> 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/hardware/card-readers/mms-dyna-devices/dynaflex-ii-go/documents/developers-manuals/programmers-manual-commands/commands/user-interface.md).

# User Interface

## Command Group 0x18nn - User Interface

The host uses this command to provide a cardholder selection to the device when the device itself does not have a display or inputs to prompt the cardholder for a selection.

Sequence of events:

{% stepper %}
{% step %}

### Transaction already started

The host has already invoked Command 0x1001 - Start Transaction  and the transaction is still in process.
{% endstep %}

{% step %}

### Device requests host UI action

During the transaction, if the device does not have a display or touchscreen but needs to show information to the cardholder or needs the cardholder to make a selection, it sends the host **Notification 0x1803 - User Interface Host Action Request** to report Display / Cardholder Selection and supporting information.
{% endstep %}

{% step %}

### Host prompts cardholder

The host uses its user interface to request a selection from the cardholder based on the information and selectable items provided by the notification message.
{% endstep %}

{% step %}

### Host reports the selection to the device

The host sends the user selection to the device by sending Command 0x1802 in the format described below.
{% endstep %}
{% endstepper %}

## Table - Request Data for Command 0x1802 - Report Cardholder Selection

Beginning of any wrappers, at minimum including **Request Message**.

<table><thead><tr><th width="74.66665649414062">Tag</th><th width="74">Len</th><th width="437.33331298828125">Value / Description</th><th width="75.66668701171875">Typ</th><th width="75.33331298828125">Req</th><th width="97.3333740234375">Default</th></tr></thead><tbody><tr><td>1802</td><td></td><td><strong>Command 0x1802 - Report Cardholder Selection</strong></td><td></td><td></td><td></td></tr><tr><td>81</td><td>01</td><td>Cardholder Selection Request Status<br>- 0x00 = Cardholder Selection Request completed, see Selection Result parameter.<br>- 0x01 = Cardholder Selection Request canceled by cardholder, Transaction Aborted.<br>- 0x02 = Cardholder Selection Request timed out, Transaction Aborted.</td><td>B</td><td>R</td><td></td></tr><tr><td>82</td><td>01</td><td>Selection Result — Menu item index the cardholder selected. If the cardholder made no selection or the operation terminated abnormally, the device does not include this parameter.</td><td>B</td><td>O</td><td></td></tr><tr><td></td><td></td><td>End of any wrappers, at minimum including <a href="https://magtek.gitbook.io/magtek-pilot-gitbooks/internal-documentation/index/3.0-messages-requests-responses-notifications-and-files/3.3-message-structure#table-11-request-message-format"><strong>Request Message</strong>.</a></td><td></td><td></td><td></td></tr></tbody></table>

If the request started successfully, the Request Status in the message wrapper is **OK, Started / Running, All good / requested operation was successful**.

## Table - Response Data for Command 0x1802 - Report Cardholder Selection

Beginning of any wrappers, at minimum including **Response Message**.

<table><thead><tr><th width="73.66665649414062">Tag</th><th width="77.3333740234375">Len</th><th>Value / Description</th><th width="75.33331298828125">Typ</th><th width="73.33331298828125">Req</th><th width="97.3333740234375">Default</th></tr></thead><tbody><tr><td>1802</td><td></td><td><strong>Command 0x1802 - Report Cardholder Selection</strong></td><td></td><td></td><td></td></tr><tr><td></td><td></td><td>No parameters.</td><td></td><td></td><td></td></tr><tr><td></td><td></td><td>End of any wrappers, at minimum including <strong>Response Message</strong>.</td><td></td><td></td><td></td></tr></tbody></table>

## Table - Request Example (Hex)

{% code title="Request (hex)" %}

```
AA 00 81 04 01 00 18 02 84 08 18 02 81 01 00 82 01 00
```

{% endcode %}

## Response Example (Hex)

{% code title="Response (hex)" %}

```
AA 00 81 04 82 00 18 02 82 04 01 00 00 00
```

{% endcode %}


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