• Height detection of fast moving objects
• Detection of falling parts
• Classification of driving cars in toll stations
• ...

The list of possible applications where speed is crucial is long.

Here is how to calculate if the MLG-2 is fast enough:

1.) Check 'Minimum Presence Time' for desired MLG-2 variant

If you already have the MLG-2 present the easiest way is to connect to it online.

If not use the SDD of the MLG-2 offline! Open SOPAS and navigate to the 'Device Catalog' - search for MLG-2 SDD and drag and drop it into your project. Double click for opening the SDD and choose the desired MLG-2 in the dialog.

Check the 'System Boundaries' section for the timing details:

Definitions for Timing

Scan time

In the MLG-2, not all light beams are active at the same time, instead one light beam is activated after the other starting from the bottom.

The scan time increases according to the number of beams of an MLG-2.
In one scan time the beam status and all basic functions like NBB, LBB, etc. are calculated.
The scan time is used to determine the response times of the outputs, the minimum presence time of an object and the repeat accuracy of a measurement result (reproducibility).

Minimum presence time

The minimum presence time is the time an object or a gap has to be in the detection area for it to be detected. The minimum presence time is max. 2 × the scan time.

Reproducibility

The repeat accuracy of a measurement result (reproducibility) is the amount of time by which an object detection can differ from a previous or subsequent detection. The reproducibility time is 1 × the scan time.

Reproducibility = Scan time

Response time

The response time is the time it takes for an output to react following the detection of an object/gap. The maximum response time is 3 × the scan time plus the transmission time to the outputs.

According to the definitions above the 'Minimum presence time' is crucial for the calculation if the MLG-2 is fast enough for the detection of an object (red circle).

2.) Calculation

Is the light grid fast enough?

Having calculated the time t you just have to make sure that your calculated t is equal or longer compared to the 'minimum presence time' shown in SOPAS.

But for this question we don't even need to calculate:

Have a look at the 'Minimum detectable object length (MOL)' in the 'System Boundaries' (yellow circle).
It already gives you the shortest length of an object which is detectable with the MLG-2 in the current configuration.
Be aware: The MOL value with yellow circle is dependent on the object speed entered in 'Performance Options' → 'Object size / Detection type'

*Times shown in SOPAS may differ slightly to your own calculations because internally the equations use much more positions after decimal point.

What's the maximum speed possible?

Same equation as above - just use the time out of the 'System Boundaries' and you get the maximum possible speed of the objects.
Pay also attention to the aperture of the MLG-2. This needs to be taken into account.

Important:

The settings (in 'Performance Options' Tab) of 'Function Reserve' (e.g. cross beam) and 'Response Time' (e.g. High-Speed-Scan) influence the scan time of the MLG-2 and thus the minimum presence time.
For example with High-Speed-Scan in many applications a significant decrease of the scan time is possible!
→ Make these settings before calculating!