> For the complete documentation index, see [llms.txt](https://developer.magtek.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.magtek.com/products/dynafamily-mms-dyna-devices/dynaflex-ii-ped/programmers-manual/message-format-and-structure.md).

# Message Format & Structure

Every exchange with the DynaFlex II PED — the commands you send and the responses and notifications it returns — uses the standard Multi-Interface Card Reader Platform (MMS) message format. This section defines how requests, responses, notifications, and file messages are framed and parsed. The format is the same across Dyna-family readers and is documented once in the shared reference.

{% hint style="success" %}
**Applies to:** DynaFlex II PED
{% endhint %}

### Settings & Information - Group 0xD1nn

| **Reference Section**                                                                                                                                                                             | **Information Available**                                                                                                                                                                                                                            |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [<mark style="color:red;">**About Messages**</mark>](https://developer.magtek.com/api-and-command-reference/scra-dynafamily-programmers-manual/message-format-and-structure/about-messages)       | The host and the device communicate with each other by exchanging blocks of data called Messages, which are standardized wrappers containing a payload that is either a command Request, a command Response, an unsolicited Notification, or a File. |
| [<mark style="color:red;">**Message Format**</mark>](https://developer.magtek.com/api-and-command-reference/scra-dynafamily-programmers-manual/message-format-and-structure/message-format)       | All messages exchanged between the host and the device are formatted using the tag-length-value Distinguished Encoding Rules (DER).                                                                                                                  |
| [<mark style="color:red;">**Message Structure**</mark>](https://developer.magtek.com/api-and-command-reference/scra-dynafamily-programmers-manual/message-format-and-structure/message-structure) | Each message type follows a specific structure described on this page.                                                                                                                                                                               |

{% hint style="info" %}
**Need Help?**

For additional support, please contact MagTek Support:

**Technical Support:**

* 📧 **Email:** [support@magtek.com](mailto:support@magtek.com?subject=Support%20Request)
* 📞 **Phone:** 1-562-546-6800 (US)
* 🕐 **Hours:** Monday-Friday, 5:30 AM - 5:00 PM PST

**Online Resources:**

* 🌐 **Support Portal:** developer.magtek.com

**Documentation Feedback:**

Help us improve this documentation! [feedback@magtek.com](mailto:feedback@magtek.com?subject=Feedback)
{% endhint %}


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