You can also carry out long-term measurements with TNCscope. The internal ring buffer is saved to a file each time before it is overwritten. Select the Long-Term Measurement check box for this in the trigger settings and select a trigger condition or the "Free Run” setting.
Trigger channel
The following constraints apply to long-term measurements:
- The file name results from the name of the base file, followed by a sequential number. It is recommended that for each long-term measurement you create a separate folder containing nothing but the base file at the beginning of the measurement.
- During measurement a message appears in the header, stating the number and total file size of all files already written.
- The duration of the measurement is limited only by the amount of disk space available on the specified drive. However, you can limit the amount of space made available. Once the maximum amount is reached, continuous storing in files is stopped, but the measurement continues.
Settings - The automatically written files have a continuous timeline. The trigger time is therefore not visible. However, after the measurement, the base file has the correct trigger point and a time axis standardized to 0. Otherwise the measured values in the base file and the most recently written file are identical.
- At very high sampling rates it can be the case that saving to the file takes longer than the time available for a buffer cycle. In this case continuous storing in files is stopped, but the measurement continues.
- The display are not refreshed while data is saved. But the data continues to be recorded, so no measured values are lost.
The file size results from the number of measured points, the number of channels and the buffer size. The time span of a file is determined by the sampling interval and buffer size or the buffer time. The useful maximum buffer size depends on various factors, such as the CPU performance, the memory available, the graphic card and the number of channels, and therefore no general statement can be made. If the buffer size becomes too large, the program reacts ever slower until it can no longer be used. The *.sco file then also becomes very large. Therefore, please note the following tips:
- Limit the buffer size.
- Increase the time between samples instead.
- Limit the number of channels.
- Before starting an elaborate measurement, make sure that enough memory is available and that the sampling rate is not too high.