I work with STPM34 and STPM33. I want to make a relay protection terminal with it. You have to take readings very quickly. Every 20 milliseconds.
How i think it working:
1) RMS current and voltage registers count RMS value 200 milliseconds and then then reset the registers and start again.
> Or the register is never reset to zero. Continuously counting samples over the last 200 milliseconds. Old ones are removed, new ones are added.
2) When we do latching at this moment the main register is zeroed or continues to count? As I understand it, it just takes a snapshot of the value RMS registers into the register latch.
3) If I take values once every 20 milliseconds, will this be true?
