Hello!
Well it depends on what you want to build.
In the example of the SMA (30) in the 10 minute chart and the SMA (30) in 1-hour chart it builds a cross between them.
So the example is correct...and it should work properly, because the SMA is calculated on the close of a candle.
You can also take different periods, it's up to you.
If you have specific questions please let us know by posting your trading ideas in the language section you prefer under knowledge base i.e..
Cheers!