In development: Sending commands and shared-attribute changes from Hermetry to child devices through their gateway is not available yet. Do not plan a deployment that depends on it.
What this covers
A child device is a field device that a gateway reports for (see Devices behind a gateway). The feature in development lets you:
- send a command to a child (for example, switch a relay output of a field device) from the device page, a dashboard control, a Rules card or a flow, and
- change a child’s shared attributes and have the gateway apply them to the field device.
Until it is released, treat child devices as read only from the cloud.
What works today
| Need | Today |
|---|---|
| Read values from field devices | Works: the gateway reports them as child devices. |
| Send a command to the gateway itself | Works, like any device. See Sending commands to devices. |
| Change settings of a licensed gateway | Works through its remote settings. See Remote device settings. |
| Change a value on a field device | Not from Hermetry yet. Change it locally, on the gateway’s own panel or on the field device. A licensed router’s panel can be opened from Hermetry; see Remote access to a router’s panel. |
What you may see
The MQTT topic reference lists the gateway downlink topics (v1/gw/rpc, the downlink v1/gw/attributes and v1/gw/attributes/res) and the attribute request topic v1/gw/attributes/req. They belong to this feature. Do not build gateway software that depends on them until this page says the feature is available.