COBCH1699 A CONSTANT item cannot be a receiving item

An operation has attempted to change the value of an item specified with the CONSTANT keyword.

You cannot change the value of items marked with the CONSTANT keyword. 

01 field1 CONSTANT VALUE "hello".
set field1 = "goodbye" *> you cannot perform this operation on a CONSTANT item
Parent topic: COBCH1681 - COBCH1700