A bug was introduced in SCN 1912 back in 2008.

The timer interrupt that transfers data between the two processors on the XL must be installed before SERCOS takes over running the operating system. Otherwise, both the timer interrupt and SERCOS will attempt to transfer the data. This causes a timing problem and the 8F00000E occurs as a result.

The code prior to SCN 1912 had the proper protection to prevent this. SCN 1912 conditionally bypassed this code with incorrect logic. All Closed Loop controllers with the SERCOS option need the protection. If the controller had the Multi-Axis option the protection code got bypassed.

Any long delay, such as displaying an error message, prior to installing the timer interrupt could cause the task error to occur. This bug has now been fixed.