title: VOLTTRON publish agent data to message bus
body: <p>I made an agent with the <a href="https://volttron.readthedocs.io/en/main/developing-volttron/developing-agents/agent-development.html" rel="nofollow noreferrer">creation wizard</a>. How can I publish data from this agent to the message bus?</p>
  <p>Ultimately I am hoping to use this agent to calculate some &quot;events&quot; similar to the <code>air_cx_agent</code> and use the forward agent to send it onto the VOLTTRON central instance.</p>
  <p>This is the just code snip from the periodic that runs every 300 seconds:</p>
  <p><code>fdd_check</code> is a boolean True False type calculation from the BACnet data on the BAS.</p>
  <p>I have an issue in the <code>self.vip.pubsub.publish</code>:</p>
  <pre><code>from volttron.platform.agent import utils
  from volttron.platform.vip.agent import Agent, Core, RPC
  from volttron.platform.messaging import topics, headers
  
  
  
  '''
  code snip below from method
  ran by the periodic every 300 seconds
  '''
  
  
  fdd_check = self.fault_condition_one(df_lastrow)
  _log.debug(f'[FC 1 Agent INFO] - fault_condition_one {fdd_check}')
  
  self.vip.pubsub.publish(
      peer=&quot;pubsub&quot;,
      topic=f&quot;{topics.FAULTS_FC1}/{self.ahu_instance_id}&quot;,            
      headers={
          headers.TIMESTAMP: utils.format_timestamp(utils.get_aware_utc_now())
      },
      message=int(fdd_check),
  )
  </code></pre>
  <p>Full Trace back:</p>
  <pre><code>Traceback (most recent call last):
    File &quot;/var/lib/volttron/volttron/platform/vip/agent/core.py&quot;, line 117, in _loop
      method(*self.args, **self.kwargs)
    File &quot;/home/volttron/.volttron/agents/4bddb163-3d1c-403e-8ce0-70a82f58ea1c/fconeagent-0.1/fcone/agent.py&quot;, line 277, in get_stuff_done
      topic=f&quot;{topics.FAULTS_FC1}/{self.ahu_instance_id}&quot;,
  AttributeError: module 'volttron.platform.messaging.topics' has no attribute 'FAULTS_FC1'
  </code></pre>
  <p>In my thinking I would like to relate this topic or data on the message bus to the HVAC equipment it is monitoring via BACnet <code>self.ahu_instance_id</code>, as well as that is FAULTS, and fault condition #1. Can the topics just be made up? Thanks for any tips.</p>