Tau.Acuvim/docs/mqtt-protocol.md

MQTT Protocol Reference

Complete reference for the MQTT topic structure, payload formats, command/response protocol, and quality-of-service settings used between ESP32 devices and the console application.

---

1. Topic Structure

All topics use the following prefix convention:

{prefix}/{device_id}/{message_type}

• prefix: Configurable, default acuvim
• device_id: Unique device identifier, format ACV-AABBCCDDEEFF (derived from MAC address)
• message_type: One of the types listed below

Topic Map

Topic	Direction	QoS	Retain	Description
acuvim/{device_id}/telemetry	Device -> Broker	0	No	Acuvim II power meter readings
acuvim/{device_id}/heartbeat	Device -> Broker	1	No	Device health and status
acuvim/{device_id}/cmd	Console -> Device	1	No	Commands to the device
acuvim/{device_id}/resp	Device -> Console	1	No	Command responses
acuvim/{device_id}/status	Device / Broker (LWT)	1	Yes	Online/offline status
acuvim/{device_id}/alerts	Device -> Broker	1	No	Threshold violation alerts
devices/register	Device -> Broker	1	No	Device self-registration

Wildcard Subscriptions (Console)

The console application subscribes to the following wildcard topics to receive messages from all devices:

acuvim/+/telemetry
acuvim/+/heartbeat
acuvim/+/resp
acuvim/+/status
acuvim/+/alerts
devices/register

---

2. Telemetry

Topic

acuvim/{device_id}/telemetry

QoS and Delivery

• QoS 0 (at most once): Telemetry is high-frequency data. Occasional message loss is acceptable. Using QoS 0 reduces overhead, especially over GSM.
• Retain: No
• Publish interval: Configurable via poll_interval_sec, default 5 seconds on WiFi, 30 seconds on GSM.

Payload Format

{
  "ts": 1716000000,
  "dev": "ACV-AABBCCDDEEFF",
  "v": {
    "a": 230.1,
    "b": 231.4,
    "c": 229.8,
    "ab": 399.2,
    "bc": 400.1,
    "ca": 398.7
  },
  "i": {
    "a": 15.2,
    "b": 14.8,
    "c": 15.5
  },
  "p": {
    "total": 10.5,
    "a": 3.5,
    "b": 3.4,
    "c": 3.6,
    "reactive": 2.1,
    "apparent": 10.7,
    "pf": 0.98
  },
  "f": 50.01,
  "e": {
    "imp_act": 12345.6,
    "exp_act": 0.0,
    "imp_react": 1234.5,
    "exp_react": 0.0
  },
  "d": {
    "act": 10.2,
    "max_act": 15.0,
    "react": 2.0
  },
  "thd": {
    "va": 2.1,
    "vb": 2.3,
    "vc": 2.0,
    "ia": 5.4,
    "ib": 5.1,
    "ic": 5.6
  },
  "conn": "wifi",
  "rssi": -45,
  "src": "live"
}

Field Reference

Field Path	Type	Unit	Description
ts	integer	epoch seconds (UTC)	Timestamp of the reading
dev	string	-	Device ID
v.a	float	V	Phase A voltage (L-N)
v.b	float	V	Phase B voltage (L-N)
v.c	float	V	Phase C voltage (L-N)
v.ab	float	V	Line voltage A-B
v.bc	float	V	Line voltage B-C
v.ca	float	V	Line voltage C-A
i.a	float	A	Phase A current
i.b	float	A	Phase B current
i.c	float	A	Phase C current
p.total	float	kW	Total active power
p.a	float	kW	Phase A active power
p.b	float	kW	Phase B active power
p.c	float	kW	Phase C active power
p.reactive	float	kVAR	Total reactive power
p.apparent	float	kVA	Total apparent power
p.pf	float	-	Total power factor (-1.0 to 1.0)
f	float	Hz	Line frequency
e.imp_act	float	kWh	Import active energy (accumulated)
e.exp_act	float	kWh	Export active energy (accumulated)
e.imp_react	float	kVARh	Import reactive energy (accumulated)
e.exp_react	float	kVARh	Export reactive energy (accumulated)
d.act	float	kW	Active power demand
d.max_act	float	kW	Maximum active power demand
d.react	float	kVAR	Reactive power demand
thd.va	float	%	Voltage THD Phase A
thd.vb	float	%	Voltage THD Phase B
thd.vc	float	%	Voltage THD Phase C
thd.ia	float	%	Current THD Phase A
thd.ib	float	%	Current THD Phase B
thd.ic	float	%	Current THD Phase C
conn	string	-	Active transport: "wifi" or "gsm"
rssi	integer	dBm	Signal strength (WiFi RSSI or GSM equivalent)
src	string	-	Data source: "live" (real-time) or "sd" (buffered from SD card)

Notes

• All floating-point values are IEEE 754 single-precision, read from Modbus as big-endian 32-bit floats across two consecutive registers.
• Short JSON keys are used to minimize payload size, which is important when transmitting over GSM.
• The thd group may be omitted when transmitting over GSM to reduce payload size.
• When replaying buffered data from the SD card, src is set to "sd" and the ts reflects the original measurement time.

---

3. Heartbeat

Topic

acuvim/{device_id}/heartbeat

QoS and Delivery

• QoS 1 (at least once): Heartbeats are critical for device health monitoring. Guaranteed delivery ensures the console can accurately track device status.
• Retain: No
• Publish interval: Configurable via heartbeat_interval_sec, default 60 seconds.
• Sent immediately on boot, on transport switch, and on demand via the set_heartbeat command.

Payload Format

{
  "ts": 1716000000,
  "dev": "ACV-AABBCCDDEEFF",
  "fw": "1.2.0",
  "up": 86400,
  "boot": 3,
  "hb": 1440,
  "conn": {
    "type": "wifi",
    "wifi": {
      "ssid": "SiteNetwork",
      "rssi": -45,
      "ip": "192.168.1.100"
    },
    "gsm": {
      "enabled": true,
      "connected": false,
      "signal": 0,
      "operator": ""
    },
    "mqtt": true
  },
  "health": {
    "heap_free": 120000,
    "heap_min": 95000,
    "psram_free": 3800000,
    "cpu_temp": 52.3,
    "reset_reason": "POWER_ON",
    "uptime_sec": 86400
  },
  "modbus": {
    "connected": true,
    "success": 17280,
    "errors": 12,
    "error_rate": 0.07,
    "last_error": 0,
    "last_read_ms": 45
  },
  "sd": {
    "available": true,
    "queued": 0,
    "free_mb": 3800
  },
  "ota": {
    "version": "1.2.0",
    "partition": "app0",
    "update_available": false
  }
}

Field Reference

Field Path	Type	Description
ts	integer	UTC epoch timestamp
dev	string	Device ID
fw	string	Current firmware version (semver)
up	integer	Uptime in seconds since last boot
boot	integer	Total boot count (persisted in NVS, increments each restart)
hb	integer	Heartbeat sequence number since last boot
conn.type	string	Active transport: "wifi" or "gsm"
conn.wifi.ssid	string	Connected WiFi SSID
conn.wifi.rssi	integer	WiFi signal strength in dBm
conn.wifi.ip	string	Assigned IP address
conn.gsm.enabled	boolean	Whether GSM is enabled in config
conn.gsm.connected	boolean	Whether GSM is currently connected
conn.gsm.signal	integer	GSM signal quality (0-31 CSQ scale)
conn.gsm.operator	string	Mobile network operator name
conn.mqtt	boolean	Whether MQTT is currently connected
health.heap_free	integer	Current free heap memory in bytes
health.heap_min	integer	Minimum free heap since boot (leak detection)
health.psram_free	integer	Free PSRAM in bytes
health.cpu_temp	float	ESP32 internal temperature in Celsius
health.reset_reason	string	Last reset reason (see table below)
health.uptime_sec	integer	Uptime in seconds
modbus.connected	boolean	Whether last Modbus read succeeded
modbus.success	integer	Total successful Modbus reads since boot
modbus.errors	integer	Total failed Modbus reads since boot
modbus.error_rate	float	Error percentage (errors / total * 100)
modbus.last_error	integer	Last Modbus error code (0 = none)
modbus.last_read_ms	integer	Duration of last complete read cycle in ms
sd.available	boolean	Whether an SD card is detected
sd.queued	integer	Number of buffered telemetry records awaiting drain
sd.free_mb	integer	Free space on SD card in megabytes
ota.version	string	Currently running firmware version
ota.partition	string	Active OTA partition ("app0" or "app1")
ota.update_available	boolean	Whether a newer firmware version is available

Reset Reason Values

Value	Meaning
POWER_ON	Normal power-on reset
EXTERNAL	External reset pin
SW_RESET	Software restart (e.g., ESP.restart())
PANIC	Guru Meditation / exception handler
INT_WDT	Interrupt watchdog timeout
TASK_WDT	Task watchdog timeout
WDT	Other watchdog timeout
DEEP_SLEEP	Wake from deep sleep
BROWNOUT	Brownout reset (low voltage)
UNKNOWN	Unrecognized reset reason

Console Health Detection

The console uses heartbeat timing to determine device status:

Condition	Status
Heartbeat received within 1x interval	Online
No heartbeat for 3x interval	Degraded
No heartbeat for 5x interval	Offline

---

4. Command / Response Protocol

Command (Console to Device)

Topic: acuvim/{device_id}/cmd QoS: 1 Retain: No

{
  "cmd": "<command_name>",
  "request_id": "<unique_identifier>",
  "params": { }
}

• cmd: The command name (see complete list below).
• request_id: A unique string generated by the console to correlate the response. Format is typically a UUID or short identifier like "cmd-a1b2c3".
• params: Command-specific parameters. Omit or pass {} for commands with no parameters.

Response (Device to Console)

Topic: acuvim/{device_id}/resp QoS: 1 Retain: No

{
  "request_id": "<matching_identifier>",
  "status": "success",
  "data": { },
  "message": "Human-readable description"
}

• request_id: Must match the request_id from the originating command.
• status: Either "success" or "error".
• data: Command-specific response data. May be omitted for simple acknowledgements.
• message: Human-readable status message.

Command Timeout

If the console does not receive a response within 60 seconds, the command is marked as "timeout". The device should respond as quickly as possible; most commands respond in under 2 seconds.

---

5. Complete Command Reference

5.1 ping

Connectivity test. The device responds with a pong.

Request:

{
  "cmd": "ping",
  "request_id": "ping-001"
}

Response:

{
  "request_id": "ping-001",
  "status": "success",
  "data": { "pong": true },
  "message": "pong"
}

---

5.2 get_config

Returns the full device configuration (passwords are masked).

Request:

{
  "cmd": "get_config",
  "request_id": "cfg-001"
}

Response:

{
  "request_id": "cfg-001",
  "status": "success",
  "data": {
    "device_id": "ACV-AABBCCDDEEFF",
    "wifi": {
      "ssid": "SiteNetwork",
      "enabled": true
    },
    "mqtt": {
      "broker": "console.example.com",
      "port": 8883,
      "tls": true,
      "topic_prefix": "acuvim"
    },
    "gsm": {
      "apn": "internet",
      "enabled": true
    },
    "modbus": {
      "slave_addr": 1,
      "baud_rate": 9600,
      "poll_interval": 5
    },
    "heartbeat_interval": 60,
    "console_url": "https://console.example.com",
    "firmware_version": "1.2.0"
  }
}

---

5.3 get_status

Returns the current device status including health metrics.

Request:

{
  "cmd": "get_status",
  "request_id": "stat-001"
}

Response:

{
  "request_id": "stat-001",
  "status": "success",
  "data": {
    "uptime": 86400,
    "heap_free": 120000,
    "heap_min": 95000,
    "wifi_connected": true,
    "wifi_rssi": -45,
    "gsm_connected": false,
    "mqtt_connected": true,
    "modbus_connected": true,
    "modbus_errors": 12,
    "sd_available": true,
    "sd_queued": 0,
    "boot_count": 3,
    "reset_reason": "POWER_ON"
  }
}

---

5.4 get_telemetry

Returns the most recent Acuvim II reading.

Request:

{
  "cmd": "get_telemetry",
  "request_id": "tel-001"
}

Response:

{
  "request_id": "tel-001",
  "status": "success",
  "data": {
    "ts": 1716000000,
    "v": { "a": 230.1, "b": 231.4, "c": 229.8 },
    "i": { "a": 15.2, "b": 14.8, "c": 15.5 },
    "p": { "total": 10.5, "pf": 0.98 },
    "f": 50.01
  }
}

---

5.5 restart

Restarts the ESP32. The device publishes the response before restarting.

Request:

{
  "cmd": "restart",
  "request_id": "rst-001"
}

Response:

{
  "request_id": "rst-001",
  "status": "success",
  "message": "Restarting in 2 seconds"
}

---

5.6 factory_reset

Clears all NVS configuration and restarts the device into AP mode. Requires explicit confirmation.

Request:

{
  "cmd": "factory_reset",
  "request_id": "fr-001",
  "params": {
    "confirm": true
  }
}

Response:

{
  "request_id": "fr-001",
  "status": "success",
  "message": "Factory reset complete, restarting into AP mode"
}

If confirm is missing or false:

{
  "request_id": "fr-001",
  "status": "error",
  "message": "Factory reset requires params.confirm = true"
}

---

5.7 wifi_scan

Scans for available WiFi networks and returns the results.

Request:

{
  "cmd": "wifi_scan",
  "request_id": "scan-001"
}

Response:

{
  "request_id": "scan-001",
  "status": "success",
  "data": {
    "networks": [
      { "ssid": "SiteNetwork", "rssi": -40, "enc": "WPA2", "ch": 6 },
      { "ssid": "GuestWifi", "rssi": -65, "enc": "WPA2", "ch": 11 },
      { "ssid": "OpenNet", "rssi": -78, "enc": "OPEN", "ch": 1 }
    ]
  }
}

---

5.8 wifi_set

Updates WiFi credentials. The device will disconnect from the current network and connect to the new one.

Request:

{
  "cmd": "wifi_set",
  "request_id": "wset-001",
  "params": {
    "ssid": "NewNetwork",
    "password": "newpassword123"
  }
}

Response:

{
  "request_id": "wset-001",
  "status": "success",
  "message": "WiFi credentials updated, reconnecting"
}

---

5.9 wifi_disconnect

Disconnects from the current WiFi network without clearing credentials.

Request:

{
  "cmd": "wifi_disconnect",
  "request_id": "wdisc-001"
}

Response:

{
  "request_id": "wdisc-001",
  "status": "success",
  "message": "WiFi disconnected"
}

---

5.10 mqtt_set

Updates the MQTT broker configuration. The device will disconnect and reconnect with the new settings.

Request:

{
  "cmd": "mqtt_set",
  "request_id": "mset-001",
  "params": {
    "broker": "mqtt.newserver.com",
    "port": 8883,
    "username": "ACV-AABBCCDDEEFF",
    "password": "newpassword",
    "topic_prefix": "acuvim",
    "tls": true
  }
}

Response:

{
  "request_id": "mset-001",
  "status": "success",
  "message": "MQTT configuration updated, reconnecting"
}

Warning: This command can render the device unreachable via MQTT if incorrect values are provided. Ensure fallback access via the captive portal.

---

5.11 gsm_set

Updates GSM/cellular configuration.

Request:

{
  "cmd": "gsm_set",
  "request_id": "gset-001",
  "params": {
    "apn": "internet",
    "username": "",
    "password": "",
    "enabled": true
  }
}

Response:

{
  "request_id": "gset-001",
  "status": "success",
  "message": "GSM configuration updated"
}

---

5.12 transport_priority

Sets the transport priority order for network failover.

Request:

{
  "cmd": "transport_priority",
  "request_id": "tp-001",
  "params": {
    "priority": "wifi_first"
  }
}

Valid values for priority:

Value	Behaviour
wifi_first	Prefer WiFi, fall back to GSM (default)
gsm_first	Prefer GSM, fall back to WiFi
wifi_only	WiFi only, no GSM fallback
gsm_only	GSM only, no WiFi

Response:

{
  "request_id": "tp-001",
  "status": "success",
  "message": "Transport priority set to wifi_first"
}

---

5.13 sleep_set

Configures deep sleep mode.

Request:

{
  "cmd": "sleep_set",
  "request_id": "slp-001",
  "params": {
    "enabled": true,
    "sleep_min": 15,
    "wake_sec": 60
  }
}

• sleep_min: Duration of deep sleep in minutes.
• wake_sec: Duration the device stays awake to transmit data.

Response:

{
  "request_id": "slp-001",
  "status": "success",
  "message": "Sleep mode configured: 15min sleep, 60s wake"
}

---

5.14 modbus_set

Updates Modbus RS485 communication parameters.

Request:

{
  "cmd": "modbus_set",
  "request_id": "mb-001",
  "params": {
    "slave_addr": 1,
    "baud_rate": 9600,
    "poll_interval": 5
  }
}

Response:

{
  "request_id": "mb-001",
  "status": "success",
  "message": "Modbus configuration updated"
}

---

5.15 console_set

Sets the console application URL used for OTA firmware downloads.

Request:

{
  "cmd": "console_set",
  "request_id": "curl-001",
  "params": {
    "url": "https://console.example.com"
  }
}

Response:

{
  "request_id": "curl-001",
  "status": "success",
  "message": "Console URL updated"
}

---

5.16 ota_update

Triggers an OTA firmware update. The device will download the binary from the specified URL, verify the checksum, and install it.

Request:

{
  "cmd": "ota_update",
  "request_id": "ota-001",
  "params": {
    "url": "https://console.example.com/api/firmware/download/1.3.0",
    "version": "1.3.0",
    "checksum": "a1b2c3d4e5f6..."
  }
}

Response (immediate acknowledgement):

{
  "request_id": "ota-001",
  "status": "success",
  "message": "OTA update started, downloading 1.3.0"
}

The device will reboot after successful installation. The console should monitor for the device to come back online with the new firmware version in its next heartbeat.

---

5.17 ota_check

Checks with the console whether a firmware update is available.

Request:

{
  "cmd": "ota_check",
  "request_id": "ochk-001"
}

Response:

{
  "request_id": "ochk-001",
  "status": "success",
  "data": {
    "update_available": true,
    "current_version": "1.2.0",
    "available_version": "1.3.0",
    "url": "https://console.example.com/api/firmware/download/1.3.0",
    "size": 1048576,
    "checksum": "a1b2c3d4e5f6...",
    "mandatory": false
  }
}

---

5.18 set_heartbeat

Changes the heartbeat reporting interval.

Request:

{
  "cmd": "set_heartbeat",
  "request_id": "hb-001",
  "params": {
    "interval_sec": 30
  }
}

Response:

{
  "request_id": "hb-001",
  "status": "success",
  "message": "Heartbeat interval set to 30 seconds"
}

---

5.19 set_alerts

Configures alert thresholds for the Acuvim II health monitoring.

Request:

{
  "cmd": "set_alerts",
  "request_id": "alt-001",
  "params": {
    "thresholds": {
      "overvoltage": 260.0,
      "undervoltage": 200.0,
      "overcurrent_factor": 1.2,
      "voltage_imbalance_pct": 10.0,
      "current_imbalance_pct": 20.0,
      "frequency_low": 49.5,
      "frequency_high": 50.5,
      "low_power_factor": 0.85,
      "high_thd": 8.0
    }
  }
}

Response:

{
  "request_id": "alt-001",
  "status": "success",
  "message": "Alert thresholds updated"
}

---

5.20 register_ack

Sent by the console to acknowledge a device registration. This is the only command initiated by the console without a prior user action.

Request (Console to Device):

{
  "cmd": "register_ack",
  "request_id": "reg-001",
  "params": {
    "status": "accepted",
    "device_name": "Building A - Main Incomer"
  }
}

The device saves the acknowledgement to NVS and uses device_name for display in the captive portal.

---

6. Alert Payload

Topic

acuvim/{device_id}/alerts

QoS and Delivery

• QoS 1: Alerts represent important events that should not be lost.
• Retain: No

Payload Format

{
  "ts": 1716000000,
  "dev": "ACV-AABBCCDDEEFF",
  "alert": "overvoltage",
  "severity": "warning",
  "message": "Phase A voltage 265.3V exceeds 260V threshold",
  "phase": "A",
  "value": 265.3,
  "threshold": 260.0
}

Field Reference

Field	Type	Description
ts	integer	UTC epoch timestamp
dev	string	Device ID
alert	string	Alert type identifier (see table below)
severity	string	"info", "warning", or "critical"
message	string	Human-readable description
phase	string	Affected phase ("A", "B", "C", or null for non-phase-specific alerts)
value	float	Measured value that triggered the alert
threshold	float	Configured threshold that was exceeded

Alert Types

Alert Type	Default Threshold	Severity	Description
overvoltage	> 260 V	warning	Phase voltage exceeds upper limit
undervoltage	< 200 V	warning	Phase voltage below lower limit
overcurrent	> CT rated x 1.2	warning	Phase current exceeds rated capacity
voltage_imbalance	> 10% difference	info	Excessive voltage imbalance between phases
current_imbalance	> 20% difference	info	Excessive current imbalance between phases
frequency_deviation	< 49.5 or > 50.5 Hz	warning	Frequency outside normal range
low_power_factor	< 0.85	info	Poor power factor
high_thd	> 8%	info	High total harmonic distortion
modbus_loss	5 consecutive errors	critical	Lost communication with Acuvim II
modbus_high_error_rate	> 5% over 1 hour	warning	Elevated Modbus error rate

Alert Deduplication

The device does not re-publish the same alert while the condition persists. An alert is considered cleared when the value returns within the threshold minus a hysteresis margin (e.g., overvoltage triggers at 260V, clears at 255V). After clearing, the alert can trigger again if the condition reoccurs.

---

7. Device Registration

Topic

devices/register

QoS and Delivery

• QoS 1: Registration must be reliably delivered.
• Retain: No

Payload Format

{
  "device_id": "ACV-AABBCCDDEEFF",
  "mac": "AA:BB:CC:DD:EE:FF",
  "firmware": "1.2.0",
  "hardware": "TTGO T-Call v1.4",
  "chip": "ESP32-WROVER-B",
  "imei": "123456789012345",
  "capabilities": ["wifi", "gsm", "sd", "modbus", "ota"],
  "ts": 1716000000
}

Field Reference

Field	Type	Description
device_id	string	Unique device ID derived from MAC address
mac	string	WiFi MAC address
firmware	string	Current firmware version
hardware	string	Board/hardware identification
chip	string	ESP32 chip model
imei	string	GSM modem IMEI (empty string if no GSM module)
capabilities	array	List of available features, dynamically detected at boot
ts	integer	UTC epoch timestamp

Capabilities

Capability	Meaning
wifi	WiFi radio available (always present)
gsm	GSM modem detected and operational
sd	SD card detected and mounted
modbus	Modbus RS485 interface available (always present)
ota	OTA update support (always present)

Registration Triggers

The device publishes a registration message:

1. On first boot (no registration acknowledgement stored in NVS).
2. After a factory reset (NVS cleared).
3. After a firmware update (re-register with new version).
4. Every 24 hours (periodic re-registration to confirm presence).

---

8. Last Will and Testament (LWT)

Topic

acuvim/{device_id}/status

QoS, Retain, and Behaviour

• QoS 1
• Retain: Yes (so new subscribers immediately know the device state)

The LWT is configured at MQTT connect time. If the device disconnects unexpectedly (network loss, crash, power failure), the broker publishes the LWT message on the device's behalf.

LWT Payload (Published by Broker on Unexpected Disconnect)

{
  "status": "offline",
  "timestamp": 0
}

The timestamp in the LWT is set to 0 because the broker publishes it and does not know the actual time. The console uses the message receipt time instead.

Online Payload (Published by Device on Connect)

Immediately after connecting, the device publishes to the same topic:

{
  "status": "online",
  "timestamp": 1716000000,
  "ip": "192.168.1.100",
  "fw": "1.2.0"
}

This overwrites the retained LWT message, so any new subscriber will see the device as online.

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9. QoS Summary

Message Type	QoS	Rationale
Telemetry	0	High-frequency, loss tolerable, reduces broker and network overhead
Heartbeat	1	Critical for status tracking, must be reliably delivered
Command (cmd)	1	Must reach the device to trigger actions
Response (resp)	1	Console needs to confirm command execution
Status (LWT)	1	Online/offline state must be reliably propagated
Alerts	1	Important events that should not be missed
Registration	1	Device must be registered in the console

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10. MQTT Client Configuration

Device (ESP32)

Parameter	Value
Client ID	Device ID (e.g., ACV-AABBCCDDEEFF)
Keep Alive	60 seconds
Clean Session	false (broker retains subscriptions across reconnects)
Max Payload Size	1024 bytes (PubSubClient default, increase if needed)
Reconnect Backoff	10s, 20s, 40s, 60s (max)

Console (.NET)

Parameter	Value
Client ID	acuvim-console
Keep Alive	60 seconds
Clean Session	false
Protocol	MQTT v5 (via MQTTnet)
Auto Reconnect	Yes

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11. Topic Examples

For a device with ID ACV-A1B2C3D4E5F6:

acuvim/ACV-A1B2C3D4E5F6/telemetry     <- Device publishes meter readings
acuvim/ACV-A1B2C3D4E5F6/heartbeat     <- Device publishes health data
acuvim/ACV-A1B2C3D4E5F6/cmd           <- Console publishes commands
acuvim/ACV-A1B2C3D4E5F6/resp          <- Device publishes command responses
acuvim/ACV-A1B2C3D4E5F6/status        <- Online/offline (LWT)
acuvim/ACV-A1B2C3D4E5F6/alerts        <- Device publishes threshold alerts
devices/register                       <- Device publishes registration