I’m not sure you understand what the spindle does. The HITECO ELECTROSPINDLE is a 3-PHASE ASYNCHRONOUS MOTOR MODEL: QE-1F 7.5/6 24 63F NC CB (the manual is too large to attach).

When the electrospindle is spinning I currently receive a signal from the electrospindle (signal S3) which pulses 3 ON and 2 OFF for every rotation (as per the drawing). This can be at varying frequency due to the possible RPM of the spindle.

I would like to decode this to a digital output that when spinning (pulsing) is set high and when stopped (not pulsing) the digital output is set low.

Sorry I appear to have confused things. All I’m trying to establish is whether the spindle is spinning or not spinning. So, my thinking is whilst it is spinning (input is pulsing) set output high, whilst it is not spinning (input is low), set output low.

Whether the pulse is 3 On, 2 Off or 3 On, 3 Off doesn’t really matter as it is still pulsing.

I’m not trying to decode its position based on the number of pulses.

I believe something like the attached image

May be another option is to monitor the input for Low signal over a period of time, indicating stopped and setting output low. Any ideas would be really appreciated as I’m totally new to Logo

You can see how important it is to provide a precise description of what you want to create right from the start.

Now it is only important to know the frequency with which the impulses arrive at the Logo. This is decisive for which logo you can use for it and whether it is even feasible.

According to Siemens, a normal input has an input frequency of 4Hz. A switch-off delay that is switched after an edge evaluation (AND (edge)) is then sufficient. The time for the switch-off delay must be dimensioned in such a way that the switch-off delay remains switched on at the lowest speed.

If the input frequency is higher (up to 5 kHz) you need a Logo with fast inputs (e.g. Logo-24CE). You should also use a counter to evaluate the fast impulses. This was recently a topic in the German part of the forum.

If the input frequency is greater than 5 kKz, this cannot be implemented directly with the Logo.

On-delay timer are not suitable, because you don't know, wether the signal stops on high or low signal. Then you have to use edge blocks and this is useless work.

The digital threshold trigger is the best solution for this, but i would prefer a lower value than 290, e.g. 10 to be sure, the decelaration of the spindle has ended.

Regards, Scorp