Learning from the ground up

Although an experienced programmer, I am brand new to SNMP programming and control. I am trying to learn SNMP++ at the same time as learning how the subject of SNMP control works at the time. We have a power module we need to control with SNMP V3 commands. SNMP++ seemed the most promising, but I am still struggling with it. What is the best place to start to learn how all this works?

Right now I am stuck with user error, and an Invalid argument in the sending packet. Yet near as I can tell the PDU and target information is as good as all the demo code (and digging through your source code) provide. I can’t tell what I have overlooked. I don’t even know where to start on the user error.

Right now I’d give my left arm for a self-test and a PDU serialized text dump to read back what I have loaded.

You could use MIB Explorer Pro to first test how to control the power device with SNMPv3 and debug the response packet including its error status and error index.
When that works, implementing the PDU sending with SNMP++ should be quite easy.