Data type conflict (FB/DB)

I'm calling two FBs one is an #AI block and the other is a #Limits alarm block. The interface is the same as other FBs that I am replicating. My problem is if I call the the Limits Block first and give it a DB number of 953, lets say, it creates the instance and fills in the declarations no problem, but when I call the the AI block and give it the same DB it gives be a type conflict of the data block message. What am I doing wrong? I would like both block to point to same DB without creating separate DB instances.
I'm using SIMATIC 7 version 6. Thanks in advance!

That's impossible. If you want only one Instance DB, you need to call both those blocks inside an FB and create instances in the STAT area of that Block.

This is what I have:
STAT 1. FB99 (Analog limit)
2. UDT96 (Parameter)
3. FB96 AI

Network 1 I call FB 96 (I use DB 953 for the instances, it creates no problem)

Network 2 I call FB 99 and I try to use same DB instances but it will not allow me to.

Please advise as to why the instance are not just added to DB 953.

Thanks

Because they are two completely different FB blocks.
Each instance is a separate block that can only be used once.

The way I explained is a MultiInstance DB. See the post below:

http://www.plctalk.net/qanda/showthread.php?t=3137

Thanks

As others have said, each FB uses its own instance DB, especially if they are different FBs. If you want the data stored in the same DB, use the multi instance function mentioned by others.



If you want both FBs to see the same data, pass it in as an INOUT.