A UIM data table (UDT) contains information that you need to externalize for national language translation, including entries for:

• Unit (device) descriptions
• Parameter descriptions
• Feature descriptions
• Messages

Write one UDT for each UIM. UIMs and UDTs are associated using the 3-digit number at the end of the names. Although a UIM can have more than one UDT (one for each supported language), each UIM has only one active UDT because the language is selected during HCD start up. Each UDT is loaded with its associated UIM. If the UDT's requested language version does not exist, the English version is loaded. However, if a UIM does not have at least an English UDT in the library when another language is selected, the I/O units represented by that UIM are considered unknown.