A new real-time mathematics option for the Yokogawa DL850
ScopeCorder introduces many new DSP-based functions that boost the
instrument's power analysis capabilities as well as adding features such
as sensor linearization and electrical to mechanical conversion.
In addition to 30 powerful mathematical functions, the new /G3 option
expands the instrument's standard bandwidth filters with a set of steep
digital filters that can be used for triggering specific measurement
sequences based on waveform characteristics.
With the /G3 option, the DL850 ScopeCorder offers up to 16 real-time
DSP channels and 30 mathematical functions, including calculations of
power, sensor linearization, rotary encoding and mechanical
displacement. The mathematical sampling rate is up to 10 MS/s
(megasamples per second), while the filter sample rate is up to 1 MS/s.
The fast acquisition rate results from the fact that there is no
processing after waveform acquisition apart from a fixed calculation
delay in the DSP channel. In the real-time mathematical computations on waveform data, the digital
signal processor uses the output data of the input module as its source
and outputs the computed data to the acquisition memory of the DL850
Using real-time mathematics, input channels can be multiplied,
divided or integrated, and dedicated functions such as power
integration, 3-phase real power measurements and differentiation can be
carried out. What makes the /G3 option extra powerful is that the
trigger conditions can be set depending on the result of the DSP or
digital filter functions.
Typical applications include using the RMS mathematical operator to
trend the RMS value of each individual cycle of a voltage or current
waveform, or using the (S1 x S2) operator to multiply the voltage and
current waveforms in order to trend the instantaneous power waveform.
To determine the power usage of a system, a power integration
function will trend the integrated power over time in watt-hours or
watt-seconds. A mechanical versus electrical phase function calculates the angle
between the mechanical rotation measured precisely by a rotary encoder
and the input current waveform. This current is often distorted with
harmonics, but the DSP can extract the fundamental component of the
current using a discrete Fourier transform to produce a trend of the
phase difference for display in real time.
The DL850 ScopeCorder is a portable instrument that combines the
benefits of a high-speed oscilloscope and those of a traditional data
acquisition recorder. Because of its large acquisition memory, it is
able to capture and analyse both long term trends over measurement
periods of up to 30 days and transient events with sample rates up to
The range of input modules available allows the DL850 to be
configured up to 128 channels with built-in isolation and signal
conditioning to capture voltages and currents as well as physical
parameters like temperature, stress and vibration. Using input scaling,
all types of physical sensors with voltage output can be connected.
Visit Yokogawa Test & Measurement at www.tmi.yokogawa.com/ea
This article originally appeared on EE Times Europe.