Arbitrary Waveform Generator Unit U8793, Waveform Generator Unit MR8790, and Pulse Generator Unit MR8791
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HIOKI Technical Notes Vol. 2 2016 No. 1
phenomena by reproducing the responsible signals with a
generator is an effective way to develop countermeasures.
However, implementing this application requires two pieces
of equipment: a Memory HiCorder and a generator. Since
Abstract ��The Arbitrary Waveform Generator Unit U8793,
Waveform Generator Unit MR8790, and Pulse Generator Unit
MR8791 are waveform generation modules designed to be
installed in the Memory HiCorder MR8847A, MR8827, MR8740,
and MR8741. The U8793 can output standard waveforms such as
sine waves as well as waveforms measured and recorded by those
Memory HiCorders. The MR8790 can output sine waves and DC
signals, while the MR8791 can output pulse signals and signal
patterns. This paper provides an overview of these three products
and describes their architecture and features.
I. IntroductIon
Waveform generators that imitate sensor signals are
used to carry out testing and inspections in the automotive
industry. In recent years, the industry has begun using
numerous sensors with the objective of improving fuel
efciency and safety, necessitating waveform generators
with large numbers of channels. In addition, industry
engineers often must reproduce waveforms that were
measured in the eld and during testing in order to simulate
their occurrence in the lab. The use of separate devices
to measure and generate waveforms during such testing
necessitates troublesome procedures such as conversion by
a computer, driving demand for the ability to perform these
functions with a single Memory HiCorder.
The U8793, MR8790, and MR8791 were commercialized
under the concept of enabling a single instrument to both
measure and generate waveforms, a task that they fulll
when installed in a Memory HiCorder.
II. overvIew
Memory HiCorders are used primarily in the three
applications of troubleshooting, testing, and inspections.
In each of these applications, waveform generators are
often used simultaneously. Hioki customers had expressed
a desire to be able to generate waveforms with a Memory
HiCorder in such applications in order to reduce the number
of setup man-hours associated with preparing the generator
and converting measurement data.
In the eld, noise and other abrupt phenomena have the
potential to cause malfunctions of systems and devices.
Identifying the signals that cause such malfunctions with
a Memory HiCorder and then simulating the underlying
Appearance of the U8793.
Appearance of the MR8790.
Appearance of the MR8791.
Appearance of the MR8847A.
Arbitrary Waveform Generator Unit U8793,
Waveform Generator Unit MR8790, and
Pulse Generator Unit MR8791
Takuma Oya
Engineering Division 1, Engineering Department
Arbitrary Waveform Generator Unit U8793, Waveform Generator Unit MR8790, and Pulse Generator Unit MR8791
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HIOKI Technical Notes Vol. 2 2016 No. 1
the process of transferring data between the two devices is
troublesome, there has been demand for a single Memory
HiCorder that can both measure and generate signals.
In testing of automobile engine control units (ECUs)
and other components, engineers apply signals simulating
output from sensors or other devices to a circuit board and
then measure the board’s behavior with a Memory HiCorder
in order to determine whether the board is defective. The
number of simulated signals applied in this manner has
increased along with sensors use in automobiles, leading to
demand for multichannel capability in signal generation as
well.
Furthermore, since automotive components generally
operate at a battery voltage of +12 V, tests are carried
out at +12 V ±20%. Since typical waveform generators
produce output of up to +10 V, an amplier must be used
when applying signals in excess of that voltage; however,
when simulating minuscule uctuations in signals such as
sensor output, the addition of amplier noise to the signal
is problematic.
To resolve these issues, Hioki developed three waveform
generation modules that could be installed in Memory
HiCorders. Adoption of a modular design for waveform
generators, which used to be separate devices, enables
outputting of measurement data on the spot as well as
multichannel capability.
III. Features oF the u8793
This section describes the features of the U8793 when
installed in a Memory HiCorder.
A. Output Voltage of Up to 15 V
The U8793 provides an output voltage range of −10 V to
+15 V. As described above, a voltage of approximately 15 V
is necessary in order to provide an adequate margin when
simulating signals used with 12 V automotive sensors and
related parts. The U8793 can output signals of up to +15 V
without the need to connect an amplier.
B. User-Dened Waveform Output
When a user-created waveform or waveform data
measured by a Memory HiCorder is loaded into the
U8793’s memory, the module can output that waveform.
The ability to reproduce and output observed waveforms is
effective in situations where it is necessary to reproduce a
waveform during testing or simulation work, for example by
measuring a waveform associated with a malfunction and
then reproducing and output it.
Observed waveform data can be loaded either from the
Memory HiCorder’s memory or via recording media.
The module also provides the following standard
waveforms: sine waves, square waves (with duty cycle xed
at 50%), pulse waves (with variable duty cycle), triangular
waves, and ramp-up waves at frequencies of up to 100 kHz
(with a setting resolution of 10 mHz).
C. Fully Isolated Channels and Synchronized Output
All output channels are isolated from the Memory
HiCorder and each other.
In addition, the U8793 is capable of generating
synchronized output for all channels. Thanks to its large
number of channels and support for setting the phase
between channels, the module can be used for multi-circuit
simulated signal output and simulation testing.
D. Single-Device Measurement and Signal Generation
Since the U8793 can be installed together with one or
more measurement modules, it is possible not only to output
previously measured waveforms, as described above, but
also to perform measurement while outputting waveforms.
This capability makes the U8793 ideal for use in applications
where it is necessary to measure the response waveform of
an analog signal while varying the output waveform.
Since a single instrument can be used to simultaneously
measure and generate signals, there is no need for a
waveform generator, and no need to secure the space and
power supply that would otherwise be required by that piece
of equipment.
E. Sweep Function
The U8793 can sweep through waveform amplitude,
frequency, offset voltage, and duty cycle (for pulse waves
only). Since sweep functionality can be applied to these
parameters simultaneously, the module can be easily
congured to generate waveforms characterized by complex
patterns.
F. Program Function
The U8793 supports sequence operation in which up to
128 steps are combined and then output in order. Users can
specify a different waveform for each step, choosing from
standard, user-dened, sweep, and other waveforms, and
each step—as well as the entire program—can be repeated
any number of times.
Iv.
archItecture
A. Memory HiCorder MR8847A
Fig. 1 provides a block diagram for the interface
between the Memory HiCorder MR8847A and a waveform
generation module.
Each measurement module includes ROM to which
adjustment data and other information has been written.
After the instrument is turned on, the memory control
FPGA loads information about installed modules and stores
it in a register (Fig. 1, Module 1: 8966). Communication
between the measurement module and the instrument is