TNet 3 stores channel data as DataNode. You set it using:
TNManager.SetChannelData("name", value);
For example:
TNManager.SetChannelData("kills", 1);
TNManager.SetChannelData("deaths", 0);
TNManager.SetChannelData("score", 10);
You can then retrieve it using:
int kills = TNManager.GetChannelData<int>("kills");
int deaths = TNManager.GetChannelData<int>("deaths");
int score = TNManager.GetChannelData<int>("score");
That's with the Feb 8th version. With Feb 1st I believe it was called SetChannelOption rather than SetChannelData, and retrieval was via TNManager.channelData.GetChild<int>("score") etc.