Hello, everyone.
Let’s see how to make a sequence!
In this video, we’ll show an example ...
... of a simple sequence of how to fill and empty a tank.
Make sure that you have SE.AppSequence library ...
... referenced and up-to-date.
If you don’t know how to do it,
please watch our video, “How to change library reference”.
On the AppSequence library,
drag and drop the Sequence head, “CAT”.
This function block is used to start the sequence structure ...
... and control the operational state of the sequence.
There is a permission to start a sequence.
In this example, we link it to the plcStart.
Now, we need two sequence steps:
one to fill the tank,
and one more to empty the tank.
We have a simple logic to simulate the level of the tank ...
... by a ramp output.
Here, we have its symbolic link.
You need a “SeqTerminate” to end a sequence.
Link all your elements together with a sequence chain adapter.
Don’t forget to map your blocks.
Now, we want to add an action for each step.
We can use either the output interface events,
or we can add an action.
Initialize parameters of the action step.
One can have different types of action CATs.
More information about them, and required data for these blocks,
can be found in the Help documentation.
Let’s make our logic to compare the level of the tank.
Link the condition of the tank level to pass the transition of the step.
Here, you have to add the transition step ID,
which is the next step number to execute.
The current step has ID number 1,
and we want to execute the ID number 2.
ID number 3 corresponds to the sequence terminate block.
Focus point:
you need to add the Function Block “DPAC_FULLINIT”,
inside the resource of your device ...
... for a software and hardware initialization.
Also, for sequence initialization,
you have to add the block “EVENTCHAINHEAD” as shown here.
Don't forget to add the constant name "SEQ_INIT".
Now, let’s create a canvas.
Don’t forget to save your solution.
Drag and drop your Applications CAT Instances.
Each step and transition name, as well as a comment,
can be modified in the Properties tab.
Once your canvas is ready, start the HMI.
You can see your sequence running.
That’s it!
Now you know how to make a sequence!