Wiegand Access Control reader or keypad is transmitting incorrect credentials or incomplete format data
If incorrect credentials are being transmitted when scanning to add a card or keyfob to a user or when adding an unknown format, it is possible that the device's wires are reversed, or that there is some form of interference.
How to resolve:
- Verify the device's wires are connected to the correct terminals.
- If the reader or keypad is connected to an expansion, verify the Clock (D1) and Data (D0) wires on the RS-485 bus are in the correct terminals
- Verify that the reader's Hold wire is not making contact with any other wires, hardware elements or connected to any of the terminals.
- Verify that the wires are secure in the reader terminals and that there is no exposed wire making contact with any other wires on any other part of the board.
- Verify that the cards and keyfobs being used are compatible with Alarm.com.
- For a list of compatible card formats, see Which Access Control card formats does Alarm.com support?.
- If using a keypad, consult the manual to confirm the keypad outputs a format that is compatible.
- If using a keypad reader, consult the manual to confirm that it transmits using the Wiegand or OSDP protocol and that it is configured to work with a door controller.
Note: Some Wiegand readers or keypads may be compatible but require additional programming to work with a third-party controller. These settings are often referred to as Wiegand Mode or Front End Mode. - Verify the reader's wire is correctly run from the reader to the controller or expansion.
- To test and rule out any sort of interference, connect the reader directly to the controller or expansion without any additional wiring. If this resolves the behavior, there may be an issue with the wire run or potentially some interference that is causing data corruption.
- It is recommended to use shielded wiring for readers to prevent interference. For more information, see Which wire gauge should be used with Access Control Card Readers?.
- Verify the reader is getting sufficient voltage. Consult the reader or keypad manual to confirm the required peak voltage can be supplied by the controller, expansion, or power supply used.