Instead of passing a reference to DB1, pass "_var1".data which will then copy _param1 and hand it to your FC.

You will of course have to change the datatype of _var1's data to UDT_1.

ProgIga

Hi all!

TIA V16 Upd5, CPU 1215C DC/DC/DC V4.4.

When I set the DB block option to "Data block write-protected in the device", an error occurs.

Why?

The block is used in the function as an Input parameter.

Data from the block is only read.

---

[snip]

Having the sample program has been helpful to assist you -- thank you.

The problem is the configuration of the UDT. The UDT cannot specify that the type is writable, if you are using it to define a read-only DB. See below:

I have tested it in Step7 V17.

ProgIga

I removed the "Writable from HMI/OPC UA/Web API" option for the UD_1 type. It did not help.

Also, I removed this option from the tag with type UDT_1 in DB (I made a second DB, "Global DB"). It did not help.

In the third DB "Global DB" the tag with type (standard array) has this option, but there is no error!

Perhaps it is best if someone with Step7 V16 try out what you are sharing. To make attachments on this forum, please put your files into a ZIP archive. Some users will not open an external link to get the files.

UPDATE
I have updated the 2nd project to V17. I can see no issue.


Consider doing compile and rebuild.


Even though DB3 has the write enable switched on, the data type in FC3 has the option inactive.

Perhaps you do you feel it is something that needs an official answer from Siemens. Be welcome to use the "Support Request" link on this web page and report this case to them.

ProgIga

 Would you be so kind as to send this project to support?

I realise that you may have a situation that make it difficult for you to directly contact Siemens. But no - I will not help you with your request. I am not employed by Siemens and have no direct way of reporting your issue.