Overview.
Leveraging Ignition Edge 8 on the groov EPIC and the available Compute Module from Inductive Automation, you can utilize tag scripting to pass tag data from one controller to another in Ignition Edge 8.
Of note, this is an Inductive Automation Ignition solution on moving data. You can find the steps to configure controllers in Ignition in our online training.
In the example below, I have some tag data coming into Ignition from a controller. The tag is called “Circulation_VFD”. I want to write that data to a tag in a second PLC called “WriteValTo”. As you can see “Circulation_VFD” has a value while “WriteValTo” is empty(0).
Double clicking on “Circulation_VFD” opens its tag properties. We are going to focus on the Scripting Section → Tag Event Scripts:
Clicking on the pen icon to the right of Tag Events Scripts opens the scripting window. For this we will use the Value Events->Value Changed Script:
Click into the scripting area and we will use the system.tag.writeAsync(tagPath, value) function. This function takes two parameters, the tag path and the value to write. In the upper right we will select the tag image, and it will open the tag browse window. We can navigate to the tag we are going to right to and select it.
This will place the tag path into the function. Then we can complete it by using the internal parameter currentValue. currentValue provides the current value of the tag we are in. The function valueChanged is run everytime the data or quality changes.
Once you accept and save all changes to the script and tag properties, the tag “Circulation_VFD” with the tag write script will start sending the data to our write tag “WriteValTo”.
Keep in mind this is an Ignition solution that does require the Compute Module.
From here you can adjust the scan rate. Best practices dictates that there is little to be gained by going faster than 250ms.
Please post and let us know if you use this in an application.
(Or if you find the instructions unclear in any step along the way).
