RPC Call Request

Use this node to send a Remote Procedure Call (RPC) from the server to a device and receive its response as the outgoing message — for example, reading a sensor value on demand, toggling a GPIO pin, or triggering a firmware check on a device that is currently connected.

Configuration

Timeout in seconds — required. Maximum time to wait for the device response before failing. Default: 60. Used when no explicit expiration time is present in the message metadata.

Message processing

The message data must contain two required fields:

method — the RPC method name to call on the device.
params — the parameters to pass to the method (any JSON value).

Optional fields can be provided in the message metadata:

Key	Type	Description
`oneway`	boolean	If `true`, no response is expected (fire-and-forget). Default: `false`.
`persistent`	boolean	If `true`, the request is persisted. Default: `false`.
`requestUUID`	string	Unique request identifier for tracking. Auto-generated if absent.
`originServiceId`	string	Originating service for routing the response.
`expirationTime`	long	Expiration timestamp (ms). Calculated from timeout if absent.
`retries`	integer	Number of retry attempts.

Optional fields in message data:

Key	Type	Description
`requestId`	integer	Request identifier for matching the response. Random if absent.
`additionalInfo`	JSON	Extra metadata attached to the request.

Message processing algorithm

Validate that the originator is a DEVICE. If not, route via Failure.
Validate that message data contains method and params. If either is missing, route via Failure.
Collect optional parameters from message data and metadata and build the RPC request.
Send the RPC to the device and acknowledge the original message immediately.
On device response:
- Success: replace message data with the device response; route via Success.
- Failure: route via Failure with an error description.

Output connections

Connection	Condition
`Success`	Device responded successfully. Outgoing message data contains the device response.
`Failure`	Originator is not a `DEVICE`, missing `method` or `params`, device timeout, or device returned an error.

Examples

Example 1 — Two-way RPC: set GPIO pin

Originator: DEVICE.

{
  "method": "setGpio",
  "params": {
    "pin": 7,
    "value": 1
  }
}

{
  "timeoutInSeconds": 30
}

Response from device (outgoing message data):

{
  "success": true
}

Routes via Success.

Example 2 — One-way RPC: reboot device

Metadata: { "oneway": "true" } | Data: { "method": "reboot", "params": {} } | Config: { "timeoutInSeconds": 60 }.

Outgoing message data: {} (no response expected). Routes via Success.

JSON schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "TbSendRpcRequestNodeConfiguration",
  "type": "object",
  "required": ["timeoutInSeconds"],
  "additionalProperties": false,
  "properties": {
    "timeoutInSeconds": {
      "type": "integer",
      "description": "Maximum time to wait for device response in seconds."
    }
  }
}