Stop hub

The Stop hub action stops a Modbus hub and closes its connection to your hardware. Use it when you need to release the connection, for example before another application takes over the serial port or network connection.

Using this action from the user interface

If you prefer building automations and scripts visually, Home Assistant walks you through this action step by step. You pick what to target, tweak a few options, and save. No YAML knowledge required.

To use this action in an automation or script:

1. Go to Settings > Automations & scenes.
2. Open an existing automation or script, or select Create to start a new one.
3. If you’re setting up a new automation, add a trigger in the When section. Scripts don’t need a trigger.
4. In the Then do section, select Add action.
5. From the search box, search for and select Modbus: Stop hub.
6. Enter the name of the hub you want to stop.
7. Select Save.

This action does not support targets. In the UI, you are not prompted to choose an area, device, entity, or label. Instead, you select the Modbus hub by name.

Options in the UI

Using this action in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this action as modbus.stop. A basic example looks like this:

action: modbus.stop
data:
  hub: modbus_hub

This stops the hub named modbus_hub.

Options in YAML

Good to know

• To start the hub again, use the Reload action.

Try it yourself

Ready to test this? Open Developer tools > Actions, search for this action, fill in the fields, and select Perform action. You see what happens on your actual entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] without writing a line of YAML.

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the action you’re calling and what you expected to happen, or share on our subreddit /r/homeassistant.

Related actions

These actions work well alongside this one:

• Reload Modbus configuration: Reloads the Modbus configuration from your YAML configuration.

• Write register: Writes a value to one or more Modbus holding registers.

• Write coil: Writes a state to one or more Modbus coils.