Hi there:

I'm doing some testing on one point from an RTU in an electric substation. I must analize manually the frame in order to comprehend it and being able to detect the value I send from may master system to the RTU.

I've been reading some stuff here and there but is not crystal clear this issue yet.

Does anybody has an idea where I could find this information?

Thank You.

 

I assume that you have visited the www.dnp.org site where they have a small DNP 3.0 primer (http://www.dnp.org/files/dnp3_primer.pdf .

It looks like you have to become a member and/or pay to get the standards documentation.

Your device vendor should provide documentation of their specific implementation and the subset of requests that they support.

Test tools like the ASE2000 Test Set are very good for evaluating the messages.

If you are just starting out, choose the basic (simplest) level 1 commands, since not all products support the level 2 and level 3 requests.

Also with DNP if you use the simplest form of the request (ex. do not specify 16-bit or 32-bit) or a generic poll of the device (I do not have the specific request in front of me now) the device will usually answer with the correct formated response for the data it has. This will give you a clue as to how to request the exact data you need in the request format the the device will accept.