ISW 8350
ISW8350-USB
PROGRAMMABLE
1 PHASE – 3 PHASE
WATTMETER
User Manual
INSTRUMENTS ET SYSTEMES
ZI des Radars, 12 rue Diderot
91350 GRIGNY
tel. : 33 (0)1 69 02 31 56
Fax. : 33 (0)1 69 02 08 93
www.systemes-systemes.fr
ISW 8350
ISW83.DOC 10/01
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ISW 8350
Specifications …………........................................
Safety ....................................................................
Warranty ..............................................................
Operation ………..................……………............
Changing a fuse ………........................................
Selectable Options .............……...........................
Input and Output Terminals ……..….………….
Voltage and Current Ranges.......................…......
External Current Probe …………………..…….
Function …………........………….……………….
Power Measurements ……………………..……...
Reactive Power Measurements ……………..…...
Apparent Power Measurements ……………..….
Power Factor Measurements ……………………..
Frequency Measurements ………….……..……...
1 Phase Measurements ……………………….…..
3 Phase Balanced Measurements ....………..........
3 Phase Unbalanced Measurements ...………......
Remote Control …………………….....…………..
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ISW 8350
Specifications
Notes :
(18°C - 28 °C)
V = measured value
D = digit
Voltage (true RMS AC + DC)
The voltage is measured between phase and neutral.
Ranges :
50V 250V 500V
Resolution :
0.1V 0.1V 1V
Accuracy : 20Hz-1kHz : ± (.5 % V + 2D)
DC :
± (.7 % V + 3D)
Bandwidth (-3dB) :
DC and 20Hz-100kHz
Input resistance :
1.2M 100pF
Manual or Autoranging
Crest factor :
max. 3 at full scale
Overvoltage :
600V
Current (True RMS AC + DC)
Ranges :
internal .5A 2A 10A
External Probe 100mV/A max. 30A
Resolution :
internal 1mA 10mA 10mA
external probe 100mA
Accuracy : 20Hz-1kHz : ± (.5 % V + 2D)
DC :
± (.7 % V + 3D)
Bandwidth (-3dB) :
DC and 20Hz-100kHz
Crest factor :
max. 3 at full scale
Manual or Autoranging
Overcurrent :
100A (.5 sec. every 30s.) (all ranges)
Frequency
Range :
Resolution :
Active Power
Ranges :
Resolution :
Accuracy :
4
1Hz to 1kHz
10mHz to 1Hz
9 ranges from 25W to 5000W depending on U and I
3 ranges with external current probe
10 mW to 10W depending on U et I
(U and I > 1/10 of the range)
20Hz-1kHz :
±(.6% V + 10D)
DC :
±(.8% V + 10D)
Bandwidth (-3dB) :
DC and 20Hz-100kHz
ISW 8350
Reactive Power
Ranges :
9 ranges from 25Var to 5000Var depending on U et I
3 ranges with external current probe
Accuracy (20Hz-1kHz) : (U et I sine wave)
±(.6% V + 10D) (balanced 3 phase network)
±(2% V + 10D) (1 phase network)
Resolution :
10 mVar to 10Var depending on U et I
Apparent Power
Ranges :
Resolution :
Accuracy :
9 ranges from 25VA to 5000VA depending on U et I
3 ranges with external current probe
10 mVA to 10VA depending on U et I
(U et I > 1/10 of the range)
20Hz-1kHz :
±(1.2% V + 10D)
DC :
±(1.5% V + 10D)
Power Factor
Range :
Resolution :
Accuracy :
0 to 1.00
.01
(U et I sine waves and > 1/10 of the range)
±(2% + 3 D)
Isolate Outputs (U, I and P)
The isolated outputs are floating against the measurement circuits and the RS232
interface. The cold point of the output is common with the cold point of the current
probe input.
Connector :
4mm secured banana plugs
Output level :
1Vrms at full scale
Accuracy :
2%
Polarity :
same as displayed value
Output resistance :
10 k
Bandwidth :
typ. 100kHz
Protection:
± 30V
Common mode voltage : ±30V max
Current Probe Input :
The input is isolated from the current and voltage circuits and from the RS232
interface. The cold point of the input is common with the cold point of the isolated
outputs.
Sensitivity :
100mV/A
Frequency :
DC and 20Hz to 1kHz
protection:
± 30V
accuracy :
20Hz-1kHz :
±(1% + 5U) (without probe)
DC :
±(1.5% + 5U) (without probe)
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ISW 8350
Safety:
CEI 1010-1 Cat III 600 V
Interface
RS232 (3 wires. Xon-Xoff. Protocol.
Transmission rate 1200/9600 Baud
All functions and ranges programmable.
Power
Temperature
of d'utilization
Dimensions
Weight
Misc
230 V ± 10 % , 50-60 Hz, max. 10 VA
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10-40 °C humidity < 80 %
240 x 240 x 88mm (L x l x H)
about 1.3kg
10mm Led display for voltage and current
25mm Led display for power
Beeper indicates overload.
ISW 8350
Safety
INSTRUMENTS et SYSTEMES certifies that this instrument has left the factory in
perfect working order, both in operation and safety.
This instrument has been designed and manufactured with great care to bring the user
the best possible safety to the user. If the instrument no longer functions properly or
is damaged, it must be immediately disconnected from the ac supply voltage, from the
measured circuit voltages and returned for repair.
Opening, maintenance, repair and calibration must be carried out by qualified and
approved personnel.
Warranty
Provided it is used under the recommended conditions, this instrument is guaranteed
for a two year period against manufacturing defects and component failure. This
warranty applies to material and workmanship. The instrument must be shipped back
to an agreed repair centre. It will be repaired or replaced without charge. Warranty
repairs are made at the discretion of IES.
Maintenance
Your wattmeter does not need any specific maintenance. Whenever cleaning is
necessary, use a soft material. Avoid water or liquids that may penetrate inside.
Operation
Carefully unpack the instrument and make sure that it was not damaged during
transportation. Insert the power cord on the rear of the instrument and connect to the
ac supply. Switch power on by means of the power switch located on the rear panel.
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ISW 8350
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ISW 8350
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ISW 8350
Symbols used
indicates the possibility of a dangerous voltage
refer to the manual
Changing a Fuse
Before you change the fuse, disconnect the instrument from all
dangerous voltage.
The defective fuse must be replaced using a fuse of the same type and value.
Selectable Options
At start up, the instrument displays first the software version, the transmission rate
and finally the measured values.
Buzzer
Switch OFF the instrument. Hold the  key (Voltage Range UP) in and switch ON.
Release the  key when the measured values are displayed. The new state of the
buzzer is kept in memory until you decide to change it.
The buzzer indicates overange conditions or manipulation errors. It may be switched
ON of OFF (toggle) in the following way:
Transmission Rate
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ISW 8350
Proceed in the same way as for the buzzer but press the  key (Voltage Range
DOWN) at start up.
Input an Output Terminals
The voltage and current measurement circuits use six terminals :



Three red plugs (U1, U2 et U3) for the voltage of the 3 phase network. For single
phase measurements, only the U1 terminal is used.
A black plug for the neutral. It is used only for 1 phase measurements. During 3
phase measurements, it is at the average voltage of the network (virtual neutral).
Two blue plugs for current. The current flows into the instrument from the " + "
plug to the " – " plug. A wrong connection will lead to improper power
measurements. A positive value means that the power is dissipated in the load, a
negative one that it is absorbed by the source.
The current measuring circuit uses no limiter. Before applying power, check
that the circuit breakers of the installation are in order
Important overloads may be applied to the voltage and current inputs even on the
lowest ranges.
Do not apply voltages higher than 600V :


Between the voltage terminals (U1, U2, U3 and N)
between the voltage terminals (U1, U2, U3 and N) and the
current terminals (I+ and I-)
The current circuits accept an overcurrent of 100A during half a second.
Any overcurrent should not be applied before a 30sec. rest time.
The rear panel holds the terminals for the current probe (red plug) and the isolated
outputs (P, U and I). The input and the output are referenced to a common voltage
(black plug).
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ISW 8350
Voltage and Current Ranges
The are three voltage ranges and three current ranges. At start up, the autoranging is
selected (AUTO indicator lit). To switch from autoranging to manual selection, press
any range key. The first pressure cancels autoranging. Further pressures will switch
the range up or down.
The voltage ranges are simultaneously switched
on the three phases.
The EXT indicator shows that an external probe
is used. The internal/external switch (rear panel)
must be in the EXT position. Only one range
(30A) is available.
In case of overange, a bip is emitted and the
display blinks.
Overanges may lead to the impossibility to calculate some values like power. The
power display no value but " - - - - - " .
The voltage displays always indicates the voltage between phase and neutral.
In single phase measurements, the voltage is always measured between phase
1 (U1) and neutral (N). In 3 phase measurements, it is measured between
phases and the virtual neutral.
Measurements with a current probe.
The current may be sensed in the under test circuit by means of a current probe. The
probe must deliver a voltage proportional to the current with a sensitivity of
100mV/A. Under these conditions current and power are read without any correction.
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ISW 8350
The measurements are possible with probes having different sensitivities, but the
results must be corrected.
Do not apply to the probe input voltages greater than 3V rms (about
4.25 V peak).
The input accepts DC and AC voltages. The probe must be connected with the right
polarity. A negative voltage applied to the red plug represents a positive current.
Reversing the probe has no effect on the current value (rms display) but changes the
sign of the displayed power.
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ISW 8350
When measuring power with AC sources, the probe may introduce a small phase shift
in the current which will introduce errors in power display. For example pure
resistive loads may show a small reactive power.
The internal/external switch (on the rear panel) must be placed on the EXT position.
The EXT indicator on the front panel is lit to inform that a probe is used.
Measuring function
The ISW 8350 wattmeter continuously displays the voltage and the current. Both
values are true RMS (AC + DC) and displayed with 10mm LED displays, red for
voltage and green for current.
A third display unit (25mm LED) indicates a value selected by the function selector:
 Active Power (WATT)
 Reactive Power (Var)
 Apparent Power (VA)
 Power Factor (PF)
 Frequency (Hz)
When the x1000 indicator is lit, the values must be multiplied by 1000
(reading in kW, kVA or kVar).
The second selector chooses the network : 1 phase (1 Ph) or 3 phase (3 Ph).
On 3 phase networks, the displays shows the power delivered by the 3 phases.
The loads must be balanced.
Power Measurements
Active Power Measurements are activated by selecting the
WATT function.
The active power (1 phase or 3 phase) is measured as the
product of the current (flowing from I+ to I-) multiplied by the
voltage between phase 1 and Neutral.
In 3 phase measurement, the Neutral is built from the 3 different
voltages. The 3 phase voltages are therefore necessary to obtain
significant results.
The power appears as positive if the power is dissipated in the
load, negative if the power is supplied by the load.
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ISW 8350
Reactive Power Measurements
Reactive Power Measurements are activated by selecting the Var function.
In single phase measurements, the power is calculated from the active and apparent
power. If the measurement leads to inaccurate results, the display is replaces by " - - - ".
In single phase, the reactive power is always positive.
In 3 phase balanced measurements, the reactive power is obtained as the product of
the current (flowing from I+ to I-) multiplied by the voltage between phase 1 and
phase 2. Phase 1 and 2 must be connected in the right order to respect the sign of the
reactive power.
In 3 phase measurements, the reactive power is positive with inductive loads,
negative with capacitive loads.
Apparent Power Measurements
Apparent Power Measurements are activated by selecting the VA function.
It is calculated as the product of the RMS voltage by the RMS current. It includes DC
and AC components.
Power Factor Measurements
Power Factor Measurements are activated by selecting the PF function.
The power is the ration of the active power (Pact) to the apparent power (Papp). It is
calculated in two different ways:
In single phase, the power factor is calculated directly (PF = Pact/Papp).
In 3 phase measurements, if the active power is high, the power factor is calculated as
above. But when the active power is low and the reactive power high, the power
factor is calculated from the reactive power. The choice between the two possibilities
is done to give the best results.
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ISW 8350
Frequency Measurements
The frequency is taken either from the voltage or from the current. Priority is given to
the current, unless no current flows in the circuit, in which case the information is
taken form the voltage until a current appears.
The counter is fed through a low pass filter (1kHz) which rejects undesired high
frequency components.
In this way frequency measurement is always possible. Using the current to measure
the frequency gives better results when driving motors with switched voltages.
The selector must be in the" Hz " position. Counting will be possible only if the
amplitude of the signal (voltage or current) is high enough.
The frequency measurement is deliberately limited to 1kHz to reject undesirable high
frequency noise.
The resolution is automatically adjusted to the best value by the reciprocal counter.
With a counting gate of 100ms, display will be 4 digit, starting from 10Hz.
1 Phase Measurements
The function selector must be placed in the " 1Ph " position.
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ISW 8350
The voltage is applied between the U1 terminal and neutral.
The power is displayed in Watt (Active Power), Var (Reactive Power) or VA
(Apparent Power) unless the x1000 is lit, in which case kW, kVar or kVA must be
read.
3 Phase Measurements (Balanced Networks)
When the network is balanced, the measurements are made according to the diagram
below. The Neutral is not connected.
The selector is in the " 3Ph " position.
The power is displayed in Watt (Active Power), Var (Reactive Power) or VA
(Apparent Power) unless the x1000 is lit, in which case kW, kVar or kVA must be
read.
Reactive and Apparent power measurements are meaningful only if both voltage and
current are sinusoidal.
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ISW 8350
3 Phase Measurements (Unbalanced Networks)
When the network is not balanced , and if no neutral connection is used, the power
will be measured using the 2 Wattmeter method. Two successive measurements are
made. A special wattmeter switch is used. It switches between U13 x I1 and U23 x I2
circuits. The measurement is similar to 1 phase measurements, so U1 and Neutral
lines are used for voltage.
If the two different measured values are P1 and P2, the total power is calculated as :
P = P1 + P2
Isolated Outputs
The isolated outputs give the image of the voltage, current and power.
The current is always the current flowing from I+ to I-.
The voltage is the voltage between Phase 1 and neutral in single phase measurements.
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ISW 8350
If 3 phase is selected, the voltage is the voltage between Phase 1 and neutral and,
during active power measurements and the voltage between Phase 1 and Phase 2
during reactive power measurements.
The power is the product of the displayed voltage and current.
The full scale voltage of the isolated outputs is 1V at full range (e.g. 50V applied on
the 50V range). For power, the full range is calculated as the product of the current
range by the voltage range. Or example a 2A current (2A range) and a 250V voltage
(250V range) produce a voltage of 1V at the power Output.
The Output voltage includes DC and AC components of the signals.
The outputs exhibit a 10k output impedance. They must not be overload to preserve
the accuracy of the displayed value. An oscilloscope with a 1M Input resistance
produce a 1% voltage drop.
The same care must be taken to minimise the capacitance to preserve the 100kHz
bandwidth.
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ISW 8350
Remote Control
To select the transmission rate
You have the choice between two transmission rates between the instrument and the
computer, 1200 or 9600 Baud. The Baud rate is displayed during a short time at start
up. To modify it, switch the instrument off, press the  key (Voltage range down)
for a few seconds and switch power on. The new .selected rate is displayed and kept
in memory until a new change is done.
Communication
To test the communication between the computer and the instrument, install the
program delivered with the instrument. Open the Configuration/Communication
Window and check the communication.
Connection
The dialogue between the computer and the wattmeter is accomplished by means of a
software protocol (Xon-Xoff). The connection needs only a simple 3 wires cable
(Rxd, Txd and signal ground).
The connecting cable can be terminated at one end with a 9 pin connector and at the
other end with a 9 pin or 25 pin connector, this depends on the PC serial port
connector. The following connections should be followed:
25 pin
female connector (PC)
9 pin female
connector (PC)
9 pin male connector
(instrument)
2
3
7
3 (Tx)
2 (Rx)
5 (GND)
3
2
5
RS 232 cable
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ISW 8350
Connexion USB :
To connect your wattmeter ISW8350 to a computer, use the USB cable supplied with
the instrument (type A- type B). When the instrument is connected Windows detects a
new material to be configured. 2 possibilities: Installation of the drivers or installation
of a virtual port to communicate with the instrument as with a traditional interface
RS232 ( hyper-terminal of Windows, PC-DMM1,…).
-To install drivers USB, insert supplied CD IES in the CDROM (ex: D: / ). Follow
the Windows’s instructions and indicate the following directory: D:\Driver USB \
D10620 \
- To install the Virtual Port COM (VPC), follow the instructions of Windows’s
installation. Insert provided IES’s CD. Follow the Windows’s instructions and
indicate the following directory: D:\Driver USB \ R9052154 \ It is possible to change
the number of port allowed to the peripheral. For that, it is necessary to go in the `
Control Panel', then ` System', select ` Material', then ` Device manager', Select the
COM port to be modified, then ` Port settings' of the port', ` Advanced' and change
the Number of the port then click OK to finish. Once, the installation is finished the
instrument is ready to be controlled remotely by the computer.
To check the communications
You can quickly and easily check the connection with the "TERMINAL" option of
Windows™.
First, switch the instrument off and on to check the transmission rate. If you want to
change it see section "To select the transmission rate".
Enter the Terminal mode under Windows™ (or execute the program Terminal.exe).
Select the following configuration in terminal:




TTY terminal emulation
terminal parameters: LF => CR/LF for Input and Output
communication parameters: transmission rate 1200 or 9600 Baud.
8 Bits, no parity, 1 Stop Bit, Xon-Xoff
Send the command *IDN?. The instrument sends back the string:
IeS ISW8350 Vxx , where Vxx is the hardware version number.
Commands
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ISW 8350
The commands are sent as a string of ascii letters and digits. No special symbol or
space should be added. Once sent, the command is executed upon reception of the
carriage return character (CR = Hex 13). In terminal mode, this character is
transmitted by the ENTER key of the keyboard, along with the Line Feed character
which is ignored.
Notes :
 The commands may be written either in UPPER or lower case.
 Data transmission is operated under the Xon-Xoff protocol. Because the
instrument uses a small input buffer, it may overflow before the transmission
stops. It is a good practice to insert a 200ms delay between commands when
successive commands are to be sent.
Some commands will force the instrument to answer. It is the case for the commands:




*IDN? : identification
VERSION? : software version
STATUS? : configuration of the instrument (see § STATUS string)
VAL? : measured value. If the command arrives during the measurement cycle,
the result will be sent only at the end of the cycle.
 VAS? status and measured value query
 MA1 : continuous output mode. Each result is sent to the computer. This mode is
cleared by the MA0 command.
The table of the last page lists all the available commands.
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ISW 8350
STATUS chain
The status chain sent back after reception of the STATUS? command has the
following structure:
AU1
AI2
W3
1P
|
|
|
|
|
|
|
|________ network 1P (1 Phase)
|
|
|
3P (3 Phase)
|
|
|
|
|
|_______________ Function : W, VAR
|
|
VA, PF, Hz
|
|
|
|____________ I Range (0, 1 or 2)
|
auto (A) or manual (M)
|
|_____________ U Range (0, 1 or 2)
auto (A) or manual (M)
The different fields are separated by blanks.
Measurement Result
The measurement result is transmitted :


after a VAL? (value) or VAS? (value and status) query
after each measurement if the device is in the auto transmit mode (MA1
command). In this case it is preceded by the status string of the instrument.
AU1 AI2 W3
Volt =120 E+0
(only after VAS ? or in MA1 mode)
Amp =1.25 E+0 Watt= 150 E+0
When a value is not available (because the calculation would lead to important
errors), the display shows " - - - - " and the transmitted value is replaced by the "NA"
string.
The values is transmitted according to the display and followed by the exponent.
The measurement result is transmitted only at the end of the measurement cycle.
Therefore, if a result is requested during the cycle, the result will be transmitted after
a variable delay (max 400 ms).
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ISW 8350
Automatic Measurements
Once the MA1 command has been sent, the measurement data is automatically
transmitted after each measurement. The output string includes the instrument status
and the value. In this way, the user is continuously informed of the configuration of
the instrument.
The automatic mode is reset by sending a MA0 command or switching off and on the
instrument.
Voltage or Current Range Selection
At start up, the voltage and current ranges are in AUTO mode. The ranges may be
selected in two different ways :
- by sending the MAN_U (voltage) or MAN_I (current) command. The AUTO
range switching mode is cancelled and the previously selected range unchanged.
- by choosing directly a range with the command SET:Ux (x = range 1 to 3) for
voltage or SET:Ix for current. AUTO mode is also cancelled.
To disable the front panel
The front panel may be disabled in remote operation by means of the command
FAV0. The instruments now only responds to the commands from the interface. This
mode is cancelled with the command FAV1 or when the instrument is switched off
and on again.
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ISW 8350
FUNCTION
RANGE
MODE
MISC
WATT
VAR
VA
PF
1PH
3PH
FREQ
SET:U1
SET:U2
SET:U3
SET:I1
SET:I2
SET:I3
AUTO_U
MAN_U
AUTO_I
MAN_I
VAL?
VAS?
STATUS?
FAV1
FAV0
MA1
MA0
*IDN?
VERSION?
BEEP
BEEP0
BEEP1
Active Power
Reactive Power
Apparent Power
Power Factor
1 Phase Measurement
3 Phase Measurement
Frequency
Set 50V Range
Set 250V Range
Set 500V Range
Set .5A Range
Set 2A Range
Set 10A Range
Set AUTORANGE (Voltage)
Cancel AUTORANGE (Voltage)
Set AUTORANGE (Current)
Cancel AUTORANGE (Current)
Measured value query
Status and value query
Status query
Lock front panel
Unlock front panel
Continuously output data
Reset MA1 mode
Identification query
Version query
Beep once
Beeper OFF
Beeper ON
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ISW 8350
TO USE THE PC_W8350 SOFTWARE
Installation and de-installation
Start Windows®. Insert the PC_W38350 floppy disc and execute the file :
or
a:setup to install the software
a:desinst to de-install it
The directory ISW8350 will be created during installation. It includes the icon used
to start the software. If you want to keep the ability to de-install the software, you
must maintain the same structure.
To use the PC_WATT software
Operating modes
Two different operating modes are allowed, the "Terminal" mode and the
"Command" mode. In Terminal mode, the computer only monitors the front panel
of the wattmeter, which is driven with its own keys. In the Command mode, the front
panel is disabled and the instrument is operated with the mouse or the keyboard of the
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ISW 8350
computer. The software starts in Terminal mode. You can modify this mode in the
Configuration menu.
Starting
Connect the interface cable and double click onto the PC_W38350 icon to start the
software. If the software finds the wattmeter, it directly enters the monitor mode.
Else, it opens a communication window where you can modify the transmission speed
or the PC serial port to use.
Display
The Display menu selects the different windows that appear on the screen:


The function/range window which reproduces the front panel of the wattmeter
The communication windows which displays the dialogue between the
instrument and the computer
Help
The help file is opened with the F1 key of the keyboard (dedicated help) or by the ?
menu (global help).
Measurements
The measurements may be accomplished and stored in a file at a desired rate.
The Measure/Start Measurement menu will start the measurement:


In Function mode. Data will be acquired in accordance with the instrument
function (Watt, Var, …)
In Energy mode. The energy (Watt.h, Var.h, VA.h) is calculated and stored.
This mode is available only if Watt, Var or VA function is enabled.
The Options menu opens a window where you can define the maximum number of
measurements, the time interval between measurements and the structure of the object
file.
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ISW 8350
The result file is a text file with
different columns. Each column
represents a file selected in the
proposed list (function, value,
unit, time, date). Note that the
value is always selected.
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