6.2 File-Recorder

The File-Recorder logical device provides a simple facility to write measurement or state values in regular intervals to a file. In user configurable intervals, the File-Recorder writes a line consisting of a time stamp and up to 4 measurement values to the file. A file size limit may be defined to prevent the File-Recorder from creating arbitrary sized files.

Device window pages

The following table shows which device window pages are available with this individual device type. Tool-bar functions not mentioned here are described at the general description of device windows .

• --- This page contain only one button which launches a History File Viewer to display the recorded data graphically.
• --- The device info page.
• --- The maintenance page. The configuration parameters from this page are described below.

Configuration parameters

At the maintenance page of the device window there are a couple of configuration parameters which must be set to interconnect the File-Recorder device with the devices which origin the measurement values to record.

• parameter --- description

• channel1Id --- The message identifier of the parameter to record as 'channel 1'. If left empty, an empty column is written to the file for this channel.

• channel2Id --- The message identifier of the parameter to record as 'channel 2'. If left empty, an empty column is written to the file for this channel.

• channel3Id --- The message identifier of the parameter to record as 'channel 3'. If left empty, an empty column is written to the file for this channel.

• channel4Id --- The message identifier of the parameter to record as 'channel 4'. If left empty, an empty column is written to the file for this channel.

• interval --- The time mean interval between two lines written to the file. The true interval may vary by about one second. Below some long term intervals, expressed in seconds.

  • 1 hour: --- 3600 seconds
  • 24 hours: --- 86400 seconds
  • 7 days: --- 604800 seconds
  • 30 days: --- 2592000 seconds

• liveInterval --- The time mean interval for updating the live view buffer.

• maxSize --- The maximum file size (KBytes) the recorder will produce. If set to a non-zero value, the File-Recorder backs up the output file to a file named 'XXXX. old.txt' as soon as the size limit is reached. The recent values are written to a new file 'XXXX.txt'. A value of zero disables the file size checking.Using the File-Recorder device with a small 'interval' value may generate a huge amount of data. Limiting the file size is strongly recommended!

• directory --- The location where to store the file recorder's data. By default, File-Recorder devices store their files in the base directory of the sat-nms installation. This is /home/satnms/ in most cases. You may define any subdirectoy of this base directory as the location where this File-Recorder shall store its data. The directory already must exist.When you change a File-Recorder's directory, any existing files in the previous directory are moved to the new one.

File Format

The File-Recorder writes the sample to a file 'XXXX.txt', where 'XXXX' is the device name of the File-Recorder device. The file is placed in the Server's base directory unless the 'directory' configuration setting is set to a subdirectory of this.

The file entirely consists of lines, separated by CR/LF pairs. Each line contains a set of measurement values, preceeded by a time stamp. Columns are separated by semicolons, no space characters are inserted between the columns.

Reading A File From Remote

The file written by the File-Recorder (also the backed up data file, if size limiting is enabled) may be read from a remote computer via http. The URL to read the file is:

http://xxx.xxx.xxx.xxx:2007/XXXX.txt or http://xxx.xxx.xxx.xxx:2007/XXXX. old.txt respectively.

Hereby 'xxx.xxx.xxx.xxx' is the IP Address or host name of the M&C / VLC server, 'XXXX' is the name of the File-Recorder device on this machine.

If the 'directory' configuration setting is set to e.g. 'somedir', the URLs to read the files are:

http://xxx.xxx.xxx.xxx:2007/somedir/XXXX.txt or http://xxx.xxx.xxx.xxx:2007/somedir/XXXX.old.txt respectively.

Variables defined by this device driver