There are four connection options to use for your measurements: Stationary, via Wi-Fi, with the Optical Fiber Cable or Ambulatory.
Multiple connection offers are available to measure with SAGA. In this article, the different options and when to use them are explained. For most types of research, the Stationary Measurement setup will be best fitting when no freedom of movement is required.
For stationary measurements the data acquisition PC and the measurement device are at a fixed location. The Data Recorder (DR) of SAGA is docked on the Docking Station (DS). Advantages of this setting are maximum data throughput and signal bandwidth at all channels, reliable data transmission, precise triggers and unlimited recording time. A disadvantage of this usage is the limited freedom to move for the subject.
This wireless connection gives the opportunity to perform measurements where freedom of movement is important. The Data Recorder (DR) is undocked from the Docking Station (DS) and data is sent from the DR to the DS via Wi-Fi. Disadvantages of this setup are limited bandwidth and possible data loss due to the data transmission. It should be noted that successful wireless data transmission can never be guaranteed. To learn more about what influences the wireless transmission, please read about this here. During the wireless data acquisition, data is automatically stored on the SD card of the DR to overcome data loss. This feature can also be disabled, and more information about recovery of lost data can be found in the manual. To learn more about the considerations for wireless recordings, read more in this whitepaper.
Optical Fiber Cable Measurements
Using the Optical Fiber Cable to perform measurements can be useful if freedom of movement is necessary, but the drawbacks of the Wi-Fi connection are too large for the measurement purpose. The Data Recorder (DR) is undocked from the Docking Station (DS), but the DR is connected to the DS by the Optical Fiber Cable. This setup can mainly be useful in case a larger bandwidth for the data is needed, or when Wi-Fi interference sources are present in the measurement environment. Other useful setups are cases when backup logging is not an option because online data processing is needed, or when sample precise triggers are important. Please note that with this setup, the subject's freedom of movement is limited by the length of the Optical Fiber Cable.
In this setup, the Data Recorder (DR) is used as a data logger. The DR does not stream data to the DS, and this setup is typically used in measurements where the DR is attached to a subject for ambulatory measurements (for example at home). Data is recorded on the SD card and can be downloaded afterwards. In this setup there is a limited data storage bandwidth, which is high enough for the 32-UNI channels, but when using a 64-channel device, a reduction in sampling frequency or number of channels might be necessary. A bandwidth check is provided in the software. Measurements can be started at a predefined time in the software or by pressing the button with the SD Card icon for 2 seconds.
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