Periodic Event in RSView32

How do i execute a event every 250 ms. I cant use the system timer because it only updates every 1 sec.

Don't trust the system periodic function in RSView - I have discovered bugs in it when you are updating even a pretty modest amount of tags.

In general, if you need to execute an event 4 times a second then you are better off pushing that functionality into the PLC rather than struggling to do it in the HMI or SCADA. What exactly is it that you are trying to do? Some general advice as well - include what you are trying to do as well as the means you are currently having trouble with, since it helps people suggest alternatives.

Just adding a rotation to some images, i cant use the plc because it is only reading data from the controller every 1 sec. I seem to got it working, but id rather do it in the plc as well.

Create a new Derived Tag model executed at either 0.1 second or "Continuous". Create a memory tag (MyTag)and make it's equation

If (MyTag < 1000) then (MyTag +1) else 0

and you'll have a tag that sawtooths; that should be fine for adding rotation animation.

I would definitely avoid using a periodic event to trigger the sort of animation you are proposing. Remember that each event will normally be recorded in the activity log so four events a second (even if that is possible) will result in a vast amount of recorded data in a very short time.