Reading/writing PLC tags from PLC s7-1500

Question

I was wondering if there is any way to read and write values from the PLC tags folder using a custom c# application?

I have tried using Snap7 which is great tool to use and actually got it working, but only reading and writing data blocks and not tags what I am willing to achieve. I haven't tried Libnodave just yet.

Would you please recommend me a way to achieve this and if there is other ways to do this.

Update #1

I partiely understand now how to read and write Merkers. But how about Inputs and outputs such as those?

Update #2

I have setup a watch table and got it working using Python Snap7, but wasn't able to do the same using C#.

Answer 1

Besides any tag value from a datablock, libnodave can get/set input, output and memory tags. Snap7 can also do that. I do not see any problem with that.

Answer 2

Its very easy to read and write using Libnodave. Download latest Libnodave.dll from official site and refer this sample. You will get an idea.