Filter

Filter is often used when you are more interested in an average value
over a period of time than any particular instantaneous value.

Filter is a background task.  When a Filter set to ‘Start Filter’ is executed, it’ll continue Filtering until a Filter with the same Output Tag, set to ‘Stop Filter’ is executed.  Execute it when you want to start, stop or change the Filter.

The ‘Input’ Tag is the signal you’d like to filter.

The ‘Output’ Tag is where the filtered value is stored.

Use the ‘Time Unit’ along with ‘Time Between Samples’ to specify how long you’d like to wait between samples.

Use the slider to adjust the filer weight.  The Example shows what the filter would affect a signal.  Press the ‘new example’ to see another example.

 

 

In Ladder: How to execute tasks only once at startup?

Useful for defining the starting value of certain tags or for background tasks.

Note: Since some tools are background tasks, it is not necessary to run them every PLC cycle. If you run it every cycle, the tool will not work properly because you are constantly configuring it.

Just add a "BIT" that will be turned ON right after.

All your lines that only need to start once at startup :

  • must be behind the normally closed "ColdStart" contact.
  • before the line where the "ColdStart" coil is set to 1.

Note: You can use any name for the ColdStart bit.