Data Logging

The Data Logging function allows the measurement results to be stored periodically and automatically to a text file. This enables later analysis of long-lasting processes.

A complete set of necessary results is recorded, from which all other desired quantities, such as return loss or VSWR, can be computed.

A system info is appended to the log file, providing information about HomSoft version, Homer HW and firmware version as well as Homer settings at the moment the logging was stopped. This identifies conditions, under which the measurements were taken.

The log files can be opened and the data processed and plotted using spreadsheet calculators, e.g., Microsoft Excel.

To activate this function, click the View|Logging Window menu item. The Data Logging window (Fig. 22) will then appear. The controls are logically organized into three groups: TIMING, LOG FILE, and PROGRESS.

    

Fig. 22.  Logging window.

To activate logging, proceed as follows:

  • Choose the maximum extent of data recording by editing Days, Hours, Minutes, and Seconds in the Logging Duration row of the TIMING group. The recording will be terminated after either this time has elapsed or the maximum number of logging events has been recorded (see the Records setting below), whichever occurs first.

However, if the logging duration time is set to zero, logging will not be time-limited.

  • Choose time spacing between two consecutive data recordings by editing Hours, Minutes and Seconds in the Sampling Repetition Time row. If the repetition time is set to zero, continuous logging will take place (all received data will be stored).

  • Edit the Records field to choose the maximum count of logging records to be stored in the log file. Unless aborted by the user, the recording will be terminated when either the Records number or the Logging Duration is exceeded, whichever occurs first.

However, if the maximum records count is set to zero, logging will not be record-count-limited.

  • In the Burst Size edit, type logging burst size, i.e., the number of successive samples you wish to be recorded at each logging event. If, for instance, the measurement cadence is 10 measurements/second and you chose Repetition Time = 1 minute and Smpl/Event = 15, then each minute 15 consecutive samples (a burst covering 1.5 seconds) will be recorded. Note that each recorded sample of a given logging burst is assigned the same sequential number. The default and most common Burst Size setting is one.

The Burst Size setting is ignored with continuous logging, i.e., when the Sampling Repetition Time is set to zero.

  • Select the decimal separator by clicking the Point or Comma radio button in the Separator box.

  • In the Info edit, type an optional comment: it will be added at the beginning of the log file.

  • Click the  Prepare  button. The dialog box titled Prepare Log File opens where you choose the path and the name of the log file. The recommended file extension is txt. Click the  Save  button to close the dialog. The name and path of the chosen file are now displayed in the Name and Path panels. If the file has been successfully prepared:

    • The group title changes to LOG FILE - prepared,

    • the originally red Status “lamp” in the Progress group turns yellow and its label changes from Not ready to Ready.

    • The bottom right button  Start  will be enabled.

    • Editing the logging inputs will still be possible but the changes will not be applied until the next click of the  Prepare  button.

  • Define Homer measurement conditions, i.e., sampling mode (the waveform type), sampling parameters, frequency count time, etc. – see Homer Sampling Setup.

  • Start measurement, then press the  Start  button, or vice versa. The logging will not start until the  Start  button has been pressed. Its caption now changes to  Stop .

Following this, the yellow Status lamp in PROGRESS group turns green and its label changes to Logging. The progress is shown in increments of Recorded and Elapsed boxes.

After the stop conditions are met (Recorded reaches Records or Elapsed reaches Logging Duration), the Status lamp turns blue and its label changes to Completed.

To abort data logging anytime before a stop condition occurs, press the  Stop  button. This is the only option when both Logging Duration and Records are set to zero. The Status lamp turns gray and its label will read Aborted.

If you pause or stop measurement while logging, logging attempts continue: the elapsed time increases in the background but the number of records does not. After restarting the measurement, logging continues normally.

Data items in the created log file are separated by Tabs; it is therefore easy to paste them, e.g., to Microsoft Excel. The procedure is exactly the same as described in topic Saving Results to a Text File.