Set the Size of a Fixed String Data TypeAbout this taskUsing the fixed string data type, you can store string data of a fixed size. This is useful when you know exactly what data will be received by Historian. If a value is larger than the size specified in the Data Length field, it will be truncated. Procedure Access Historian Administrator. Select Tags. Select the tag for which you want to set a fixed string data type. Select Collection. In the Data Type box, select Fixed String. Enter a value in bytes in the adjacent field. The fixed string data type is set for the tag.