> 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/security/device-lock-feature.md).

# Device Lock Feature

The purpose of locking a device is to disable most of the device’s functionality for use cases that need this extra layer of security. When a device is locked, it will reject all commands except for a few. Use of the device lock feature is optional. It is not required by PCI.

* The device lock state can be either unlocked or locked. The device lock state can be retrieved by getting a property.
* The device lock state can be changed by setting a secure property or it can be changed with a command that requires knowledge of the device lock passcode.
* The device can be configured to always have the device lock state set to locked after a reset or power cycle by setting a property.
* If the device has a display and the device is locked, the welcome screen will display “WELCOME” “Device is Locked”. This screen can be customized.
* The device lock passcode can be changed by setting a secure property or it can be changed with a command that requires knowledge of the current device lock passcode.

Commands and properties to manage the device lock feature:

* [Command 0xEF06 – Change Device Lock State](https://magtek.gitbook.io/magtek-pilot-gitbooks/internal-documentation/index/6.0-commands/6.10-command-group-0xennn-security/6.10.8-command-0xef06-change-device-lock-state)
* [Command 0xEF07 – Change Device Lock Passcode](https://magtek.gitbook.io/magtek-pilot-gitbooks/internal-documentation/index/6.0-commands/6.10-command-group-0xennn-security/6.10.9-command-0xef07-change-device-lock-passcode)
* [Command 0xEF08 – Reset Device Lock Passcode (MAGTEK INTERNAL ONLY FOR NOW)](https://magtek.gitbook.io/magtek-pilot-gitbooks/internal-documentation/index/6.0-commands/6.10-command-group-0xennn-security/6.10.10-command-0xef08-reset-device-lock-passcode-magtek-internal-only-for-now)
* [Property 1.2.3.1.1.2 Custom Idle Page Image Device Locked (Display Only)](https://magtek.gitbook.io/magtek-pilot-gitbooks/internal-documentation/index/8.0-configuration/8.3-property-group-1.2.nnnn-device-settings/8.3.5.1-8.3.5.10-property-subgroup-1.2.3.nnn-user-interface-settings#table-907-property-1.2.3.1.1.1-custom-idle-page-image-display-only)
* [Property 1.2.5.2.1.1 Device Lock State](https://magtek.gitbook.io/magtek-pilot-gitbooks/internal-documentation/index/8.0-configuration/8.3-property-group-1.2.nnnn-device-settings/8.3.6-property-subgroup-1.2.5.nnn-security-settings#table-979-property-1.2.5.2.1.1-device-lock-state)
* [Property 1.2.5.2.1.2 Device Lock State After Reset](https://magtek.gitbook.io/magtek-pilot-gitbooks/internal-documentation/index/8.0-configuration/8.3-property-group-1.2.nnnn-device-settings/8.3.6-property-subgroup-1.2.5.nnn-security-settings#table-984-property-1.2.5.2.1.2-device-lock-state-after-reset)
* [Property 1.2.5.2.1.3 Device Lock Passcode](https://magtek.gitbook.io/magtek-pilot-gitbooks/internal-documentation/index/8.0-configuration/8.3-property-group-1.2.nnnn-device-settings/8.3.6-property-subgroup-1.2.5.nnn-security-settings?q=Property+1.2.5.2.1.3+Device+Lock+Passcode#table-984-property-1.2.5.2.1.2-device-lock-state-after-reset)

Only the following commands are allowed when the device lock state is set to locked:

```
Command 0x1F01 - Reset Device
Command 0x1F03 - Extend Session (Session Management Only)
Command 0x1F04 – Terminate Bluetooth® LE Connection (Bluetooth® LE Only)
Command 0xD101 - Get Property
Command 0xD112 - Set Property (Secured)
Command 0xDF01 - Echo
Command 0xE001 - Get Challenge
Command 0xEF06 – Change Device Lock State
Command 0xEF08 – Reset Device Lock Passcode (MAGTEK INTERNAL ONLY FOR NOW)
Command 0xEF09 – Encrypt User Data
Command 0xEEEE - Send Secured Command to Device
```


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