Sometimes a door may re-lock quicker than expected, which doesn't allow sufficient time for a person to open the door.
The two most common causes for this issue are that the door's unlock time is set too low or the DPI (Door Position Indicator) indicates the door is already open.
Door unlock time is too short
Depending on the reader's proximity to the door, the unlock time on the door may be too short for the user to get from the reader to the door before the door re-locks.
Steps to find and adjust door unlock time
Navigate in Command to the door in question and go to the Settings page.
Select Installer Settings. The configured unlock time will be shown.
This can be extended or shortened by clicking the pencil and entering a new Unlock Time.
DPI indicates the door is already open
The door position indicator (DPI) is a sensor that detects whether a door is open or closed.
When a door is unlocked and has a DPI, the controller waits until the open signal is seen then it re-locks the door, whether or not the unlock time has fully expired. If the DPI signals the door is open when an unlock event occurs, the door will re-lock within a second of the unlock event.
This issue can be seen when:
There is no DPI installed, although the door's configuration has DPI enabled
The DPI is signaling that the door is open when it is actually closed
On the door's page, check the top left of the image by the timestamp. The door will be listed as Open, Closed, or No door sensor.
If the door is indicating Open while the door is physically shut, this is the reason why the door re-locks immediately after unlocking. There may be an issue with the DPI wiring, or the DPI itself.
If no DPI is installed on the door, toggle off the DPI (Door Position Indicator) option from the door's Hardware under the Settings page.
Toggling the DPI off will cause the door to display No door sensor.
If a DPI is installed, yet the door displays Open while it is shut, ensure the wires are fully inserted into the DPI ports on the cassette.
If the door still displays Open, the wiring and the sensor positioning need to be checked.
Another method to check the DPI status is discussed here. The DOOR button on the controller is used to select the door in question, then the EMULATE DPI light is checked. If the light is illuminated, the DPI circuit is complete indicating a closed door. If it is off, then the door is reported Open.
To check the wiring, remove the DPI wires from the cassette and use a multimeter to test the continuity between the two wires. If the multimeter shows the circuit is open between the two wires, the sensor is indicating the door is open. The AC41 expects a closed circuit when the door is closed.
Check the DPI sensor on the door, and ensure that when the door is closed the contact on the frame and the contact on the door are aligned. Misaligned contacts will break the circuit, telling the AC41 the door is open when it is actually closed.