> For the complete documentation index, see [llms.txt](https://docs.influxtechnology.com/support_guides/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.influxtechnology.com/support_guides/rexdesk-configuration-software-s/rexdesk-rexgen-series-configuration-software/rexdesk-manual/quick-start-guide/preparation-of-configuration/using-the-uds-function.md).

# Using the UDS function

Used to monitor UDS (Unified Diagnostic Service )diagnostic messages over CAN.

<figure><img src="https://109727927-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUEja6FQFpk6wbBteOsbv%2Fuploads%2FsmhJb0tjBAz4zSqGL9D2%2Fimage.png?alt=media&amp;token=c1521f77-e57b-4d76-8441-11c52561f1c6" alt=""><figcaption></figcaption></figure>

* **CAN Add:** The user can create a new event message in the CAN communication setup.
* **CAN Remove:** Allows the user to delete a selected CAN message from the event message list.
* **Move Up:** Allows the user to shift a selected message to a higher level in the list.
* **Move Down:** Allows the user to shift a selected message to a lower level in the list.
* **TX:** Specifies the transmit ID used to send messages from the tester to the ECU.
* **RX:** Specifies that the responses are expected from the ECU using this ID.
* **Delay:** Allows the user to specify the interval between messages.
* **Time out:** Allows the user to specify the delay in response before considering it a timeout.
* **Attempt:** Allows the user to specify the number of times it wants the software to repeat the process.
* **Type:** This allows the user to select the CAN communication type to send and receive data and communicate with the ECU.
* **BRS:** Allows the user to switch to a higher bitrate (faster speed) during the data phase of the transmission.
* **DLC:** Indicates the number of data bytes in the message. It can range from 0 to 8 bytes.
* **Data**

### **Single**:

This command switches the ECU into **Extended Diagnostic Session** mode, which is required before accessing many advanced features or data.

### Repeatable

This command sends a series of CAN messages repeatedly to the ECU.


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