When a device is configured for combined verification mode (such as "Fingerprint + Password" or "Face + Fingerprint"), the device requires successful verification through all specified methods before granting access. If a user has registered only fingerprint data but the device verification mode is set to "Fingerprint + Password," authentication will fail every time.
If you use ZKTeco FaceDepot or SpeedFace models, authentication failure is often due to light and angle. zkteco authentication failure solution best
The lock open duration setting determines how long the door remains unlocked after successful authentication. If set too short, the door may relock before the user can open it. Additionally, incorrect lock wiring can prevent the door from opening even when the device sends a successful unlock signal. Verify that lock wiring is correct and that the lock type (electric strike, magnetic lock, etc.) is compatible with the device output. When a device is configured for combined verification
Check if the device is full. If "User Count" reaches maximum capacity, new authentications may fail. Delete old users to free space [2]. The lock open duration setting determines how long
On certain ZKTeco devices like the ZK-AL10DB and ZK-AL20DB smart locks, a physical or software lockout switch determines which users can gain access. When the lockout switch is in the red position, only administrator users can open the terminal, while normal users receive error messages despite successful verification. When the switch is in the green position, all users have access.
Establish a regular cleaning schedule for fingerprint sensors, particularly in high-traffic environments. Use a wool-free cloth slightly dampened with water (not solvents or detergents) to wipe the sensor surface gently. For stubborn buildup, adhesive tape can safely lift debris without scratching the sensor.
| | Meaning | Best Solution | |----------------|-------------|-------------------| | -307 | Connection failed (often due to network issues or device not responding) | Check network connectivity, ensure the device is powered on, and verify the device IP address. For detailed -307 error troubleshooting, check if your device requires the Pull SDK. | | -10054 | WSAECONNRESET – connection reset by peer (usually a duplicate IP address or device sleep mode) | Check for duplicate IP addresses on your network. Restart the device and assign a static IP address. | | -6 | Wrong password | The communication password configured in the device's "Security" menu does not match the password used by the software. This can occur if a default connection password has been implemented in newer firmware updates. | | -10 | Transmitted data length is incorrect | Ensure data transmission buffers are set correctly; may require adjusting SDK parameters. | | -5 | Data already exists | The user ID or fingerprint template already exists in the device. | | -4 | Space not enough | Device storage is full; delete old logs or user data. | | -3 | Error size | Data packet size mismatch; update SDK or firmware. |