Logging data

With the Multi Channel software you can automatically record your measurements to disk. Different file formats can be used to store the data. This page shows how to use your TiePie engineering oscilloscope as a data logger.

Data logger applications

Several ways of logging can be used for different situations. In general, two different types of logging can be distinguished:

  • Triggered
  • Continuous

Triggered logging can be used in situations when the event of interest is occurring every once in a while. By adjusting the instrument trigger settings such that it will trigger only on the event, all events of interest will be measured. When logging is enabled, all these measurements will be stored. You can for example use triggered logging to detect unusual voltages on power lines. By measuring the power line voltage and triggering when the voltage is out of the normal range, unusual voltage peaks can be detected and recorded.

Continuous logging can be used in situations when the measured signal has to be monitored continuously. Examples of such measurements are temperature logging, power logging, power line voltage monitoring and current logging. Any voltage or sensor output can be measured continuously and recorded to disk. Besides logging measurements directly, it is possible to process measured data first. You can for example measure the current through, and the voltage over a load, multiply the two measurements to get the real power, and write the result to a file.

How to log data

You can log data in different ways. Measurements can be stored with the AutoDisk function to the TiePie TPS file format. In TPS files the data as well as the instrument settings are stored. Below you can read more about the auto disk function.

It is also possible to automatically store data to other file formats, such as Matlab data files (.MAT), binary files (.BIN), Comma Separated Values files (.CSV) and Wave audio files (.WAV) with the DiskWriter sink. This object can store 'normal' oscilloscope measurements, as well as streaming measurements. Below you can read more about using the disk writer.

Logging with the AutoDisk function

The Auto Disk function can be used to store all measurements of an instrument to TiePie engineering TPS files. Besides the measured data, the TPS files contain the instrument settings. Each measurement is stored in a separate file.

Auto Disk popup

To start logging measurements of an instrument, right-click the instrument in the object tree, and choose AutoDisk.... A save dialog will appear in which you can enter a file name. After choosing the file name, the auto disk function is ready to store all measurements and a window as depicted below will appear, displaying the progress. A file number is appended to the file name for each measurement. The number starts at 000000 and is incremented after each measurement. All measurements of the instrument associated with the auto disk function will be stored until the Stop button is pressed.

Auto Disk window

You can review the stored TPS files in different ways:

  • Use File->Load... in the main menu
  • Use Load... in the instrument's menu
  • Drag the file from an explorer window onto the Multi Channel software
  • Double click the file in an explorer window

When you load a TPS file with recorded data, the data is processed by the processing blocks that are connected to the instrument. This can be very useful when you want to perform some kind of processing on auto disk measurements.

Logging with the Disk Writer

With the Disk writer sink object you can store the data of any source to several file formats, unlike the auto disk function, which can only store measurements to TPS files. An advantage of this is that you can process your measurements before storing them. For example you can use a low-pass filter to filter out noise, or sum different channels to store the result. You can find more information about the DiskWriter sink on the page about the object tree.

Another advantage over the auto disk function is that the disk writer can be used to store streaming measurements. During streaming measurements, measured data is transferred to the computer in real-time, without using the instrument's memory. Because of this, it is possible to perform very long measurements and store them to disk. Files with a size up to 2 GB can be written.

Streaming measurements can be performed with the following TiePie engineering USB oscilloscopes: Handyscope HS3, Handyscope HS4, Handyscope HS4 DIFF, Handyprobe HP3 and TiePieSCOPE HS805.

Disk writer popup

To start logging, first create a disk writer object by right clicking Sinks in the object tree and choosing the disk writer. A new disk writer object will now be created. By right-clicking the disk writer, a popup menu will show in which several settings can be changed. Entering a file name in the settings window of the writer is required.

When all settings are correct, you can connect the source(s) of which you want to store the data by dragging it/them onto the writer. If you want to store all channels of an instrument, you can drag the instrument instead of the single channels. After the objects are connected, all data will be recorded.

You can use several disk writer objects at the same time to store data in different file formats or locations simultaneously.