Beckhoff EL28 Series Documentation page 85

Commissioning
Fig. 61: Sample program with variables after a compile process (without variable integration)
Warning 1990 (missing "VAR_CONFIG") after a compile process indicates that the variables defined as
external (with the ID "AT%I*" or "AT%Q*") have not been assigned. After successful compilation, TwinCAT
PLC Control creates a "*.tpy" file in the directory in which the project was stored. This file (*.tpy) contains
variable assignments and is not known to the System Manager, hence the warning. Once the System
Manager has been notified, the warning no longer appears.
First, integrate the TwinCAT PLC Control project in the System Manager via the context menu of the PLC
configuration; right-click and select "Append PLC Project...":
Fig. 62: Appending the TwinCAT PLC Control project
EL28xx-xxxx Version: 2.2 85