tbc

Example:

output:
   name         : H2 history
   description  : Provides to nOutput_HTTP a history service to access the previous values for each attribute.
   chSubscribe  : nattrmon::cvals
   waitForFinish: true
   onlyOnEvent  : true
   execFrom     : nOutput_H2
   execArgs     :
      db: "/config/nattrmon_db"