scanning of the program

I have a requirement where scan analog input values and based on the operator input copy one value to axis feedback value. It also does some error checking and generates alarm and discrete output based on that.

I can program these in steps, with multiple commands in each steps. So when the controller scan the program, does it execute all the steps or one step in each scan? What happens after it scans the last step, in next scan it starts again from the first step or I have to put jump to step 1 in the last step?

Now, I need to scan my whole program in each scan. So, should I put all the commands in step 1 only? If that so, then how many commands can I program step 1 and what will be the effect of it on the scan time? I have only one axis so I can configure the controller for 250┬ÁS(RMC150).

Thank you in advance.

The program runs sequentially. For example, Step 1 will execute, then it will wait until the Link condition specifies when it should jump to step 2, etc.
The fastest a user program can run is one step per loop time, which would be the case if you used the Immed Link Type on all steps.
When the user program reaches an End link type, the user programs stops running. If you want the program to loop to the beginning, you need to put in a link type that will do so.

If you need to do the whole program in one scan, then use a single step. There is no set limit to the number of Expression (113) commands or immediate commands in a step (there is a limit, but it is on how many calculations can be done in a loop time, and you are unlikely to hit the limit). There can typically be only one motion command per axis per step.

Thank you Jacob. As you mentioned it is very unlikely that I would hit the limit on the number of calculations in a loop time but if you happen to know please let me know, I just want to make sure I am way under the limit.

To see how much of the allotted user program calculation time you are using, you need to make the Verify Results window stay open after verifying:

  1. On the Tools menu, choose Options.
  2. On the Programming page, in the Verify Results section, uncheck the Automatically close Verify Results checkbox.

To verify the programs, press F7. The Verify Results window will show the time used.

Thank you Jacob.