not responding", "data not updating", slow polling, read/write errors.

IMPORTANT for diagnostics: Act without pauses. DON'T ask permission for each step — the user ALREADY asked for diagnostics. Execute ALL steps in sequence: logs → debug → scan → health. DON'T stop with questions like "want to run debug?" — just do it. Report at the end.

wb-cli — primary tool

wb-cli serial wraps every wb-mqtt-serial / wb-device-manager RPC the diagnostics flow needs; prefer it to raw MQTT RPCs.

ssh root@<HOST> wb-cli --json serial wb-scan --port /dev/ttyRS485-1     # bus scan (Fast Modbus)
ssh root@<HOST> wb-cli --json serial wb-scan --slow --timeout 300       # exhaustive UART poll
ssh root@<HOST> wb-cli --json serial wb-scan --bootloader               # devices in bootloader mode
ssh root@<HOST> wb-cli --json serial config                            # what's in /etc/wb-mqtt-serial.conf
ssh root@<HOST> wb-cli --json serial ports                              # ports the driver currently serves
ssh root@<HOST> wb-cli --json serial fw-params 52                   # current firmware settings
ssh root@<HOST> wb-cli --json serial fw-params 52 in0_mode=1     # update firmware settings
ssh root@<HOST> wb-cli --json serial-debug --port /dev/ttyRS485-1 --seconds 60
ssh root@<HOST> wb-cli --json dev wb-mr6c_52                            # live values from the device

MQTT RPC via Bash — base pattern (fallback)

Use only for RPCs that wb-cli does not yet wrap (custom drivers, ad-hoc exploration). Anything covered by wb-cli serial … should go through wb-cli.

ssh root@<HOST> 'CID=ai-$(date +%s)-$(head -c4 /dev/urandom | od -An -tx1 | tr -d " "); mosquitto_sub -t "/rpc/v1/<driver>/<service>/<method>/$CID/reply" -C 1 -W <timeout> & sleep 0.2; mosquitto_pub -t "/rpc/v1/<driver>/<service>/<method>/$CID" -m '"'"'{"id":1,"params":{...}}'"'"'; wait'

Part 1 — Templates and device configuration

Where templates live

wb-mqtt-serial scans both directories at start. A custom template with the same device_type as a packaged one overrides the packaged one.

For the full template JSON layout (minimal example, channel fields, parameters, groups, translations, endianness, string/varstring) — see references/template-format.md.

For the 6-step creation workflow, the fw-params read/write flow, listing devices and ports, and device firmware-version lookup — see references/template-workflow.md.

Adding a device to wb-mqtt-serial

CRITICAL: NEVER edit /etc/wb-mqtt-serial.conf manually or via raw confed API. wb-mqtt-serial templates have required parameters that must be present in the config. Missing them causes config validation failure → ports/Load returns [] → all bus scans stop working until the config is fixed. Always use wb-cli serial add-devices — it fills required params from template defaults automatically.

Standard workflow: scan → add

# Extended scan (WB Fast Modbus devices — default, fast)
ssh root@<HOST> wb-cli --json serial wb-scan

# Slow scan (third-party devices without Fast Modbus support)
ssh root@<HOST> wb-cli --json serial wb-scan --slow --timeout 300

# Add all found devices across every port the scan touched (one call)
ssh root@<HOST> wb-cli --json serial add-devices

# Or limit to a single port
ssh root@<HOST> wb-cli --json serial add-devices --port /dev/ttyRS485-1

add-devices reads the retained wb-device-manager state — so you can run any scan type (extended or slow) and then add without re-scanning. Devices already in config are skipped.

Add a single device by model (no scan needed)

ssh root@<HOST> wb-cli --json serial add-devices \
  --port /dev/ttyRS485-1 --device-type WB-MAI6 --slave-id 19

For the automatic-fixups table (baud, duplicate slave_id, conflict resolution) and the add-devices result shape — see references/template-workflow.md.

Bus-level writes — slave_id and baud rate

WB devices expose two bus-level registers that aren't template parameters — slave_id (reg 128) and baud rate / 100 (reg 110). Dedicated wb-cli shortcuts:

# Change a device's slave_id
ssh root@<HOST> wb-cli --json serial wb-set-slave-id 5 19 --port /dev/ttyRS485-1

# Collision-safe via WB Fast Modbus by SN (no need to know the current address)
ssh root@<HOST> wb-cli --json serial wb-set-slave-id 5 19 --port /dev/ttyRS485-1 --sn 0x00020B86

# Change baud rate; speak to the device at its current baud
ssh root@<HOST> wb-cli --json serial wb-set-baud 5 9600 --port /dev/ttyRS485-1 --baud 19200

Caveat — WB-only. Both use the WB Common Modbus Registers convention. Won't work for non-Modbus devices on the same RS-485 (Энергомера IEC-61107, DOOYA) or third-party Modbus devices that change slave_id via a different register. The add-devices baud-fixup and address-collision recovery use the same internally, so they're also WB-only.

Sending raw Modbus PDUs

# Read 1 holding register (FC3, reg 110)
ssh root@<HOST> wb-cli --json serial send-modbus --port /dev/ttyRS485-1 --slave 5 --fc 3 --reg 110

# Read 10 input registers from a third-party device at 19200
ssh root@<HOST> wb-cli --json serial send-modbus --port /dev/ttyRS485-1 --slave 12 --fc 4 \
    --reg 0 --count 10 --baud 19200

# Write a single holding register (FC6)
ssh root@<HOST> wb-cli --json serial send-modbus --port /dev/ttyRS485-1 --slave 5 --fc 6 \
    --reg 128 --value 19

Supports FC3 / FC4 / FC6. For Fast Modbus or other FCs use raw serial send. For Modbus devices only; non-Modbus protocols won't answer.

Firmware update — serial wb-fw

ssh root@<HOST> wb-cli --json serial wb-fw check 4 --port /dev/ttyRS485-1          # one device
ssh root@<HOST> wb-cli --json serial wb-fw check                                    # every device
ssh root@<HOST> wb-cli --json serial wb-fw update 4 --port /dev/ttyRS485-1 --wait   # flash blocking
ssh root@<HOST> wb-cli --json serial wb-fw update --all --background \
    --output /mnt/data/ai/wb-cli/fw-$(date +%s).json                                # flash all in background
ssh root@<HOST> wb-cli --json serial wb-fw restore 4 --port /dev/ttyRS485-1 --wait  # recover stuck bootloader
ssh root@<HOST> wb-cli mqtt sub /wb-device-manager/firmware_update/state            # progress feed

Loading / testing without restart

ssh root@<HOST> 'systemctl restart wb-mqtt-serial'
ssh root@<HOST> 'journalctl -u wb-mqtt-serial -n 50 --no-pager | grep -iE "(template|<device.id>)"'

Part 2 — Diagnostics

Start with this — 7-step sequence

1. Documentation — WebFetch("https://wirenboard.com/wiki/<DeviceModel>") for "Known issues"; if nothing — WebSearch("site:wirenboard.com/wiki/ <DeviceModel> <error>"). Always cite the URL.

2. Driver alive? ssh root@<HOST> "systemctl is-active wb-mqtt-serial".

3. Logs — count + tail + histogram by slave_id:

   ssh root@<HOST> "journalctl -u wb-mqtt-serial -p warning --since '1 hour ago' --no-pager | wc -l; echo ---; journalctl -u wb-mqtt-serial -p warning --since '1 hour ago' --no-pager | tail -30"
   ssh root@<HOST> "journalctl -u wb-mqtt-serial -p warning --since '1 hour ago' --no-pager | grep -oP 'device modbus:\\K\\d+' | sort | uniq -c | sort -rn"
   

4. Debug — raw packets. RUN IMMEDIATELY, DON'T ASK. Duration depends on error rate from step 3:

   ssh root@<HOST> wb-cli --json serial-debug --port /dev/ttyRS485-1 --seconds <DURATION>
   

   For the duration heuristic table, the long-capture wrapping in a wb-cli job, and the Debug post-condition check — see references/diagnostics-deep.md.

5. Bus scan — wb-cli --json serial wb-scan --port /dev/ttyRS485-1 (Fast Modbus) or --slow for third-party. serial ports for active ports.

6. WB device health — uptime regs 104-105, supply / min voltage regs 121-122 on relays/dimmers/MCM.

7. Save the report to /mnt/data/ai/wb-ai-skills/diag/serial-diag.txt.

For full step bodies (debug-duration table, raw-packet capture wrapping, health-check commands, save-the-report snippet) — see references/diagnostics-deep.md.

For the saw → do patterns table, the tools section (modbus_client_rpc, device/Probe, wb-modbus-scanner, modbus_client), the useful WB device registers table, and experiments (stop bits, speed, isolation, timeouts) — also in references/diagnostics-deep.md.

Fast Modbus (WB extension protocol)

WB devices support a Modbus-RTU extension that adds: scan-by-SN, targeted-PDU-by-SN (for slave_id collisions), and event push (low-latency diagnostics). All frames use broadcast address 0xFD and command byte 0x46. Use it when scan finds two devices with the same slave_id, or when a device is in scan but unresponsive to modbus_client_rpc.

For the frame types table, exact byte sequences (change slave_id by SN, change baud by SN), the port/Load RPC envelope, and when-to-use guidance — see references/fast-modbus.md.

Pitfalls

• Template in /usr/share/wb-mqtt-serial/templates/ — overwritten on upgrade. Only /etc/wb-mqtt-serial.conf.d/templates/.
• Endianness — most common error for u32/s32/float. If the value jumps by a 65535 factor — word_order: little_endian.
• Scale in the wrong direction — test on one channel.
• Duplicate device_type — silently overrides packaged template. Use a prefix like ACME-.
• Cyrillic in device.id — forbidden (goes into topic name). Only [a-z0-9-].
• Address 0-based vs 1-based — check the device spec.
• No error_value — if device returns FFFF for "no data", MQTT will show 65535 as valid.
• modbus_client/wb-modbus-scanner without stopping the driver → false errors.
• Forgotten debug → disk fills up.
• Wrong baud → COMPLETELY silent. Wrong stop bits → floating errors.
• RS-485 in star topology works on short distances; for issues — recommend daisy chain.

What the agent does NOT do

• Edit /etc/wb-mqtt-serial.conf manually (or via raw confed API). Use wb-cli serial add-devices — it fills required template params from defaults; manual edits cause ports/Load to return [] and break all bus scans.
• Run modbus_client / wb-modbus-scanner while wb-mqtt-serial is active. They contend for the same port → false errors. Stop the driver first (agree with the user — that pauses ALL polling).
• Leave debug mode on after a diagnostic capture. wb-cli serial-debug restores it automatically; raw-restart flows must re-disable explicitly or the journal fills the disk.
• Use slave_id 0 outside of the specific broadcast write for "change baud/address for ALL WB devices at once". Slave_id 0 = broadcast — every device responds (or none reply).
• Pick word_order: little_endian by default. Modbus byte order is big-endian — only override when a multi-register value is observably wrong (jumps by 65535×).
• Override a packaged template by reusing its device_type. Custom templates with the same device_type silently win; use a prefix (ACME-, BIDIR-) to avoid confusion.

When to ask the user

• About to broadcast-write reg 110 or 128 (slave_id 0) — confirm; this hits every WB device on the bus.
• About to firmware-update a device while production polling is happening on the same bus — confirm the timing window.
• Experiments (stop bits, baud, port timeouts) — confirm the rollback plan; back up /etc/wb-mqtt-serial.conf first.
• Adding a custom protocol (non-Modbus) device to the same port as Modbus devices — confirm the per-device polling priorities; non-Modbus drivers can block Modbus scans.
• A scan shows duplicate slave_ids — surface the candidates and confirm which one keeps the address.
• About to enable a heavy polling channel (high read_rate_limit_ms but slow device) — confirm; rate-limit errors will start firing.

Documentation

• Template format: https://github.com/wirenboard/wb-mqtt-serial/blob/master/docs/template.md
• RS-485: https://wiki.wirenboard.com/wiki/RS-485
• Modbus: https://wiki.wirenboard.com/wiki/Modbus
• Common registers: https://wiki.wirenboard.com/wiki/Common_Modbus_Registers
• Diagnostics guide: https://wiki.wirenboard.com/wiki/How_to_diagnose
• Modbus FC spec: https://modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf
• Examples: /usr/share/wb-mqtt-serial/templates/ on the controller (250+ templates).