Compressed Air Alliance ROG User manual

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User Manual
Rogowski Coil with
4-20mA or Modbus
Integrator
Model: ROG

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Table of Contents
Notices...........................................................................................................................................3
Warnings .......................................................................................................................................3
About Rogowski Coils ..................................................................................................................4
Specifications................................................................................................................................6
Installation –Mechanical.............................................................................................................9
Installation –Electrical ...............................................................................................................11
Warranty......................................................................................................................................13
Need help? ..................................................................................................................................14
Appendix 1 –Modbus Communication Protocol....................................................................16
Appendix 2 –Configuring Modbus using Modbus Poll..........................................................30

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Notices
Please read this manual in full and
carefully observe the notes and
instructions before and during
installation, operation and
maintenance. The manufacturer cannot
be held liable for any damage which
occurs as a result of noncompliance
with this manual.
Do not tamper with device. Should
the device be tampered with in any
manner other than a procedure which
is described and specified in this
manual, the warranty is cancelled and
the manufacturer is exempt from
liability.
The product is designed exclusively
for the described application. Use of
this product in conditions not specified
in this manual or, contrary to the
instructions provided by the
manufacturer, is considered improper
handling of the product and will void
your warranty. The manufacturer will
not be held liable for any damages
resulting from improper use of the
product.
This manual should be read carefully by
relevant personnel and the end user.
This manual should be kept with the
product and be made available as
needed. Once you install or use the
product, you accept that you have
read, understood and complied with
this manual.
Compressed Air Alliance endeavours to
make the content of this manual
correct, but is not responsible for
omissions or errors and the
consequences caused. In case of any
doubts or questions regarding this
manual or the product, please contact
Compressed Air Alliance.
Warnings
Ignoring the warnings can lead to
serious injury and/or cause damage!
When handling, operating or carrying
out maintenance on this product,
personnel must employ safe working
practices and observe all local health &
safety requirements and regulations.
Improper operation or maintenance of
this product could be dangerous and
result in an accident causing damage to
machinery or injury or death.
The manufacturer cannot anticipate
every possible circumstance which may
represent a potential hazard. The
warnings in this manual cover the most
common potential hazards and are
therefore not all-inclusive. If the user
employs an operating procedure, an
item of equipment or a method of
working which is not specifically
recommended by the manufacturer
they must ensure that the product will
not be damaged or made unsafe and
that there is no risk to persons or
property.
NEVER CHANGE ORIGINAL
COMPONENTS WITH ALTERNATIVES.

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About Rogowski Coils
What is a Rogowski coil?
Rogowski coils are a flexible current
transducers that have been used for
the detection and measurement of
electric currents for decades. They
are based on a simple principle: an
“air-cored” coil is placed around the
conductor in a toroidal fashion and
the magnetic field produced by the
current induces a voltage in the coil.
The voltage output is proportional to
the rate of change of current. This
voltage is integrated, thus producing
an output proportional to the
current.
By using precision winding
techniques, especially developed for
the purpose, the coils are
manufactured so that their output is
not influenced by the position of the
conductor within the toroid, and to
reject interference from external
magnetic fields caused, for example,
from nearby conductors.
Basically, a Rogowski coil current
measuring system consists of a
combination of a coil and
conditioning electronics. Rogowski
coil current transducers are used for
AC measurement.
The transducer does not measure
direct currents but, unlike a current
transformer, it can carry out accurate
measurements of AC component
even if there is a large superimposed
DC component, since there is no iron
core causing saturation. This feature
is particularly useful for measuring
ripple currents for example in battery
charging systems.
Rogowski coils can be used in similar
circumstances to current
transformers but for many
applications they have considerable
advantages:
•Wide dynamic range
•High linearity
•Very useful with large size or
awkward shaped conductors or
in places with limited access
•Unlike traditional current
transducers, there is no danger
from open-circuited secondaries
•They cannot be damaged by
large overloads
•Measurement uniformity at any
position of the conductor inside
the coil
•They are non-intrusive
•They are light weighted and in
some applications are light
enough to be suspended on the
conductor being measured
•Excellent degree of rejection to
the external current conductor

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What does the Integrator
do?
The integrator is a built-in analog
integral circuit, which calculates true
RMS and converts the coil’s output
into a 4-20mA or Modbus standard
signal. The integrator is powered by
24VDC.
Rogowski coil output is a weak
voltage (mV) signal. The integrator
has ability to amplify and convert it to
standard signal which can be read by
power meters, your PLC or display.
Rogowski coil output is proportional
to the frequency of the measured
current. The signal equalization
ensures a linear response on a wide
frequency range. The integrator
allows you to use coils on different
electrical network frequencies,
keeping the same output level over
the frequencies.
An integrator is essential to equalize
and shift the output signal from the
Rogowski coils by 90°. It consists of
an active electronic circuit with
negligible offset and a good linearity.
Rogowski Coil
Integrator

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Rogowski Coil with Integrator User Manual v1
Specifications
Rogowski Coil
500 Amps
1,000 Amps
3,000 Amp
Rogowski Coil Size
500 Amps
1,000 Amps
3,000 Amp
Coil Length
200 mm or 7.87”
350 mm or 13.78”
510 mm or 20.08”
Window Size
50 mm or 1.97”
100 mm or 3.94”
150 mm or 5.91”
Ratio - Calibrated
85mV / kA@50Hz / 100mV / kA@50Hz
Ratio –Uncalibrated
110mV / kA@50Hz
Read Accuracy -
Calibrated
<0.5% (central position, 25℃)
Read Accuracy –
Uncalibrated
< 5% tolerance (central position, 25℃)
Maximum Current
Measurable
100kA
Coil Resistance
from 100 to 250 Ω
Position Error
±1% maximum
Phase error
≤0.5°
Shielded
00% coil, 100% output cable
Couplings
PA6 UL 94 V-O rated
Voltage Insulation
Coil: 3000V
Signal cable: 1000V
Compliance
LVD EN 61010-1:2010
EMC EN 61326-1:2013
Safety
1000V CATIII ,600V CATIV
Materials
Coil & cable: Thermoplastic rubber, flame retardant UL 94
V-0 rated
Lead Length
5 meters

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Operation
Temperature
-20℃to +70℃
-4°F to 158°F
Storage Temperature
-30℃to +90℃
-22°F to 194°F
Installation Type
Temporary or permanent installation
Warranty
12 months
Integrator
Modbus (RS485)
Integrator
Analogue (4-20mA)
Integrator
Output Signal
RS485
4-20mA
Amplitude Accuracy
25mA DC
Linearity
±0.2% (10% to 100% F.S.)
±0.2% (1% to 200% of range)
Bandwidth
30Hz to 5kHz
30Hz to 1kHz
Temperature Drift
50ppm/℃
200ppm/℃
Phase Error
≤0.5°
Power Supply
24V (0.5W or above)
24V (0.5W or above)
Size
114mm x 42mm x 29mm
4.5” x 1.7” x 1.1”
53mm x 38mm x 25mm
2.1” x 1.5” x 1.0”
Weight
20 grams
Materials
PC
Operation
Temperature
-20℃to +70℃
-4°F to 158°F
Storage Temperature
-30℃to +90℃
-22°F to 194°F

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Position Sensitivity
Dimensions
500 Amps
1,000 Amps
3,000 Amp
A
Windows size A
50 mm
105 mm
155 mm
B
Windows size B
60 mm
100 mm
150 mm
C
Coil Outer Diameter
66 mm
121 mm
171 mm
D
Coil section
8 mm
E
Lead Cable Total Length
5 meters
F
Coil length
200 mm
350 mm
510 mm
Conductor Position
Typical Error (%)
•Adjacent to the center of coil
0.2%
•Adjacent to the inside coil
＜1%
21 mm
0.8”
5 mm
0.2”
20 mm
0.8”
10 mm
0.4”

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Installation –Mechanical
WARNING! Risk of electrical shock.
Any contact with energised parts of the product, may lead to an electrical
shock which can lead to serious injuries or even death. The user shall take
all measures necessary to protect against electrical shock.
Notes
•Users should be suitably qualified, licensed and experienced to install, operate,
maintain and remove this product
•Before installing the product, make sure it is rated for your system (refer
to the “Specifications” section).
oUse of the product outside specified ranges or operating parameters can
lead to malfunctions and may damage the product or system.
•The system must be disconnected from any power supply during maintenance
work.
•When operating the Rogowski Coil, certain parts of the module may carry
hazardous live voltage (e.g. primary conductor). The user shall take all measures
necessary to protect against electrical shock. The Coil’s transducer is a built-in
device containing conducting parts that shall not be accessible after installation.
A protective enclosure or additional insulation barrier may be necessary.
•Do not use this product in explosive areas.
•Do not stress the coil by applying any kind of mechanical force (i.e. twisting,
puncturing, excessive pressure, tight bending, etc.) as this will dramatically
degrade the device’s accuracy.
•Do not disassemble the product.
•Please observe local and national regulations before/during installation and
operation.
•The product must be installed properly, otherwise it may lead to inaccurate
measurement values.
•Incorrect installation can damage the product, cause it to work incorrectly or
result in injury or death.

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Installation and maintenance shall be done with the main power supply disconnected
except if there are no hazardous live parts in or in close proximity to the system. Local
and national regulations must be fully observed.
Step 1 –Locate clip on the base unit
Step 2 –Unscrew clip and pull out coil from base unit
Step 3 –Place coil over conductor, ensuring arrow faces toward the load
Step 4 –Insert coil back into base unit and screw clip to secure the coil

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Installation –Electrical
WARNING! Risk of electrical shock
Incorrect wiring or contact with energised parts of the product, may lead to
an electrical shock which can lead to serious injuries or even death. The
user shall take all measures necessary to protect against electrical shock.
Notes:
•Always check the coloured wires to make sure they are wired correctly.
•Consider all local and national safety requirements and regulations for electrical
installations.
•The system must be disconnected from any power supply during
installation and maintenance work.
•Any electrical work on the system is only allowed by authorised and qualified
personal.
Rogowski Coil with
Modbus (RS485) Integrator
Rogowski Coil with
Analogue (4-20mA) Integrator
Red Wire
Power supply +24V DC
Power supply +24V DC
Blue Wire
Ground
Ground
Green Wire
A port of RS485 (Data +)
Signal ground
Yellow Wire
B port of RS485 (Data -)
4 to 20 mA signal

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Wiring - Modbus (RS485)
Rogowski Coil with
Modbus (RS485) Integrator
Red Wire
Power supply +24V DC
Blue Wire
Ground
Green Wire
A port of RS485 (Data +)
Yellow Wire
B port of RS485 (Data -)
Arrow points towards load
Modbus
Integrator
Red wire = +24V
DC
Blue wire = 0V DC
Green wire = Data + (A)
Yellow wire = Data - (B)
Load

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Wiring - Analogue (4-20mA)
Rogowski Coil with
Analogue (4-20mA) Integrator
Red Wire
Power supply +24V DC
Blue Wire
Ground
Green Wire
Signal ground
Yellow Wire
4 to 20 mA signal
Scaling
•4 mA = 0
•20 mA = 500, 1000 or 3000 depending on coil selection
Arrow points towards load
4-20mA
Integrator
Red wire = +24V
DC
Blue wire = 0V DC
Green wire = Signal ground)
Yellow wire = 4-20mA signal
Load

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Warranty
Compressed Air Alliance provides a 12-
month warranty for all Rogowski Coils.
The warranty covers materials and
workmanship under the stated
operating conditions from the date of
delivery. Please report any findings
immediately and within the warranty
time.
If faults occur during the warranty
period Compressed Air Alliance will
repair or replace the defective unit,
without charge for repair labour and
material costs but there is a charge for
other services such as labour to remove
or reinstall the instrument, transport
and packing. Warranty repairs do not
extend the period of warranty.
The following damage is excluded from
this warranty:
•Improper use and non-
adherence to the user manual.
•Use of unsuitable accessories.
•External influences (e.g. damage
caused by vibration, damage
during transportation, excess
heat or moisture).
The warranty is cancelled when one
of the following situations occurs:
•The user opens the
measurement instrument
without a direct request written
in this manual.
•Repairs or modifications are
undertaken by third parties or
unauthorised persons.
•The serial number has been
changed, damaged or removed.
Other claims, especially damage
occurring on the outside of the
instrument (eg dents, marks), are not
included unless responsibility is
legally binding.
Need help?
You can contact Compressed Air
Alliance via:
•Phone (Australia): 1300 558 526
•E-mail:
[e-mail]
•Website:
www.compressedairalliance.com

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Rogowski Coil with Integrator User Manual v1
Appendices
For Modbus Integrator
Appendix 1 –Modbus Communication Protocol
Appendix 2 - Configuring Modbus using Modbus Poll

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Appendix 1 –Modbus
Communication Protocol
The Modbus (RS485) integrator adopts the standard protocol - Modbus-RTU. Baud
rate of communication can change to 1200, 2400, 4800, 9600, etc. through
programming. Error detection: CRC16 (cyclic redundancy check).
Modbus RS485 Communication Settings
Parameters
Available Valves
Default Valves
Baud rate
1200
2400
4800
9600
19200
9600
Parity
Odd
Even
None
None
Data Bits
8
8
Stop Bits
1
1
Address
1 to 247
1
Request Instruction Format
Slave Address
Function Code
Command Block
CRC
8-Bits
8-Bits
N×8-Bits
16-Bits

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Functional Code
Functional code tells what function addressed terminal equipment can execute. The
following table lists the functional code that used by this instrument, as well as their
significance and function.
Function Code
Function Name
Behaviour
Decimal
Hexadecimal
3
03H
Read Holding
Registers
Read present HEX from one or
more
registers
16
10H
Write Multiple
Registers
Write present HEX on multiple
registers
Register Table
Register tables have the following columns:
Register
Alias
Register
Address
Action
R/WC
Size
Type
Units
Description
Register Alias: The meaning of the register
Register Address: Modbus address of register encoded in the Modbus frame, in
decimal (dec)
Action: The read/write by command register
Size: The data size in Int16
Type: The encoding data type
Units: The unit of the register value
Range: The permitted values for this variable, usually a subset of what the format
allows

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CRC check method
Redundant Cyclic Code (CRC) contains 2 bytes, i.e 16-bit binary. CRC code is
calculated by the sending device and placed at the end of the sending message. The
receiving device recalculates the received CRC code, compares whether the
calculated CRC code is consistent with the received one, and if the two do not
match, it indicates an error.
CRC code calculation method is first preset, 16-bit registers are all 1. Then step by
step every 8 bits of data information processing. Only 8 bit data, start bit and stop
bit are used in CRC code calculation, and if there is parity bit, parity bit is also
included but it does not participate in CRC code calculation.
At the time of calculating the CRC code, the 8-bit data is different from the register
data, and the result is one byte to the low position and fills the highest bit with 0.
Check the lowest bit again, if the lowest bit is 1, the contents of the register are
different from the preset number or, if the lowest bit is 0, no XOR operation is
carried out. This process has been repeated 8 times. After the eighth shift, the next
8 bits are different from the contents of the current register, and this process is
repeated 8 times as above. After all the data information is processed, the final
register is CRC code value. CRC data in the code send, receive when the low byte
before.
Compute the CRC code by:
1. Preset 16-bit register is hexadecimal FFFF (that is, all 1), which is called CRC
register.
2. The first 8-bit data is different from the low position of the 16-bit CRC register
and the result is placed in the CRC register.
3. Move the contents of the register to the right (low), fill the highest bit with 0,
check the lowest bit.
4. If the lowest position is 0: repeat step 3 (shift again).
oWhen the lowest bit is 1: CRC register is A001(10100000 with polynomial
0000 0001.
5. Repeat steps 3 and 4, eight times to the right. In this way, the entire 8-bit data is
processed.
6. Repeat steps 2 through 5 to process the next 8-bit data.
7. Final CRC register is the CRC code.

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List of data types
The following table lists the data types that this document may use:
Type
Description
Range
UInt8
8-bit unsigned integer
0 - 255
UInt16
16-bit unsigned integer
0 - 65535
Int16
16-bit signed integer
-32768 - +32767
UInt32
32-bit unsigned integer
0 - 4 294 967 295
UInt64
64-bit unsigned integer
0 - 18 446 744 073 709 551
615
UTF8
8-bit field
Multibyte character encoding
for Unicode
Float32
32-bit value
Standard representation IEEE
for floating number (with
single
precision)
Bitmap
-
-
Date Time
-
-
Definition description of data byte direction: Except for the CRC-16 check code at
the end of the instruction, the order of receiving and sending bytes is low bytes
before, and the order of receiving and sending bytes of all other data is high bytes
before.

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Function Code (3) Operating Instructions
Read device parameter instruction format:
No.
Alias
Type
Range
Description
1
Slave ID
UInt8
0 –127
Address 0 for point-to-point
communication only
2
Function Code
UInt8
3
3
Register Start
Address
UInt16
-
High byte before
4
Number of
Read Registers
UInt16
1 –127
High byte before
5
CRC-16
Verification
Code
UInt16
-
Low byte before
Return device parameter instruction format:
No.
Alias
Type
Range
Description
1
Slave ID
UInt8
0 –127
Address 0 for point-to-point
communication only
2
Function Code
UInt8
3
3
Data byte
length
UInt8
-
Number of registers*2
4
Register 1 data
UInt16
-
High byte before
5
….
UInt16
-
High byte before
6
Register 1 data
UInt16
-
High byte before
7
CRC-16
Verification
Code
UInt16
-
Low byte before