Knowledge database

Measure, calculate, save – ring buffers are a thing of the past

As described in detail in the previous article, our latest-generation measurement devices offer very powerful signal processors (DSP), which enable continuous and seamless recording of current and voltage as well as the calculation of all conceivable parameters. How does this happen in detail, how does the measurement process work, in what form are measured values available and where are they stored?

Modern measurement devices such as our UMGs can basically be thought of as PCs. The main elements are CPU (DSP), RAM, hard disk (flash memory) and communication ports (RS485, RJ45).

A basic distinction is made between the following measured value types:

Events

Events include overvoltages, undervoltages, and overcurrents. This is based on the 20 ms full-wave RMS values for the UMG 604 and UMG 508 and the 10 ms half-wave RMS values for the UMG 605 and UMG 511. If the defined tolerance limits are exceeded or not reached, the event is saved to the flash memory. In addition, a run-up and lag time period is defined so that the network activity can be analyzed directly before and after the event occurs. As a result, all voltage and current channels are displayed graphically and coherently over the specified evaluation period.

Messen-Berechnen-Speichern-Ereignis-Unterspannung
Fig.: Voltage dip/undervoltage event recording

Transients

The full performance of the UMGs is required to record transients. At a sampling rate of 20 kHz, it is possible to record transients from 50 μs. As for recording events, threshold values as well as run-up and lag times can be defined. In the same way, you can specify which channels are recorded as waveforms at the same time as transients occur in a graph.

Messen-Berechnen-Speichern-Transientenaufzeichnung
Fig.: Transient recording
Measure-Calculate-Store