---
alias: user-guide-automation-task-opcua-writefile
tags:
- automation tasks
description: "This task writes data to a file on an OPC UA server"
---

# Write File

:iot-commandresult-lg:{style="font-size: 100px"}

This task write data to a file in OPC UA server using the File Transfer feature. To be used with OPC UA driver in Client mode.

![Screenshot showing a file writing operation with filename input field.](./images/write_file_parameters.png)

## Inputs

| Name     | Data Type | Description                                |
| -------- |  ---------| ------------------------------------------ |
| nodeId   | `String`  | The node id where the file will be written |
| rawData  | `Buffer`  | The raw data to be written in the file     |
| Activate |  `any`    | Activate the task                          |

## Outputs

| Name    | Data Type | Description                                            |
| ------  | --------- | ------------------------------------------------------ |
| Success | `Boolean` | If there was no problem emits a true                   |
| Error   | `Error`   | Error that occurred during the processing of this task |

## Settings

On the *General Tab*, you have the usual settings and the following settings:

| Name               | Data Type | Default | Description                                                                                                                                                                                |
| ------------------ | --------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Data Chunk Size    | `Number`  | 0       | If the value is 0, splitting the data buffer into chunks is disabled. Otherwise, the received buffer size will be divided by this value, creating several data chunks.                     |
| Open File Command  | `String`  | .Open   | Node command syntax to be appended to the File Object node id to identify and invoke the Open File command (for example, `.Open`, resulting in `FileNodeId.Open`). Useful to prevent break of compatibilities.    |
| Close File Command | `String`  | .Close  | Node command syntax to be appended to the File Object node id to identify and invoke the Close File command (for example, `.Close`, resulting in `FileNodeId.Close`). Useful to prevent break of compatibilities. |
| Write File Command | `String`  | .Write  | Node command syntax to be appended to the File Object node id to identify and invoke the Write File command (for example, `.Write`, resulting in `FileNodeId.Write`). Useful to prevent break of compatibilities. |

![Screenshot showing the "Write File" settings.](./images/write_file_settings.png)

## Behavior

Activate will trigger a message to the driver. The contents of the message are the values received in the inputs and settings.

## Remarks

* All the communication with the equipment is handled by the driver in the backend.
* The existing content of the file is erased and the new data will be saved.