code: def connection_made(self, transport):
          
          self.log.info('Connection established to AVR')
          self.transport = transport
  
          #self.transport.set_write_buffer_limits(0)
          limit_low, limit_high = self.transport.get_write_buffer_limits()
          self.log.debug('Write buffer limits %d to %d', limit_low, limit_high)
  
          self.command('ECH1')
          self.refresh_core()
docs: Called when asyncio.Protocol establishes the network connection.