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Meta Events

The Meta Events dialog contains all event sensors that permit grouping and filtering of other events


General Settings

Option Description
Event Dead Time

The event dead time defines a period of time (0 .. 3600 s) after an event during which no new events from the same profile are recognized.

By defining an event dead time you can avoid, for example, that a complex action (person walks through the active image area) triggers multiple events.

Event Counter

The Event Counter (EC) prevents events from being triggered immediately. It only triggers an event if a certain number of events within a defined period of time has been exceeded/reached or not reached, respectively.

Each image will increase the event counter by one, even if multiple event sensors are active at the time.

The event counter can be used, for example, for monitoring a conveyor belt in a production scenario. If fewer events occur than expected during the defined period of time, a malfunction is recognized and the camera triggers an alarm.

Also, the event counter is useful to avoid false alarms of the video motion (VM). Due to the event counter, an event is only triggered when events occur e.g. for as long as two to five seconds. This way, you can make sure that the object is really moving.

Parameter Description
Event Counter Enable

If the event counter is enabled, this event will trigger alarms. The event counter counts all events selected in the Event Selection box.

Individual Events controls if only the event counter is allowed to trigger actions or if individual events may also trigger actions.

Events to Count In the Event Selection list select the events to be counted. Hold the [Ctrl] key pressed to select more than one event.
Individual Events

Specify, whether you want the counted individual events to be saved or deleted. Saved events can continue to initiate actions or messages:

  • ignore events: Actions are only triggered by the event counter.
  • use events: Actions are triggered by the event counter and by individual events that have been selected in the Event Selection box.
Counting Period Define the period of time in which the events are to be counted.
Values: 1 .. 3600 seconds
Event Count Enter the number of expected events.
Values: 1 .. 3600
Condition Define the condition to trigger an event:
More/equal An event is triggered if the expected number of events has been reached or exceeded.
Less An event is triggered if the expected number of events has not been reached.
Start Action Define how often the event is to be triggered:
First The event is triggered only once, i.e. when the condition is first detected.
Every The event is triggered every time as long as the condition is true.

Logical AND Event

This event allows reacting to the occurrence of several events at the same time. Similarly, the camera can react if a certain minimum number of a set of events does not occur.

Parameter Description
Condition

Set when to trigger the event: All triggers if all selected events are triggering, Not all triggers if some of the selected events do not occur.

event list

Highlight the desired events in the Event List. Hold the [Ctrl] key pressed to select more than one event.

Maximum Delay Set the maximum length of the time window in which one of the events selected in the Event list has to occur.
Values: 1 to 3600 seconds
Action Type Define how often the event is to be triggered:
First The event is triggered only once, i.e. when the condition is first detected.
Every The event is triggered every time as long as the condition is true.

Event Logic

The Event Logic feature permits testing source events for their order of occurrence. The event is triggered if one of the events selected in Event Set A and one of the events selected in Event Set B occur within the specified Maximum Time Window. The order of occurrence is optional; it does not necessarily be part of the evaluation (see below).

Note: Events in the event lists that are displayed gray and in parentheses are deactivated; if you intend to use them, configure the desired events in the Event Overview dialog.

The meta event will only be triggered if the interval set in Minimum Delay passes between the occurrence of events specified in the two Event Lists.

When used in conjunction with the video motion detectors or other suitable sensors, the camera can start actions, send messages and record images depending on the direction of motion, for example.

Parameter Description
Event Set A

Highlight the desired events in the Event List. Hold the [Ctrl] key pressed to select more than one event.

All selected events are AND-linked, i.e. only one of the selected events has to occur for an event list to become true.

Event Set B

Highlight the desired events in the Event List. Hold the [Ctrl] key pressed to select more than one event.

All selected events are AND-linked, i.e. only one of the selected events has to occur for an event list to become true.

Order of Occurrence Set the desired order in which one of the events selected in Event Set A and one of the events selected in Event Set B should occur to trigger the logic event:
A → B Triggers the logical event only if one of the events selected in Event Set A occurs first and (after the Minimum Delay has passed) one of the events selected in Event Set B occurs.
A ↔ B Triggers the logical event (regardless of the order in which the events occur) if one of the events selected in an event list occurs and (after the Minimum Delay has passed) one of the events selected in the other event list occurs.
A → !B Triggers the logical event only if one of the events selected in Event Set A occurs first and (after the Minimum Delay has passed and before the Maximum Delay has expired) none of the events selected in Event Set B occurs.
Maximum Time Window Set the maximum length of the time window in which one of the events selected in the Event Set B has to occur.
Values: 1 second to 15 minutes
Minimum Delay Set the minimum delay, which has to pass before one of the events selected in Event List  is accepted.
Values: 0 to 20 seconds

Event Logic Examples

The following two examples show two solutions that are using the event logic features of the camera.

Example 1: Counting Rejected Parts on a Conveyor Belt

Problem: A reject gate at a specific location on the conveyor belt is used to separate good parts from rejected parts. You would like to count the number of rejected parts.

Solution: Define a VM window on the conveyor belt in front of the reject gate. Define a second VM window on the rejects conveyor belt behind the reject gate. Both windows are assigned to different events. It is not sufficient to count the events of the second window alone as Employees can also place rejects on the rejects conveyor belt, which are not to be counted. It takes between 10 and 15 seconds for the rejects from the first to the second window (depending on the speed of the conveyor belt). All parameters for properly setting up the event logic are now known:

Maximum Time Window 15 seconds
Event Set A VM_Belt
Order of Occurrence A → B
Minimum Delay 10 seconds
Event Set B VM_Rejects

Example 2: Granting Access to Persons After Entering a Room

Problem: In order to access the secure area of a museum, persons have to authenticate themselves using a key card within 15 seconds after entering a room; failing to do so will trigger an alarm.

Solution: For detecting the person entering the room, you can use a signal input (event SI_Entry), for example. The maximum time window needs to be set to 15 seconds. Authentication with a key card (another signal input, event SI_Auth) corresponds to Event Set B. If SI_Auth is not detected within 15 seconds (A → !B), the camera triggers an alarm. The settings are as follows:

Maximum Time Window 15 seconds
Event Set A SI_Entry
Order of Occurrence A → !B
Minimum Delay 0 seconds
Event Set B SI_Auth


Storing the Configuration

Click on the Set button to activate your settings and to save them until the next reboot of the camera.

Click on the Factory button to load the factory defaults for this dialog (this button may not be present in all dialogs).

Click on the Restore button to undo your most recent changes that have not been stored in the camera permanently.

Click on the Close button to close the dialog. While closing the dialog, the system checks the entire configuration for changes. If changes are detected, you will be asked if you would like to store the entire configuration permanently.

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