Accessing file registers in Mitsubishi QnA

Hi all,

I am using a Mitsubishi QnA-CPU, and I have some problems accessing file registers ("retentive registers") . It seems that when I write a value to a file register, and later on in that same scan I want to read a value from that same file register, the data that was read seems corrupted. The data in the file register itself is OK.

I have also tried it the other way around (read first, write later...), and this provides no problems.

According to the Mitsubishi-helpdesk overhere in the Netherlands this isn't a known problem, and there are no special rules for accessing file registers.
I would like to ask the following questions:
- Has anyone ever encountered similar problems with any type of CPU?
- Does anyone know about any special rules about working with file registers?

Thanks in advance for your reply.

Caspar

I think your program have any mistake.can you post it?

Hereby I have sent the program which causes the problems. This program is strongly reduced, but I could still generate the problem with this program.
I have also sent this program to the Mitsubishi-helpdesk, but they couldn't find anything wrong with it...

Thanks,
Caspar

Hereby I have posted the program which causes the problems. This program is strongly reduced compared to the original, but I could still generate the same problem with this program.
I have also sent this program to the Mitsubishi-helpdesk, but they couldn't find anything wrong with it...

Thanks,
Caspar

Hi there

Just a suggestion. I would think the key to this problem might be the fact that you write and later on in the same scan you read. By implication if you read first and then write it would mean you read the data written in the next scan.

I am not sure if Mitsubishis registers are updated immediately during the write command or only updated at the end of the scan. Hope this will help.

Regards

Okkie le Roux