| Access Granted | A user has presented a credential to a door and they have been granted access |
| Access Pending Door Credential Denied | A user has been denied access through a door because the attempt occurred before the user's Valid From date |
| ACU Bus New Node | A new Expansion controller has been detected on the ACU Bus |
| ACU Bus Node Address Not Assigned | |
| ACU Bus Reset | The ACU Bus has been reset |
| Barred Door Credential Denied | A user has been denied access because they have been barred through the VOLO website |
| Connected | A controller has connected to the VOLO cloud |
| Disconnected | A controller has disconnected from the VOLO cloud |
| Door Closed | A door has closed |
| Door Credential Denied | A user has been denied access because they do not have permission to unlock it |
| Door Credential Unlocked | A door has unlocked because a user with the appropriate permissions has presented a credential |
| Door Exit Button Unlocked | A door has unlocked because someone has pressed the Exit Button |
| Door Forced | A door has been opened but the lock was not released by an Exit Button or credential presentation |
| Door Held Open | A door has been open for longer than is allowed by the Door Held Open setting |
| Door Holiday Credential Denied | A user has been denied access because they do not have permission to unlock it. The door is operating a Holiday schedule which might impact the permissions required for this door. |
| Door Holiday Credential Schedule Active | A holiday is in operation on this door |
| Door Holiday Credential Unlocked | While a holiday is in operation, a door has unlocked because a user with the appropriate permissions has presented a credential |
| Door Holiday Schedule Locked | While a holiday is in operation, a door has automatically locked on a schedule |
| Door Holiday Schedule Unlocked | While a holiday is in operation, a door has automatically unlocked on a schedule |
| Door Holiday Unlock Schedule Active | A holiday unlock schedule is in operation on this door |
| Door Lockdown Disabled | The lockdown has been disabled on this door |
| Dor Lockdown Enabled | This door has been locked down (no users may unlock the door unless they are configured as exempt from lockdown) |
| Door Locked | A door has locked |
| Door Opened | A door has opened |
| Door Remote Unlocked | A door has been remotely unlocked through the VOLO website |
| Door Timezone Locked | A door has automatically locked according to an unlock schedule |
| Door Timezone Schedule Active | An unlock schedule is active on this door |
| Door Timezone Unlocked | A door has automatically unlocked according to an unlock schedule |
| Exit Button Pressed | An exit button has been pressed |
| Exit Button Released | An exit button has been released |
| Expired Door Credential Denied | A user has been denied access through a door because the attempt occurred after the user's Expires date |
| Fire Alarm Active | A Fire Alarm has been triggered |
| Fire Alarm Inactive | A Fire Alarm has been reset |
| Fire Alarm Unlocked | A door has unlocked in response to a fire alarm being triggered |
| General Input 1 High | The input pin has been disconnected from 0V |
| General Input 1 Low | The input pin has been connected to 0V |
| General Input 2 High | The input pin has been disconnected from 0V |
| General Input 2 Low | The input pin has been connected to 0V |
| General Input 3 High | The input pin has been disconnected from 0V |
| General Input 3 Low | The input pin has been connected to 0V |
| General Input 4 High | The input pin has been disconnected from 0V |
| General Input 4 Low | The input pin has been connected to 0V |
| General Output 1 Active | The output pin has been connected to 0V (internally) |
| General Output 1 Inactive | The output pin has been disconnected from 0V (internally) |
| General Output 2 Active | The output pin has been connected to 0V (internally) |
| General Output 2 Inactive | The output pin has been disconnected from 0V (internally) |
| Hardware Reset | A controller has been reset to factory settings |
| Last Will Disconnect | A master controller has lost connection with the VOLO cloud |
| Lockdown Door Credential Denied | A user has been denied access through a door because the door is currently locked down |
| Lost Door Credential Denied | A user has been denied access through a door because they have used a credential that has been flagged as lost through the VOLO website |
| PSU Fail | A controller has lost its mains power supply and has reverted to battery backup |
| PSU OK | A controller has returned to using the mains power supply |
| Remote Reset Occurred | A controller was reset remotely, through the VOLO website |
| Tamper Active | A controller cabinet lid has been closed/replaced |
| Tamper Inactive | A controller cabinet lid has been opened/removed |