control net question real quick for yous

I have a program I am trying to learn and am new to controlnet and these type of moves in general i guess so here it is. I have this logic that is moving data as I can see from control net to the I/O flex blocks but my question is why is it mov from the controlnet address to the Input block?? I would think it should move it the other way??? What am I missing??? I have attached a word doc.

Thanks

All looks ok to me.
The move is the data from the IO area to an internal register.
ie from the controlnet flex input card into a Int.
Regards Alan Case

Alan, Thanks for the single reply. This is what I have come up with after talking to my boss.

Due to the asynchronous nature of Control-logix, inputs change states at their own update rates not synchronized to program scans. Here we are using a common practice of copying inputs to tags therefore getting the input changes in sync with the program scans.

If anyone does not agree please tell me more or if you would like to elaborate on this I ask you to, so I can get a bettter grip on it.

Thanks again.

That can be one reason to do the copy but if that is the only reason then use the CPS (copy synchronous) command.
What that does is take an instant snap shot of the bits and copies it in one go.

ie if you were copying absolute encoder inputs to an internal word via the copy command and half way through the operation the encoder moved then state of the inputs would change. You would find the internal word would not reflect the position of the encoder.

Same if you had 16 digital inputs on a card and you copy the 16 inputs into an int. (assumes AB starts the copy from the lowest input)
Start of copy commmand. The inputs = 000000000000001 ie input 0 is on Half way through copy command. The inputs = 100000000000000

At the end of the copy command the internal word would be 1000000000000001
Now this is a condition that never existed but your code will be using these values. The cops is the instruction to use to alleviate this.

Regards Alan Case