Power Monitoring Overview
|| VID (Virtual Instrument Desktop) is an industrial strength control and monitoring system and is used in conjunction
with ModBus or NetCommander monitoring hardware.
For power monitoring we can use clamp on current transformers (see left) which require no direct electrical connection
to the monitored circuit, these do not need to be installed by a qualified electrician.
The easiest current transformer to use provides a DC output of 0 to 5 Volts which represents the RMS current flowing
in the monitored circuit.
The Netcommander measures this voltage and communicates the values to VID over the LAN or even World Wide Web ...
hence the VID software can be geographically separated from the monitored plant, or collect data from several sites,
and the system provides a real time graphical display of power consumption,
whilst maintaining historical data for later analysis.
The software has been tested using Windows ® 2000/XP/Vista/7, however,
the windows may be rendered slightly differently to those illustrated depending on operating system.
Double click on the file Setup.exe which can be found on the Installation
CD (this should auto-start)
You will almost certainly want all the default settings, keep clicking
"Next" and finally "Install" to install VID on your
performed by navigating to "Uninstall VID "
from the Start Menu or using the "Add/Remove Programs" dialogue
from the Control Panel. Any logs or configuration files generated after the installation
will not be deleted, if you want to remove these as well simply delete
the installation directory (by default C:/Program Files/VID) after the un-install completes .
|| The instruments available are 270, 180 and 120 degree meters, horizontal
and vertical meters, horizontal and vertical bar indicators, a representation
of various tanks with varying liquid levels, thermometer, a numeric value
indicator and a graph plotter. many power monitoring scenarios are covered in the supplied configurations,
these may be used, as is, or modified to suite your application.
Instrument characteristics may be changed from the (right click) properties selection panel (left).
The Graph Plotter has extra configuration options concerning data logging. By specifying
a "log file" for the instrument, chart data
is logged to a disk file. There are 60 plotted points to a graph division,
so if an hour per division is specified each point represents one minute
and an entry is logged every minute. The log scale can be specified
from one day per division down to five minutes. Right clicking on a
graph brings up the usual properties selection panel with the addition of "logger tool " this produces
an historical log analyses tool, this will open
with the log file analyses tool, this will allow comparison of historical and current logs to monitor power usage changes over time.
Log Analyses Tool
his form allows the configuration and display of a
historical chart of instrument data over time. The start time
of the chart can be adjusted with the slider. The graph window
is re-sizeable, and multiple graphs can be on-screen at once.
An instrument chart can be accessed from the right click
instrument properties menu. Two log files can be compared, for
example two logs from different weeks, only one channel of the
(up to eight channels) in the log files can be compared at
once, selected by "Cmp Ch.", "Fill
Ch." specifies which channel is made into a
solid colour (channel 2, yellow, is selected above), you can
also use the "fill Ch." to remind
yourself which channel colour is associated with which
channel. The dates on the X axis represent the dates for "Log
File", the comparison log file data will be synchronized
to the same time, but typically a different date. When
comparing Weekly logs as above the comparison data will be
aligned to the same day of the week, and in the case of
Monthly logs, the same day of the Month. Comparing files with
no log cycling is fairly meaningless, but will be aligned by
time of day. information about a particular plot can be had by
left clicking on the chart and a hint box will pop-up as shown
above. The X-Axis time resolution can be changed, if the time
period is longer than the recorder time period data will be
averaged between plots, where the specified time resolution is
shorter, the data will be interpolated between plots. the
chart can be dragged to the left or right to change the time
period (sufficient data permitting) use the down arrows to
access the calender for dates, highlight the hours/minutes
and use the up and down arrows or directly edit the time. "Excel Chart" and "Excel
Log" allow the export of .csv Microsoft Excel
spreadsheet data for the chart or the entire log respectively.
Note the Chart Plot Information box, this
pops up when clicking on any chart whether live or recorded
and displays the values and any annotations at the cursor
position (highlighted vertical yellow line). The log files
must be of .clg file extension or a zipped log file in which
case the ".clg" is replaced by ".zip", by
their nature log files contain many repeated elements and are
so eminently compressible! The "Zip?" buttons allow a outdated log to be converted to compressed zip
format, you cannot zip an "in date"active log
The "Histogram" checkbox,
when checked, causes the chart to be displayed as a histogram,
averaging the values over each division as in the clip
(right), (hint) set 1 hour per div, then the Histogram bar heights will be "units"/Hour.
The chart total "units"/Hour is also displayed top left, this only has a meaning for charts showing consumption rates ir power, gas flow etc.
The "Tariffs" button,
invokes the Tariff Tool
Closes the property selection form.
Log Tariff Analyses Tool
This tool is for comparing actual utility usage, electricity, water, gas, or any other metered resource, against different suppliers' tariff
structures, you can save files describing your own, and alternative suppliers, tariffs. All the data entered into the "Tariff Bands" panel
will be saved on clicking "Save Tariff" allowing you to create new tariff files or modify existing ones.
The tool will calculate the cost for the selected Tariff structure or can search through all tariffs (.trf files) in the folder specified to find the
cheapest supplier for your particular usage pattern. The span of the data to process is initially taken from the underlying chart,
you can select different start/end times by clicking on the chart at the appropriate position.
The Start/End time selection boxes will be loaded from the chart cursor position with alternate clicks or use the "set start time"
check box to specify which to update, alternatively. Remember you can get more data on the chart by reducing the X-Axis resolution.
Some tariff files are provided with the VID installation,
but these may well be out of date or not appropriate for your application, you should maintain your tariff files from the information on your utility bills.
Power Monitoring Scripts
||instantaneus power phase 1
||instantaneus power phase 2
||instantaneus power phase 3
||day time total energy used phase 1
||day time total energy used phase 2
||day time total energy used phase 3
||night time total energy used phase 1
||night time total energy used phase 2
||night time total energy used phase 3
||Instantaneuos power phase 1
||Instantaneuos power phase 2
||Instantaneuos power phase 3
||Instantaneuos power (combined phases)
||Maximum power demand (combined phases)
||Total energy used (combined phases)
||Total Cost (combined phases)
||Minimum phase voltage
||Current phase voltage
||Maximum phase voltage
||Off peak time total energy used phase 1
||Off peak time total energy used phase 2
||Off peak time total energy used phase 3
||Script Data Reset Button
||Duration of data collection since last reset
All the pre-configured power monitoring scenarios use VID scripts,
these are text files (that can be modified with MS NotePad) which use a programming language similar to "C".
The screen shot at the top of this document is a 3 Phase 1000 Amp configuration.
The script is associated with the "LED" just to the right of the "PowerMon" Logo.
The LED flashes each time the script runs. The script monitors the output of the current transformers,
the output of which represents the RMS current flowing in the monitored circuit.
The script derives kW, kWh etc. per tariff band and exports the values via the internal variable set as in the table (left).
The offset "base" is zero by default but can be changed in copies of the driving script if one instance of VID is required to run more than one power monitoring script.
Scripts are provided for 50/100/400/1000 Amp scenarios, with and without voltage transformer support.
Single phase examples are also provided which are useful for sub-metering of circuits.
* Monetary units are undefined, but should be in Pence/Euro cents etc.
** This variable is set to one by the Reset button and monitored by the script. The Reset button will zero all the collected stats.