Before diving into the details, you may want to review these fundamentals first:

A Basic Example

Suppose you want to send an error message from your PLC to the HMI. You likely wouldn't want to store the translation on your PLC, along with all other language translations.

Instead, you would prefer to send a unique key for this particular translation. The HMI would automatically translate this key into the language currently selected by the user.

That's precisely the purpose of the TranslationsKey data type. It can be used to let HELIO know that a particular String variable should be translated automatically.

How Do TranslationKeys Work?

In the following example, the PLC provides a string variable. However, its data type is set to TranslationKey in the HMI project. This variable currently holds the value "ErrorMessage.500.Title".

The HELIO Runtime checks the variable type, looks up the key in its translations, and renders the translated text in the HMI. In this case, the text is “Not Allowed To Execute This Action”.

translation-keys.png

How to Define Translations and Translation Keys

  1. Import the PLC variable (of type String) into your project using the Data View.
  2. Change its type from String to TranslationKey and link it to the property of an Element inside the Content View. For instance, the title of a Message element.
  3. Ensure your the variable will be set to a unique set of keys, such as "ErrorMessage.500.Title". Typically, these keys are defined in collaboration with engineers from the PLC team.
  4. Use the Translation Manager to add the unique translation keys "ErrorMessage.500.Title", along with appropriate translations for each language.
  5. You're done! HELIO will now ensure that the values provided by your PLC are displayed in the currently active language inside the HMI.

Related Guides

What are Translations and TranslationKeys in HELIO?