Puzzle about FBD

Hello everyone.

I used to read/write code in Ladders. While this time, when I read a program with Function Block Diagram, I had a puzzle about how the code execute in FBD.

Let's say there are 3 sheets in the FBD. Sheet 1,2,3. And in Sheet 2, there are two operations: move A to B at area C1; move C to D at area B2.

So when running, in which order will the three sheets execute? First sheet1, then sheet2 then sheet3. Or else?

And in sheet2, in which order will the two operations execute?

Thanks in advance!

In general, in most FBD programming, the sheets will execute in order, that is, sheet 1, then sheet 2, then sheet 3, etc.

Within a sheet, in the 1131 spec, and in 90% of the extenstions to it, each block is assigned an 'execution order'. Simple direct-connect inputs are fed to the complex blocks, then each block (element) executes based on it's execution order number. The execution order number is usually assigned by default by the programming package, but can usually be re-assigned by the programmer.

Thank you Rdrast.

But where and how can I see and resign the execution order number of each blocks?