Access PLC Variables on Datalayer with TIGER / IDE

[Luschuerz]

I am trying to read/write a global variable of a PLC program which is published on the datalayer. My program does not seem to be able to access the variable written on the datalayer. Is there some examples of writing/reading to Datalayer I can access? Or a How to for it? (I cannot find any myself)

Or is it an issue of not being able to read/write booleans?

Edit: I have managed to narrow down the issue a bit, reading anything from the datalayer seems to work just fine. However writing to the datalayer seems to still be an issue, no matter what type of variable I try to write. Even directly writing what is being read does not seem to work, and keeps sending the DL_Type_Mismatch error.

uiState is a UInt16. does that cause an issue?

Thank you

[nickH]

Hello,

Yes there is a How to Use Graphical Programming in the developR series on YouTube. It's about a simple Pick and Place application. 

There our expert does a digital write to a PLC Variable in the Data Layer. 

Maybe this example can help you. 

Best regards, 

Nick

[CodeShepherd · Accepted solution]

There are different possibilities how to read an write variables:

1. You can use the Data Layer base functions:
   IDE visual read/write
   Note at the moment there ar problems with the standard write path. We are investigating this.
   
2. You can use the IPC extension for PLC variables:
   IPC extension read/write
   

   See our online documentation for further information.

   IDE App, Integrated Development Environment, Application Manual  --> Visual Coding  -->  Project settings  -->  Extension configuration and initialization  -->  IPC (Inter Process Communication) extension

[Luschuerz]

Thank you.

I managed to write Booleans, and work around in that manner. However Integers still did not work. I will try with the IPC workaround or writing it directly as a JSON instead of the integer.