Incorrect checksum of B & R module when downloading program and DIAG mode

[christoph.hilchenbac (Christoph Hilchenbach)]

Hi Sergei,

checksum errors could be caused by hidden page faults e.g. some code overwrites the memory where the module is stored in DRAM.

During download the _INIT code of of programs is executed while other programs are still running their cycles. This may be the cause why you only get this during project download and not after warmstart.

so all tips of this topic could help:

Troubleshooting Page Faults

1 Overview 1.1 What is a page fault? The processor throws an exception to the operating system if it tries to access an invalid or protected memory location. The B&R operating system logs this type of serious memory violation as a page fault (error 25314). 1.2 What can cause a page fault? Processor memory can become invalid as a result of programming errors such as: Null or incorrect pointer Division by zero Accessing an index of an array which does not exist (i.e. the 11th element of a 10 el…