Reading and writing UDT

[Alex Fabijanic]

Hello,

Is there a way to get any data type (including UDT) as a bare raw byte buffer? I've been away from AB for some time and things have changed since the PLC5 times - we used to store the UDTs in the (I think) N files, fetching the datablock chunk raw and simply memcpy-ing it on the C structs. 

Is it possible to get any tag content (including UDT data) from the PLC as a raw bytes buffer and map it onto an in-memory C struct?

Thanks,

Alex

[Kyle]

libplctag reads a UDT into a raw byte buffer.  Then you can access it with the data accessor functions.   I would not use memcpy() personally.   The alignment of fields in UDTs is not necessarily the alignment that C has.

There is a data accessor function that copies the raw bytes into a buffer you provide.   

I hope that helps.

Best,

Kyle