In the EnviroMon System all units are issued with an address, which
is written on the converter at time of purchase.
At times you may find multiple converters with the same address.
The addresses have to be unique thus the configuration will not be
successfully completed if units are trying to share a common address.
To change a converter address the application called 'change
converter address' is used. This should be installed during the
installation of EviroMon software.
- Start Change converter address application.
- Connect the logger to the PC, only one converter should be
connected at a time.
- Select the new address number and select the port that the
logger is connected to.
- Program the logger and then use read back to check the address
has been changed correctly. Change the number on the converter as a
reminder of the converters address.
- Repeat 2 - 4 for other converters
Publishing EnviroMon data on a web site
The latest version of EnviroMon software allows data (graphs, raw
data and alarm status) to be displayed live on a web site.
Applications for this technology fall into two areas, the first is
allowing your customers to view data. For example a holiday resort or
swimming pool may wish to publish graphs of temperature & humidity
data to attract visitors. Similarly if you supply or store products
that are sensitive to heat, humidity or light (food, pharmaceutical
products, document storage, classic cars etc) then by publishing data
onto a web site you can demonstrate that correct conditions have been
maintained.
A second application area is the remote viewing of your own data.
Examples include the remote monitoring of fridges, freezers and HVAC
systems. Because the data is uploaded to a web site it is possible to
view data from several different sites (which could even be in
different countries) simultaneously.
A working example, and full instructions can be found at:
http://www.picotech.com/dynamic/
In normal operation PicoLog data logging software collects up to 1
million readings in one data file and then stops.
There are however a number of options to decide what happens at the
end of a run, these are selected from Settings | Recording within
PicoLog Recorder.
Repeat immediately is useful when you need to
collect more than 1 million readings, or wish to have several smaller
files (one per day for example)
Repeat after delay is useful for taking snapshots
of data, a typical use would be collecting one minute of high speed
data every hour.
Scroll mode discards the oldest samples, this is
useful if you only wish to have a record of the most recent data.
IP networking with PicoLog
The PicoLog IP socket facility can be used to take measurements on
one or more computers, but record the data on another computer.
The measurements are taken by PicoLog running on one computer
called the client. Another computer, the server, requests the data via
an IP network.
For a step by step guide visit:http://www.picotech.com/applications/ip_networking.html
It is possible to use more than one converter on a single PC and
display all channels with the same copy of PicoLog. For example if you
need sixteen channels of temperature measurement, use two eight
channel
TC-08s on the same PC. Different products can also be mixed on the
same PC, for example a TH-03 could be used at the same time as an
ADC-200.
Multiple-converter operation is available only in 'Real time
continuous' mode. Each converter must have a separate port: you can
use either standard serial/parallel ports or our
USB adapters
To configure PicoLog to use multiple converters:
- Choose File | NewSettings
- Check the 'use multiple converters' box
- Continue the set up process in the normal way
PicoLog general hints and tips
Below are some 'cool features' within PicoLog software that you may
not be aware of:
Support for multiple converters. With PicoLog software you can use
a mix of our products on the same PC at the same time. For example you
could use a TC-08 to record temperature on 8 channels and a ADC-16 to
record voltages from another 8 channels. PicoLog will record and
display from all 16 channels.
To enable support for multiple converters, select File | New
Settings and click on the 'enable multiple converters' button.
'Save As' options. When you collect data in PicoLog it is saved as
default as a PicoLog data file (.PLW extension). By selecting File |
Save As from the PicoLog recorder you also have a number of other
choices, these are:
Settings Files (.pls) which contain all the settings, but no data,
this is useful for storing different setups for later recall.
Text files (.txt) which store the data in simple
ASCII text format which many programs can import.
Comma separated values (.csv) which most spreadsheets and data base
programs can import.
Running multiple copies of PicoLog
PicoLog is designed so that you can collect data from multiple
devices connected to the same PC, the only limitation is that data is
collected from each device at the same rate.
If you have more than one converter connected to one PC and need to
log data from each converter at different rates, you can run two
copies of PicoLog Recorder.
- Set up PicoLog for the first converter and save the settings as
a PicoLog settings file (*.pls) eg. fred.pls You then need to set up
PicoLog for the second converter and save the settings with a
different filename, eg jack.pls
- Quit PicoLog Recorder
- Start the first copy of PicoLog with the command c:\pico\plw32.exe
fred.pls
- Start the second with the command c:\pico\plw32.exe jack.pls
- You now have two copies of PicoLog Recorder running, enabling
you to collect two independent data runs.
Trigger in PicoLog (fast block only)
Triggering in Picolog is available, but only in fast block
mode. To use this open the Recording window:
File | New Settings
In the 'Recording Method' dropdown box select the
option 'Fast Block'. When using this mode you will only
be able to use one convertor at a time. Click OK.
Select the Unit that you want (Not all units are available,
only units that can be used with Picoscope). Click OK.
Add the channel and select 'trigger'.
Click the 'Trigger enable' check box.
Choose the direction that you want the trigger to action
on. eg rising the voltage is increasing. Falling the voltage
is decreasing.
In the Threshold box enter the voltage level that you
want the trigger to action.
Autosetup Button in PicoScope
We have added an autosetup button to the toolbar of our PicoScope
software application (release 5.12.5) for PC Oscilloscopes. Pressing
this button sets up the timebase, channels and trigger configuration
to display any signals that the software finds on the oscilloscope's
inputs. The new feature supports all our converter products.
Oversampling with the PS3000 series
Oversampling is a technique used with oscilloscopes and spectrum
analyzers to reduce noise and effectively increase resolution and
dynamic range.
To look at an 1kHz sine wave on an oscilloscope, you might record
1000
samples at 10kS/s. If however you take 4000 samples at 40kS/s and
then
average together blocks of 4 samples you will have reduced any
random
noise pick up and effectively increased the resolution of your
sampled
data by 1 bit.
The PicoScope 3206 can sample at 200MS/s and collect up to 1 million
samples. This performance is far more than is required for some
applications such as when looking at audio signals. By oversampling
the data by 256 times, you can effectively increase the resolution
of
the oscilloscope from 8 bits to 12bits.
The main disadvantage of oversampling is that it can slow down the
screen update rate as more samples have to be transferred back to
the
PC, with the fast USB2.0 interface of the PicoScope 3000 series this
effect is minimal. The other potential disadvantage is that
oversampling acts like a low pass filter so has the effect of
reducing
or removing high frequency signals. This is usually not an issue
for
the spectrum analyser where you have chosen the frequency range of
interest, but can be an issue when using the oscilloscope as it may
suppress spikes and other signals you wish to observe.
With the PicoScope 3000 series it is possible to set different
oversample settings for the oscilloscope and spectrum analyser. To
do
this open win.ini (usually in c:\windows) in a text editor such as
notepad. Next find the section that starts with [PicoScope for
Windows] and add two additional lines as follows:
MaxScopeOversample=1
MaxSpectrumOversample=64
In the above example, we have set the scope oversample to 1 (no
oversample) this ensures any high frequency spikes will be displayed
properly. If you wish to filter an oscilloscope trace to remove
random noise, try using the Current | Filtered display mode instead.
By setting the spectrum oversample to 64 we effectively gain 3 extra
bits of resolution, so increase the dynamic range of the spectrum
analyser. The max oversamples can be set between 1 and 256, but
please note that it is not always possible to oversample. For
example
if you set the spectrum analyser frequency to 100MHz then the
hardware
is already sampling at 200MS/s therefore no oversampling is
possible.
To save a trace in Picoscope as a JPEG (.jpg) file:
File | Save as |
In the dropdown box labelled 'Save file as type' select the jpg
extension. Now enter the name of the file in the 'File Name' box, not
forgetting to include the .jpg extension and removing the astrix (*).
Finally click OK or select the directory where the file is to be saved
to and then click OK.
For many measurement applications, noise is a big concern. A
typical example in the automotive field is measuring injector current
using a current clamp. The signals from the current clamp are only a
few mV in amplitude, yet nearby are ignition signals of many kV.
The best way to minimize noise is to try to eliminate it at source,
in the above example keep the current clamp as far away from ignition
components as practical and ensure all connecting leads are screened.
Physical precautions as described above will help minimise noise
pickup, simple software filtering can often be used to further reduce
its effects.
PicoScope oscilloscope software has several display modes that can
be used to reduce noise pickup, the differences between these modes
are described below and can be selected from the settings | options
menu:
Current (Unfiltered)
This is the default display mode, it takes all the data captured by
the oscilloscope and maps it onto the PC monitor using a min/max
algorithm. This ensures any fast transients are displayed, but will
also act to highlight any high frequency noise.
Current (Filtered)
This mode applies a simple low pass filter to remove high frequency
noise from the oscilloscope display. This mode would be ideal for the
automotive application described.
Average
This mode build up an average trace based on all cycles captured. This
is useful for removing random noise from repetitive signals.
Min, Max and Average
This displays this displays a shaded area showing the minimum and
maximum of all cycles captured. In addition it displays the average
trace as well. As with the average mode, noise is removed from
repetitive signals, in addition the shaded area gives an indication of
how noisy the signal is.
A number of automotive users have asked about optimising the
oscilloscope settings for measuring secondary ignition waveforms and
in particular ensuring that peak kV is measured correctly.
Ignition waveforms can be difficult to capture as the event occurs
over a relatively long period of time, yet contains a spike (plug kV)
of very short duration. This combination requires both a high sampling
rate and a large buffer memory.
The first step is to ensure you are using PicoScope R5.09.4 or
later (in PicoScope select Help | About to check the release number).
If you need to upgrade, this can be done free of charge from the
web site.
Downloading the standard version of PicoScope will not remove the
automotive features from the automotive software.
Most users will start from the Automotive drop down menu - this
gives an acceptable waveform in most cases. If however you lengthen
the timebase to view multiple ignition waveforms, then the peak kV
spikes may not be displayed reliably. This problem can be solved by
increasing the number of samples captured. To do this select Setting |
Options and click on the "Advanced" button. Next change the maximum
number of samples to 32,000 for the ADC-212/3. Click on OK twice to
complete the changes.
To save the settings for future use, either select File | Save
Settings,
or save a reference waveform using File | Save As.
PicoScope software has over thirty automated measurements available
such as frequency, rise time, duty cycle, THD, SINAD, etc.
These measurements are selected from the Settings menu and appear
at the bottom of the oscilloscope or spectrum window. As well as
displaying current values, it is also possible to display minimum,
maximum and average values. Additionally it is also possible to set
test limits and alarms, in this way it is possible for example to set
an audible alarm to occur every time the rise time of a signal exceeds
a certain threshold.
More information on measurements can be found in the PicoScope help
file.
PicoScope, our oscilloscope software has the useful ability to save
a waveform to disk (complete with a time / date stamp) each time a
trigger event occurs. This can prove invaluable when tracking down
intermittent faults, especially those that happen infrequently over a
period of hours or days.
The trigger mode can be enabled by selecting Settings | Trigger. By
default a maximum of 100 waveforms will be recorded to disk (to avoid
filling you harddrive). This default can be overridden by editing the
settings in the WIN.INI file as shown below:
- Using a text editor such as notepad, open WIN.INI (usually in
c:\windows)
- Find the section called
[PicoScope for Windows]
- Add a line
MaxSOTFiles=200 (where 200 is the
maximum number of files you wish to save)
- Save WIN.INI and restart PicoScope
Thick trace lines in PicoScope
If you are using PicoScope for a demonstration to a group of
people, or are visually impaired, you may find that the trace is
difficult to see. It is possible to thicken PicoScope's line thickness
to increase visibility
- Choose File | Setup | Colours
- Adjust the line thickness
- Choose OK
Loading reference waveforms in PicoScope
A common requirement with oscilloscopes is to compare 'live'
waveforms with stored 'reference' waveforms.
This can easily be done in PicoScope as follows:
- Open the reference waveform
- From the View menu select 'Freeze/thaw one'
- Press the new scope icon to open a second oscilloscope window
- Display the 'live' waveform in the second oscilloscope window
If the two scope windows have exactly the same settings (timebase,
trigger, voltage etc) then the waveforms can be overlaid by choosing
'New Composite' from the View menu. More details on this can be found
in the PicoScope help file manual under 'Composite View'.
PicoScope general hints and tips
Below are some 'cool features' within PicoScope software that you
may not be aware of:
+Bar graph option in meter view. As well as the normal numeric
view, there is also an option to turn on a bar graph view. To enable
this, just select Settings | Parameters and click on the bar graph
tick box. An example can be found at:http://www.picotech.com/auto/current_clamp.html
+Trace thickness. If you wish to view scope or spectrum traces from
a distance, or if you have a large number of people viewing the
screen, you may find it helpful to use a thicker line to display the
trace. This can be done by selecting File | Setup | Colours, which
gives you the option of thin, medium and thick trace lines. You can
also change the colours of the traces and backgrounds using this menu
option.
Technical tip - measurements and alarms in
PicoScope
PicoScope has over thirty automated measurements. Oscilloscope
measurements include frequency, rise time and pulse width.
Spectrum measurements include THD, SFDR and SNR.
For each measurement, upper and lower alarm limits can be set.
This makes it possible for example to set an alarm if a pulse width
goes
out of specification. To add an alarm, first add the Measurement you
wish to use using "Settings | Measurements | Add"
>From the resulting dialog box enter minimum and maximum values to be
used then click OK. From "Measurements | Options" you can
select the action to occur on alarm, the choices are to either stop
the scope (so capturing the error on the screen) or to sound an
audible alarm.
Technical Tip: Faster Screen Update Rate in PicoScope
*In PicoScope there is a setting that limits the number of screen
updates per second. This is to prevent PicoScope from taking all of
the PC's resources and preventing other applications from working.
You can find the "Maximum displays per second" control by selecting
File | Setup | Display.
The best setting depends on the PC you are using and the product you
have connected.
* When using a parallel port product without internal buffer memory
(ADC-100 and below) it is best to set the figure around 10. If you
have a very slow PC, a lower number may be better.
* When using parallel port products with a buffer memory, try a
setting the control to 20, or for a fast PC you can increase this to
30 (the maximum allowed).
* For USB products the best setting is normally 30, unless you have
a slow PC.
Spectrum Analyser Options
The spectrum analyser built into the PicoScope software has a number
ofpowerful options that can be accessed by selecting 'options' from
the 'settings' menu. These include:
No of spectrum bands - this defines how many "bins" the frequency
range will be divided into. It can be set between 256 and 16384
(product dependant). Lower numbers give a faster update time,
higher
numbers give more resolution.
Window Type - this gives seven options on how the edges of the block
of sampled data are filtered to reduce distortion. For most users
the
default window (blackman) is adequate, the PicoScope help file gives
more details on which window should be used for which application.
Display Mode - this offers three options. "Normal" displays the
spectrum for the current cycle. "Average" gives a moving average of
successive cycles which is useful for removing random noise. "Peak"
displays the maximum of all cycles (useful for bandwidth testing of
filters and
amplifiers.
X & Y Scales. These give options for the vertical scale to be in dB
or Volts and the horizontal frequency scale either to be in linear
or
logarithmic form.
Exporting data to spreadsheets
Data can be exported to a spreadsheet using EnviroMon for Windows
or PicoLog by copying a pasting from their spreadsheet views. Data can
be exported from PicoScope by choosing Edit | CopyAsText and pasting
into the spreadsheet.
Alternatively, a Dynamic Data Exchange (DDE) can be used. This is a
convenient method of transferring the current set of readings to other
applications. Data is updated continuously, about once per second. To
read the current values from PicoLog, PicoScope or EnviroMon for
Windows, respectively, into Excel, type the following command into a
spreadsheet cell:
=PLW|Current!Value
=PSW!View1|Text
=EMW|Current!Value
Or for Quattro Pro, type in the following command into a cell:
@DDELINK([PLW|Current]Value)
@DDELINK([PSW|View1]"Text")
@DDELINK([EMW|Current]Value)
For more information of DDE see the 'Dynamic Data Exchange' section
of the 'Technical Information' Chapter in the PicoLog, PicoScope or
EnviroMon helpfiles.
Choosing and using thermocouples
Many requests received by our support department relate to the
selection and use of thermocouples. Typical questions are which type
of thermocouple is best for a given application and how will long
thermocouple leads affect accuracy ?
Answers to these questions (and many more) can be found in our
thermocouple application note
Windows XP install
When using Windows XP you must be logged in with 'computer
administrator' privileges in order to install software.
If you wish to use an old software version that does not have the
option to install for XP, please select Windows NT/2000 as the
operating system (Windows XP is built on a 2000/NT code base)
Using a Picoscope as a data
logger
Even if you don't own a purpose-built
Data Logger, you can still use your Pico PC Oscilloscope
with our PicoLog software to log data. Since PicoLog
running in real-time continuous mode can log up to 1 million
samples direct to the computer's memory, you are not limited
by the scope's internal record length.
For newer scopes, streaming mode lets you log even more
samples at up to 1,000 per second. For example, the
PicoScope 2104 handheld scope has a record length of 24 k
samples, but you can still use it to collect millions of
samples with PicoLog. At 1,000 samples per second, a
million samples would give you a recording time of over 16
minutes.
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