The unit entrance guard failed to call the room number.

The reasons why the cell access control failed to call the room number can be summarized as follows:

1. Access control system failure, which may be caused by hardware failure or other reasons.

2. Network communication failure, access control system needs to communicate through the network. If there is a problem with the network, it will also lead to the inability to call the entrance guard.

3. The configuration is incorrect, so it is necessary to check whether the configuration of the access control system is correct.

The solution can try the following steps:

1. Check whether the room number is entered correctly and re-enter the room number.

2. Check whether the access control system works normally. You can try to use other access control systems or contact the hotel.

3. Check the access control system for faults, and contact maintenance personnel or property management in time when necessary.

4. Try to use the standby access control system or other entrances and exits.

If the above methods can't solve the problem, it is recommended to contact the property or maintenance personnel in time.