How To Fix TPDA310 - Only simple data types can be displayed in the SY variable field

SAP Error Message - Details

• Message type: E = Error

• Message class: TPDA - Debugger

• Message number: 310

• Message text: Only simple data types can be displayed in the SY variable field

What causes this issue?

The system field display that is
available in the upper right area of the new
Debugger allows you to enter your own field names in the lower field.
The purpose of this is to enable you to freely select a system field
(that is not the default SY-TABIX) and then monitor it.
However, you can generally only use fields with a simple type
(C,N,D,T,I,P,F) in this field.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Select a simple field for the system field display.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message TPDA310 - Only simple data types can be displayed in the SY variable field ?

  The SAP error message TPDA310 indicates that there is an issue with the data type being used in a context where only simple data types are allowed. This typically occurs in ABAP programs or reports when trying to display or manipulate complex data types (like structures or internal tables) in a way that only supports simple data types (like integers, strings, or floats).
  Cause:
  The error is triggered when:
  
  You attempt to display a complex data type (like a structure or an internal table) in a field that only accepts simple data types.
  You are using a SY variable (like SY-SUBRC, SY-INDEX, etc.) in a context that expects a simple data type.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check Data Types: Review the data types being used in your program. Ensure that you are not trying to assign or display complex data types in places where only simple data types are allowed.
  
  
  Use Simple Data Types: If you need to display or manipulate data, extract the specific simple data type from the complex structure or internal table. For example, if you have a structure, access its individual fields that are of simple data types.
  DATA: lv_value TYPE string.
  lv_value = your_structure-field_name. " Accessing a simple field from a structure
  
  
  Debugging: Use the debugger to trace where the error occurs. Check the variables being used at that point in the code to ensure they are of the expected type.
  
  
  Refactor Code: If necessary, refactor your code to ensure that complex data types are not being used inappropriately. This may involve changing how data is passed around in your program.
  
  
  Documentation: Refer to SAP documentation or ABAP programming guidelines for more information on data types and their usage.
  
  
  Related Information:
  
  SY Variables: The SY structure contains system fields that provide information about the current processing state in ABAP programs. Familiarize yourself with the SY structure to understand which fields are available and their data types.
  Data Types in ABAP: Understanding the difference between simple and complex data types in ABAP is crucial. Simple data types include elementary types like CHAR, NUMC, INT, etc., while complex types include structures, tables, and references.
  ABAP Development Guidelines: Following best practices in ABAP development can help avoid such issues. This includes proper data type management and understanding the context in which data is being used.
  
  By following these steps, you should be able to resolve the TPDA310 error and ensure that your ABAP program runs smoothly.