Sequences – best practices

Sequences in PLC control are extremely common and are used for many different application types and use cases. Controlling sequences correctly, efficiently, and retaining an easy method by which they can be modified is important.

There are many ways to control a sequence, from custom-built sequence management logic to using the GRAPH language. Sequences are inherently application-specific, but their management does not have to be and can be standardized to some degree.

Note

TIA Portal's GRAPH has a pre-built method to create advanced sequences. However, in many circumstances, GRAPH may not be suitable or desired, especially for sequences that interact with other proprietary code. GRAPH is flexible enough to be programmed to do what needs to be done, but it comes with additional functions that may not be desired.

Using constants instead of numerical values

It's very common to see sequences that use numerical values to manage...