> 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/~/revisions/aurjDoOhAcnQLHeoR1ks/card-readers/mms-dyna-devices/emv-common-kernel/dynaflex-ii-go/documents/developers-manuals/programmers-manual-commands/commands/generic-pass-through/start-top-polling.md).

# Start/Top Polling

## Command 0x3002 – Start/Top Polling

After entering the Pass-Through Mode, the host use this command to request the device to start polling for a Type A and Type B PICC until it detects a PICC or times out.  This command automatically turns on the RF Antenna.

After NFC Type A card is detected, the device will stop the polling, activate the card and 

* Send a notification that identifies the ISO 14443 Type A (Supports ISO 14443-4 protocol).  See Notification 0x0301 – Pass-Through Mode Information Update.
* Send another notification with the UID as a payload.

After NFC Type B card is detected, the device will stop the polling, activate the card and

* Send a notification that identifies the ISO 14443 Type B (Supports ISO 144443-4 Protocol).  See Notification 0x0301 – Pass-Through Mode Information Update
* Send another notification with the UID as a payload.

If the card is not supported, the device will send error notification, and stop the polling.

## Table ‎- Request Data for Command 0x3002 – Start/Top Polling

<table data-header-hidden><thead><tr><th></th><th width="54.33331298828125"></th><th></th><th width="62"></th><th width="56.666748046875"></th><th width="80.99993896484375"></th></tr></thead><tbody><tr><td>Tag</td><td>Len</td><td>Value / Description</td><td> Typ</td><td>Req</td><td>Default</td></tr><tr><td>Beginning of any wrappers, at minimum including <strong>Request Message</strong> </td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>3002 = Command 0x3002 – Start/Top Polling</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>81</td><td>01</td><td><p>This parameter defines how long the device to poll for the PICC</p><p>·       0x00 = No timeout</p><p>·       0x01 to 0xFF = 1 to 255 seconds</p></td><td> </td><td>R</td><td></td></tr><tr><td>82</td><td>01</td><td><p>Polling Mode</p><p>·       0x00 = Stop Polling Mode.  This mode can only be used when the device is in polling state.</p><p>·       0x01 = Start Polling Mode</p></td><td> B</td><td>R</td><td></td></tr><tr><td>End of any wrappers, at minimum including <strong>Request Message</strong> </td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table>

## Table Response Data for Command 0x3002 – Start/Top Polling <a href="#ref222757634" id="ref222757634"></a>

<table data-header-hidden><thead><tr><th></th><th width="60.272705078125"></th><th width="115.27276611328125"></th><th width="56.18182373046875"></th><th width="69.81829833984375"></th><th width="80.72711181640625"></th></tr></thead><tbody><tr><td>Tag</td><td>Len</td><td>Value / Description</td><td>Typ</td><td>Req</td><td>Default</td></tr><tr><td>Beginning of any wrappers, at minimum including Response Message</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>No parameters.</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>End of any wrappers, at minimum including Response Message</td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table>

## Table Request Example

| Example (Hex)                                        |
| ---------------------------------------------------- |
| A 00 81 04 01 A0 30 02 84 08 30 02 81 01 00 82 01 01 |

## Table - Response Example <a href="#ref222757634" id="ref222757634"></a>

| Example (Hex)                             |
| ----------------------------------------- |
| AA 00 81 04 82 A0 30 02 82 04 01 00 00 00 |


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