GX Works3 R series PLC online changes issues
Introduction
This article provides some information on the online changes option in GX Works3 when programming the iQ-R PLC.
Important Pointers
Note 1: There are limited times an online program change can be performed consecutively.
Note 2: The online program change size is also limited (cannot accommodate too large changes).
Note 3: You need to have the latest version of GX Works3. 
Freely downloadable
Sample Procedure Video
The key is not to compile the program BEFORE uploading it to the PLC. Once you compile, then a full download will be required.