> 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/dynaprox/documents/programmers-manuals/programmers-manual-commands/commands/user-interface/card-emulation.md).

# Card Emulation

## Command 0x1840 – Card Emulation

Card emulation is initiated by receiving a 0x1840 command from the host. The device will prepare card emulation with the parameters provided in the command and start card emulation.

The sequence of events is as follows:

{% stepper %}
{% step %}

### Host ensures device is idle

The host ensures the device is not currently running another command, for example, that it is not running a transaction or PIN entry.
{% endstep %}

{% step %}

### Host composes and sends command

The host composes a command request in the format described below and sends it to the device.
{% endstep %}

{% step %}

### Device validates and prepares

The device receives the command and verifies that the parameters are valid and the device is in a state that allows the execution of card emulation.
{% endstep %}

{% step %}

### Device prompts customer (if display available)

If the device has a display, a prompt will be displayed asking the customer to tap their phone to the device.
{% endstep %}

{% step %}

### Timeout behavior and response

* If the timeout parameter is not included or set to 0x00, then there is no timeout.
* If the timeout parameter is set to a specific number of seconds, the device returns a command response message with its Operation Status Summary byte set to 0x01 (OK, Started / Running).
  {% endstep %}

{% step %}

### Host can cancel emulation

The host may issue a 0x1840 command with Tag 0x81 set to 0x00 to cancel the execution of card emulation.
{% endstep %}

{% step %}

### Completion notification

After the timeout expires, host cancel or the card is read, the device sends a 0x1805 notification to inform the host.
{% endstep %}
{% endstepper %}

## Table - Request Data for Command 0x1840 – Card Emulation

<table><thead><tr><th width="72.33334350585938">Tag</th><th width="81.3333740234375">Len</th><th>Value / Description</th><th width="76">Req</th><th width="98.6666259765625">Default</th></tr></thead><tbody><tr><td>/81</td><td>01</td><td><p>Start/Cancel</p><ul><li>0x00 = Cancel (See the example of 0x1840 cancel command below)</li><li>0x01 = Start</li></ul></td><td>R</td><td></td></tr><tr><td>/82</td><td>01</td><td><p>Timeout in seconds</p><ul><li>0x00 = No timeout</li><li>0x01 to 0xFF = 1 to 255 seconds</li></ul></td><td>O</td><td>0x00</td></tr><tr><td>/83</td><td>&#x3C;= 254</td><td><p>URL </p><p>URL to use as card data. Required when starting card emulation. Optional and ignored if canceling emulation. Example: https://www.magtek.com/</p></td><td>O/R</td><td></td></tr></tbody></table>

## Table - Request Example

{% code title="Example (Hex)" %}

```
AA 00 81 04 01 01 18 40 84 21 18 40 81 01 01 82 01 00 83 17 68 74 74 70 73 3A 2F 2F 77 77 77
2E 6D 61 67 74 65 6B 2E 63 6F 6D 2F

```

{% endcode %}

## Table - Response Example

{% code title="Example (Hex)" %}

```
AA 00 81 04 82 01 18 40 82 04 01 00 00 00
```

{% endcode %}

## Table- Example of 0x1840 Card Emulation Command

{% code title="Example (Hex)" %}

```
AA 00 81 04 01 01 18 40 84 05 18 40 81 01 00
```

{% endcode %}


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