Alerts and the bridge's health sensors

The bridge raises an alert when something needs you. Examples: a battery command the aGate refused, an aGate that stopped answering, or live data that stopped arriving. Alerts are kept in the bridge, so one that happened while nobody was looking is still there the next time you open it.

Which alerts

Alert	When	Severity
Battery command refused	The aGate rejected a command, or the bridge refused to send it. The message says which. Repeats within 10 minutes count as one.	critical
Write ignored by the aGate	The aGate accepted a mode or reserve write, but the value didn't change.	critical
aGate unreachable	It hasn't answered for 5 minutes. Clears after 2 minutes back.	critical
Live data missing	No reading has worked for over 2 minutes. Clears after 1 good minute.	critical
Some live data missing	Registers 15500–15509 (solar, home load, mode, reserves) have been missing for 2 minutes while other readings arrive.	warning
A bridge task stopped	One of the bridge's own background tasks (polling, schedules, the reachability check, log writing, alert handling) stopped running or crashed.	critical

Where you see them

• Home Assistant notifications. Every critical alert also appears in HA's notifications (the bell in HA's sidebar), even with no phone set up. When an admin acknowledges the alert in the bridge, the HA notification is removed. Dismissing it in HA does not acknowledge it in the bridge. HA notifications are on by default and can be switched off. Then critical alerts reach only the bridge.
• Your phone. With the Home Assistant Companion app, see Phone, notifications and remote access.

The bridge's own device in Home Assistant

Besides one device per aGate, the bridge publishes a device for itself, FranklinWH Modbus Bridge, with two diagnostic sensors:

Sensor	What it shows
Bridge problem	On while any alert still needs someone, for any aGate, including one that never answered. Its attributes list the open alerts (level, open, alerts). It stays readable even while an aGate or the bridge is down.
Bridge heartbeat	The time the bridge last checked in. It updates every 60 seconds. If the bridge stops or hangs, the time stops moving.

Automations to add in Home Assistant

The bridge can't tell you it has stopped: these two automations in HA can. Check the entity IDs on the bridge's device page in HA (Settings → Devices & services → MQTT → FranklinWH Modbus Bridge). The IDs below are the usual ones, and the notify service is an example: use your own phone's.

- alias: "FranklinWH bridge stopped checking in"
  triggers:
    - trigger: template
      value_template: >
        {{ now() - as_datetime(states('sensor.franklinwh_modbus_bridge_bridge_heartbeat'))
           > timedelta(minutes=5) }}
  actions:
    - action: notify.mobile_app_your_phone
      data:
        title: "FranklinWH bridge"
        message: "The bridge hasn't checked in for 5 minutes. It may have stopped."

- alias: "FranklinWH bridge problem"
  triggers:
    - trigger: state
      entity_id: binary_sensor.franklinwh_modbus_bridge_bridge_problem
      to: "on"
  actions:
    - action: notify.mobile_app_your_phone
      data:
        title: "FranklinWH bridge"
        message: "The bridge has an alert. Open it to see what to do."

A template trigger that uses now() is checked every minute, so the first automation fires within about a minute of the 5 minutes passing.