Building Flight Recorder

This OpenMUC application automatically logs available channels and provides the logged values for further analysis. The main features are:

• Automated configuration of channels to log from driver's channel scan (updated periodically)
• Common sampling and logging intervals, synchronized to full hours for better post-processing
• Blacklists for devices or channels that shouldn't be logged
• Data will be formated in tables for export
• Optimized export format for Microsoft Excel
• Time-based average for logged values (planned)

The following sections describe the implemented features in detail.

Automated channel configuration

Every time the component will be initiated as well as periodically afterwards, all installed drivers will be scanned for new or updates devices and channels. The update interval is 24 hours by default and can be changed using the org.openmucextensions.app.recorder.updatePeriod system property (value in milliseconds). The component first retrieves a list of all installed drivers and performs a scan for devices as well as a scan for channels afterwards. If the scan returns channels that aren't configured yet, new channel definitions will be created and stored in OpenMUC's channels.xml file. Drivers that don't support scan for channels will be ignored, a warning message will be logged in this case. Drivers, devices or channels that should be ignored (thus that shouldn't get logged) can be defined in a blacklist file. The following table shows all system properties that influence the behavior of the automated channel configuration:

Property	Description	Default
loggingInterval	The logging interval that will be set for new channels in ms	60.000
samplingInterval	The sampling interval that will be set for new channels in ms	10.000
updatePeriod	The automated channel configuration update period in ms	86.400.000 (24 hours)
blacklistFilename	The blacklist filename	./conf/blacklist.xml

All properties start with org.openmucextensions.app.recorder., so the full property name is this prefix followed by the property name in the table above. OpenMUC automatically synchronizes the logging timestamps with full hours.

Blacklist configuration

Drivers, devices or channels that should be ignored can be defined in a blacklist file. The following example shows a valid blacklist file with blocked drivers, devices and channels:

<blacklist>
  
  <drivers>
    <driver>driverId1</driver>
  </drivers>
  
  <devices>
    <device>deviceAddress1</device>
    <device>deviceAddress2</device>
  </devices>
  
  <channels>
    <channel>channelAddress1</channel>
    <channel>channelAddress2</channel>
  </channels>
  
</blacklist>

The default filename for the blacklist file is blacklist.xml in the OpenMUC conf/ directory.

Data export using the Apache Felix Gogo console

The component provides a console command for exporting logged data. The data export format is optimized for processing in analysis applications like Microsoft Excel. The following table shows an example of the export data format:

Timestamp	Channel_01	Channel_02	Channel_03	...
2000-01-01 00:00:00	value	value	value
2000-01-01 00:15:00	value	value	value
2000-01-01 00:30:00	value	value	value
2000-01-01 00:45:00	value	value	value
...

Start and end time as well as the interval between two timestamps can be set. If data is missing for a certain timestamp or channel, the field in the table is left blank. Note that the logging interval and the interval in the export table must be concerted.

The console command for exporting data is exporttable with scope recorder. Type help exporttable in the console to get a short usage description. The command has the follwoing format:

exporttable filename startTime endTime interval

Start and end time must match the pattern yyyy-MM-dd HH:mm:ss. Because of the space character between date and time, double quotes must be used. The interval will be specified in minutes. The follwing example shows a valid command:

exporttable ./export.csv "2000-01-01 00:00:00" "2000-01-31 23:59:59" 15

The command exports a table like shown in the example above with data between Jan, 1^st 2000 and Jan, 31^st 2000 with an interval of 15 minutes. The export file includes a header with the channel ids and the data as comma separated values (CSV).