Dear all, Lately we have been facing the below issue, I am unsure of how to read the Caddr address in 1500 PLC. Can someone help me?

Added the source file of FB34

Make VERY sure that all the input parameters are filled out. Especially true for those that are of DB_ANY type. Skipping over one of those would cause a "0" value going through which will result in DB0 being opened. DB0 should not be accessed in this way.

In the diagnostic buffer view in TIA Portal is the possibility to open the code at the error position. The button is called "open in editor". This could help further. 

qwazee

Make VERY sure that all the input parameters are filled out. Especially true for those that are of DB_ANY type. Skipping over one of those would cause a "0" value going through which will result in DB0 being opened. DB0 should not be accessed in this way.

In the diagnostic buffer view in TIA Portal is the possibility to open the code at the error position. The button is called "open in editor". This could help further. 

 Thank you Qwazee for this advice, I will check that and come back to you.

Satheesh290692

I have checked and all DBs have been linked to the inputs. 
I have some additional info, This happens only when the CPU is rebooted. Could it be the case that the DB is called when the PLC is still initialising the DBs?
Should I make a code to skip the DB call in the block during 1st scan?

That is a valuable observation. Consider adding a timer to delay when the code processing starts. You may still see a problem which will mean the root cause is with the initialization of the code itself. Especially the child FBs that are called inside the parent FB is of concern.

Good luck.