Manual(s) - Online Electronics Ltd

AUDIOSCOPE SOFTWARE
OPERATING MANUAL
AUDIOSCOPE MANUAL RevA02 BG 28.04.14
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CONTENTS
1.
1.1.
1.2.
1.3.
1.4.
1.5.
1.6.
2.
3.
4.
4.1.
4.2.
4.3.
PAGE
DESCRIPTION ...................................................................................................... 3
LIVE VISUAL DISPLAY ........................................................................................ 3
AUDIO GROUP .................................................................................................. 3
SNAPSHOT GROUP ............................................................................................ 4
DECODE GROUP ................................................................................................ 4
EXAMPLE 1 – DATA DECODE INTERPRETATION ..................................................... 5
EXAMPLE 2 – SIGNAL INTERFERENCE INTERPRETATION ........................................ 6
SETUP AND TEST ................................................................................................. 7
WINDOWS 7 AND 8 AUDIO CONTROLS ................................................................... 8
INSTALLATION ..................................................................................................... 9
MICROSOFT .NET FRAMEWORK INSTALLATION ..................................................... 9
MICROSOFT DIRECTX INSTALLATION .................................................................. 9
AUDIOSCOPE SOFTWARE INSTALLATION ............................................................. 9
AUDIOSCOPE MANUAL RevA02 BG 28.04.14
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1. DESCRIPTION
Online Electronics’ AUDIOSCOPE software plots the amplitude of audio signals against time
allowing visual monitoring and interpretation of the audio signals generated by Acoustic or EM
receivers connected to the Line In or Microphone input of a laptop or PC. This is particularly
useful when the signal being received consists of an amplitude modulated coded transmission.
The software has several intuitive and useful features such as a live 15 second buffered
display, Y-Scale Adjustment, Pause/Play function, Screen Snapshot function, Audio Snapshot
function and OEL Acoustic Data Transmitter decoding function.
1.1. LIVE VISUAL DISPLAY
The live visual display is 15 seconds ‘long’ and the vertical grey gridlines represent 1 second
intervals. New data appears on the RHS and scrolls towards the LHS. The figure above shows
a Snapshot of some real data from an OEL Acoustic Data Transmitter.
The slide-bar on the left of the graph controls the Y-Scale of the graph. If it is moved up the
pulses will get larger, if it is moved down the pulses will get smaller.
1.2. AUDIO GROUP
The drop down menu at the top of the Audio group is used to select the audio device (installed
on the PC) to capture data from, usually this will be the Line In or Microphone. The audio
output from the receiver should be connected to this device.
The current PC time and date is shown within the Audio group, this provides a time stamp
when using the Snapshot function.
The Play/Pause button starts or stops the visual display. The software starts a 15 second long
buffer of the audio input as soon as a suitable audio device has been selected. If the Pause
button is pressed the visual display will pause allowing the user to examine the signal at their
leisure. In the background the software continues buffering the live audio so when Play is
pressed again the previous 15 seconds of buffered audio will be shown with the newest data
on the RHS of the screen.
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1.3. SNAPSHOT GROUP
If the user has selected a suitable folder using the Select Folder button a screen snapshot of
the current software window and current contents of the 15 second audio buffer can be
captured at any point for subsequent examination by pressing the Snapshot button. If the
display has been paused pressing the Snapshot button will take a snapshot of the paused
screen and the paused audio corresponding to the captured, paused screen.
The screen snapshot will be saved into the selected folder as a *.PNG image with name
<SNAPSHOT YYMMDD hhmmss.PNG> where “YYMMDD hhmmss” represents the current date
(reversed) and time.
The 15 second audio snapshot will be saved into the selected folder as a *.WAV audio file with
name <SNAPSHOT YYMMDD hhmmss.WAV> where “YYMMDD hhmmss” represents the current
date (reversed) and time.
1.4. DECODE GROUP
The software includes an automatic decode function for use with standard OEL Acoustic Data
Transmitters. The horizontal red line shown on the graph represents a threshold level,
whenever a pulse crosses this line one of the 6x counters on the top line within the Decode
group will increment.
In order for the decode algorithm to function the PC audio input level, the Acoustic receiver
audio output level, and the software Y-Scale must be adjusted so that all pulses cross this line
and all background noise is below this line.
When 6 valid groups of pulses have been received the data will be decoded and displayed in
the window on the bottom-left of the Decode group. When a successful decode occurs the time
at the bottom-right of the Decode group will update. This time can be used to predict when to
expect the next periodic data transmission.
The standard OEL Acoustic Data Transmitters transmit 6 groups of pulses representing a 6
digit number (which may represent a time, pressure, temperature or any other data). Each
group is separated by exactly 1.0 second silence and each pulse within a group is separated by
exactly 0.2 second silence. By simply counting the pulses in each group and subtracting one
the data can be decoded. In the example shown below the pulse counts are [ 1 2 3 3 6 9 ]
representing the data [ 0 1 2 2 5 8 ].
This example shows a real signal received in good acoustic conditions where the receiving
hydrophone was able to be positioned approximately 10m from a high power transmitter
installed inside a pipeline subsea. There was relatively little background acoustic noise caused
by vessel thrusters and other sources of subsea noise. In such conditions the automatic
decode function will work reliably and the user need not pay too much attention to the
received signal however in more onerous conditions some interpretation of the signal will be
required by the operator.
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1.5. EXAMPLE 1 – DATA DECODE INTERPRETATION
The example below shows the real signal received in poor acoustic conditions when the
receiving hydrophone was positioned several hundred metres from an acoustic transmitter
installed inside a pipeline subsea. There was significant background acoustic noise caused by
vessel thrusters, rough seas and other sources.
In this case the automatic decode function did not work reliably due to the effects of
background acoustic noise (pulse 9 did not cross the threshold line) however with a little
knowledge the operator successfully decoded the data.
The 6x groups of pulses were relatively obvious.
The operator deduced that there was a missing pulse between pulse 8 of group 2 and pulse 1
of group 3 because there should be exactly 1.0 second between each group of pulses and
exactly 0.2 seconds between pulses within a group. The vertical grey lines represent 1.0
second intervals so there is approximately 1.2 seconds between pulses 8 of group 2 and pulse
1 of group 3 so there is a missing pulse somewhere between them.
The operator used the audio Snapshot function to record the data transmission and listened to
the recording repeatedly to help to interpret the signal, the human brain is exceptionally good
at detecting patterns and rhythms.
By examining the waveform and listening repeatedly to the audio recording the operator
deduced that there was a weak pulse which did not manage to cross the threshold at position
9 and the pulse count was [ 6 9 1 4 1 3 ] representing the data [ 5 8 0 3 0 2 ].
The operator was able to confirm that the interpretation was correct by waiting for the next
data transmission and confirming there were indeed 9 pulses in the second group.
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1.6. EXAMPLE 2 – SIGNAL INTERFERENCE INTERPRETATION
The example below shows the real signal received in average acoustic conditions when the
receiving hydrophone was deployed from a vessel several kilometres from a 24kHz dual rate
acoustic transmitter which was expected to be transmitting a pulse every 3 seconds indicating
the working state of a piece of subsea equipment.
When the operator first deployed the hydrophone and listened to the audio alone there were a
confusing number of pulses detected at a seemingly random repetition rate. The operator was
not confident that a 3 second pulse was being received.
When AUDIOSCOPE was used it became clear that the expected 3 second pulse was present as
indicated by the asterisks below however there were also a multitude of weaker pulses being
received at a much faster and irregular rate.
AUDIOSCOPE showed an obvious difference in magnitude between the 3 second pulses and the
weaker, irregular pulses which was not obvious by listening alone. It was later discovered that
a nearby vessels’ dynamic positioning system was working in the same frequency band as the
24kHz transmitter and causing these weaker, irregular pulses.
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2. SETUP AND TEST
The instructions below describe how to connect an audio signal to a laptop running the
AUDIOSCOPE software. Usually this signal will come from an Acoustic or EM receiver.
Before beginning ensure that Microsoft .NET, Microsoft DirectX, and the AUDIOSCOPE software
have been successfully installed on the laptop following the instructions provided in this
manual.
1.
Following the relevant manuals set up the Acoustic or EM receiver frequency and gain so
that a clear signal can be heard.
2.
Connect the audio source from the receiver to the Line In or Microphone connection on the
host PC. Plug a pair of headphones into the Headphone connection on the laptop.
3.
Confirm that the same audio heard earlier from the receiver can now be heard in the
headphones connected to the laptop. This confirms that the laptop is receiving a good
quality signal and that the laptop settings and levels are configured correctly. If no audio is
heard or you are unsure of the correct settings then refer to section 3 WINDOWS 7 AND 8
AUDIO CONTROLS for a starting point.
4.
Start the AUDIOSCOPE software.
5.
Select the audio device which the audio source has been connected to from the drop-down
menu in the Audio group at the top-left of the window. Usually this will be the “Primary
Sound Capture Device”.
6.
Press the Play button to start viewing the input signal amplitude against time. At this point
the signal may or may not be too big to see.
7.
Adjust the Y-scale slider within the AUDIOSCOPE software until pulses similar to those
shown are received.
8.
The horizontal red line shown on the graph represents the threshold level, whenever a
pulse crosses this threshold, one of the 6x counters on the top line within the Decode
group will increment.
9.
Ensure that all levels are adjusted so that all pulses cross this line and all background
noise is below this line. Fine adjustment of the Y-scale slider can be achieved by clicking
on the slider and then using the keyboard up and down arrow keys.
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3. WINDOWS 7 AND 8 AUDIO CONTROLS
Note that these settings are relevant
to Windows 7 and 8 which are Online
Electronics’ usual operating systems.
Different operating systems will have
similar controls and these instructions
can be used to help understand them.
With the receiver turned on and
plugged into the Microphone input on
the laptop and a pair of headphones
plugged into the Headphone output of
the laptop follow the steps below.
From the desktop right click on the
grey speaker symbol in the taskbar
and click on Playback devices to open
the Sound control panel shown.
From within the Sound control panel
Playback tab double click on the
enabled Speakers device (green tick
indicates the device is enabled) to
access
the
Speakers
Properties
window shown.
On the Speaker Properties Levels tab
adjust
the
output
volume
and
Microphone volume to 50% as shown.
Ensure that both are not muted.
Move to the Enhancements tab and
ensure Disable all sound effects has
been selected.
Press OK to confirm changes and
return to the Sound control panel.
From within the Sound control panel
Recording tab double click on the
enabled Microphone device to access
the Microphone Properties window
shown.
On the Microphone Properties Levels
tab adjust the Microphone level to
10% and the Microphone Boost to 0.0
dB as shown. Ensure that the
microphone is not muted.
Move to the Enhancements tab and ensure Disable all sound effects has been selected.
Move to the Listen tab and ensure Listen to this device has been selected.
You should now be able to hear the audio received by the microphone input over the
headphones. If the sound is too loud then use the normal volume control on the laptop to
reduce the volume.
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4. INSTALLATION
There are three stages to the software installation described below. Ensure that the software
has been installed and tested well in advance of when it will actually be required.
4.1. MICROSOFT .NET FRAMEWORK INSTALLATION
The software supplied by Online Electronics requires the Microsoft .NET Framework to be
installed on the host PC. For more information about the .NET Framework, or to download the
latest version, visit www.microsoft.com/net. The latest version can also be found on the
memory stick supplied by Online Electronics and can be installed by following the instructions
below.
1.
Log into the host PC as an administrator with full administrator rights.
2.
Execute the dotNetFx40_Full_x86_x64.exe file found in the .NET folder on the memory
stick.
3.
Follow all instructions provided on screen to complete the installation.
4.2. MICROSOFT DIRECTX INSTALLATION
The software supplied by Online Electronics requires the Microsoft DirectX Multimedia
Application Programming Interfaces to be installed on the host PC. For more information about
DirectX, or to download the latest version, visit http://www.microsoft.com/en-gb/download.
The latest version can also be found on the memory stick supplied by Online Electronics and
can be installed by following the instructions below.
1.
Log into the host PC as an administrator with full administrator rights.
2.
Execute the DXSETUP.exe file found in the DIRECTX folder on the memory stick.
3.
Follow all instructions provided on screen to complete the installation.
4.3. AUDIOSCOPE SOFTWARE INSTALLATION
To install the software supplied by Online Electronics follow the instructions below.
1.
Log into the host PC as an administrator with full administrator rights.
2.
If a previous version of the AUDIOSCOPE software is already installed uninstall it using
Start menu > Control Panel > Programs > Uninstall a Program.
3.
Execute the setup.exe file found in the AUDIOSCOPE folder on the memory stick.
4.
Follow all instructions provided on screen to complete the installation.
5.
The software will now be available in the Start menu.
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