APG warrants its products to be free from defects of material and workmanship
and will, without charge, replace or repair any equipment found defective upon
inspection at its factory, provided the equipment has been returned,
transportation prepaid, within 18 months from date of shipment from factory.
THE FOREGOING WARRANTY IS IN LIEU OF AND EXCLUDES ALL OTHER
WARRANTIES NOT EXPRESSLY SET FORTH HEREIN, WHETHER
EXPRESSED OR IMPLIED BY OPERATION OF LAW OR OTHERWISE
INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
No representation or warranty, express or implied, made by any sales
representative, distributor, or other agent or representative of APG which is not
specifically set forth herein shall be binding upon APG. APG shall not be liable
for any incidental or consequential damages, losses or expenses directly or
indirectly arising from the sale, handling, improper application or use of the
goods or from any other cause relating thereto and APG’s liability hereunder, in
any case, is expressly limited to the repair or replacement (at APG’s option) of
goods.
Warranty is specifically at the factory. Any on site service will be provided at
the sole expense of the Purchaser at standard field service rates.
All associated equipment must be protected by properly rated electronic/
electrical protection devices. APG shall not be liable for any damage due to
improper engineering or installation by the purchaser or third parties. Proper
installation, operation and maintenance of the product becomes the
responsibility of the user upon receipt of the product.
Returns and allowances must be authorized by APG in advance. APG will
assign a Return Material Authorization (RMA) number which must appear on
all related papers and the outside of the shipping carton. All returns are subject
to the final review by APG. Returns are subject to restocking charges as
determined by APG’s “Credit Return Policy”.
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APG...Providing tailored solutions for measurement applications
Ultrasonic sensors measure distance by using a transducer to send out ultrasonic bursts. Each burst contains a series of pulsed sound waves. The ultrasonic burst emits in the shape of a cone, reflects off the detected target, and is
received by the transducer. The time required for this burst to travel to and from
the target is measured and converted into a distance measurement by the sensor.
Ultrasonic sensing is affected by several factors including the target’s surface,
size, angle and the distance from the sensor. Environmental conditions such as
temperature, humidity, gases, and pressure may also affect the measurement.
APG sensors automatically compensate for most of these varied environments.
The following considerations will help ensure the best possible sensing conditions.
SURFACE
The ideal target surface is hard and smooth. This surface will reflect a greater
amount of signal than a soft, rough surface. A weak echo, which is the result of
a small or soft object, will reduce the operating distance of the sensor and
decrease its accuracy.
DISTANCE
The shorter the distance from the sensor to an object, the stronger the returning
echo will be. Therefore, as the distance increases, the object requires better
reflective characteristics to return a sufficient echo.
SIZE
A large object will have more surface to reflect the signal than a small one. The
surface area recognized as the target is generally the portion closest to the
sensor.
ANGLE
The inclination of the objects’ surface facing the ultrasonic sensor affects the
reflectivity of the object. The portion perpendicular to the sensor returns the
echo. If the entire surface is at a great enough angle, the signal will be reflected
away from the sensor and no echo will be detected.
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The IRU-2xx4/3xx4 is a low cost ultrasonic sensor used for non-contact measurement over a 1’ to 35’ range. RS-485 interface allows for convenient sensor
communication. The sensor is encased in a sealed chemical resistant housing
and has built in temperature compensation.
SPECIFICATIONS
IRU-2xx4IRU-3xx4
Range:1’ to 25’1.25’ to 35’
Housing:ABS or PVCPVC
Outputs:RS-485 & NPNRS-485 & NPN
Supply Voltage:12 to 28 VDC12 to 28 VDC
(24 VDC Recommended sensor performance
is diminished if lower voltage applied)
Current Draw:60 ma @ 24 VDC60ma @ 24VDC
2.0 Watts Max.2.0 Watts Max.
Transducer TypeCeramicCeramic
RatingsNEMA 4XNEMA 4X
Sensor adjust RS-485 interfaceRS-485 interface
Operating temp.-40 to 60 °C-40 to 60 °C
Resolution.1inches (2.5mm).1inches (2.5mm)
Accuracy+/- 0.25% Range+/- 0.25% Range
Temp. Comp.InternalInternal
(thermistor located on transducer face)
Sample RateProgrammable, 1 to 22 Hz
Beam pattern9 degrees off axis (when operating with
high sensitivity)
Cable6 conductor, 22 gauge 6’ length
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APG...Providing tailored solutions for measurement applications
A command must be sent to the sensor in order to obtain any information from
the unit.
•All distances coming form the sensor will be in whole millimeters.
•The temperature is returned as a Celsius value with a 40° positive offset
•No negative numbers, decimal numbers or fractions are sent.
COMMAND STRUCTURE
All of the IRU-2XX4/3XX4 commands follow the format below.
Messages from the sensor
Start character(AAh)
Sensor Numberas single byte value
Command Numberas single byte value
Data valuesas double byte value
Stop character(55h)
6 bytes Total
Messages from the sensor
Start character(66h)
Sensor Numberas single byte value
Command Numberas single byte value
Data value 0as double byte value
Data value 1as single byte value for returning distance and
temperature if possible
Stop character(99h)
7 bytes total
MEMORY
There are two types of memory available in the IRU-2XX4/3XX4, E2 and RAM.
E2 is nonvolatile and will retain the data if power to the sensor is lost or turned
off. RAM is volatile and will not be retained without power. The number of
WRITES available to E2 is approximately 10,000. Prudent use of this function
will allow a lifetime of use. The number of READS from E2 is unlimited. If
frequent parameter changes are anticipated or necessary, use the WRITE RAM
functions to avoid “wearing out” the E2 memory.
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COMMAND
01h)Read Sensor Number EE
02h)Write Sensor Number EE
03H)READ BANK NUMBER EE
04H)WRITE BANK NUMBER EE
05H)READ BLANKING EE
06H)WRITE BLANKING EE
07H)READ PULSES EE
08H)WRITE PULSES EE
09H)READ SENSITIVITY EE
0AH)WRITE SENSITIVITY EE
0BH)READ CALIBRATION EE
0CH)WRITE CALIBRATION EE
0DH)READ TEMPERATURE COMPENSATION
0EH)WRITE TEMPERATURE COMPENSATION
0FH)READ AVERAGE EE
10H)WRITE AVERAGE EE
11H)READ OUT OF RANGE SPAN EE
12H)WRITE OUT OF RANGE SPAN EE
13H)READ OUT OF RANGE COUNT EE
14H)WRITE OUT OF RANGE COUNT EE
15H)READ SAMPLE RATE EE
16H)WRITE SAMPLE RATE EE
17H)READ TRIP BEGIN
18H)WRITE TRIP BEGIN
19H)READ TRIP END
1AH)WRITE TRIP END
1BH)READ TRIP TYPE
1CH)WRITE TRIP TYPE
1DH)READ TRANSMIT OFF(0)/ON(1)
1EH)WRITE TRANSMIT OFF(0)/ON(1)
1FH)RESET PARAMETERS TO DEFAULTS
20H)START TRANSMIT SENSOR
21H)STOP TRANSMIT SENSOR
22H)START TRANSMIT BANK
23H)STOP TRANSMIT BANK
24H)DISTANCE AND TEMPERATURE READ
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The Parameters (E) command displays the current settings of the sensor. The
following is an example of a parameter report from the IRU-2XX4/3XX4.
PARAMETERS MENUMin.Max.
Distance Sensor Number EE09
Bank Number EE09
Blanking EE1527620
Pulses EE020
Sensitivity EE0100
Calibration EE01001999 (0 .100 to 1.999)
Temp. Compensation01
Average EE110
Out of Range Span EE07620
Out of Range Count EE0250
Sample Rate EE231000
Trip point begin07620
Trip point end07620
Trip point type07
Sensor Transmit01 (0 = OFF, 1 = ON)
The IRU-2XX4/3XX4 will display the distance to a target in millimeters.
DISTANCE SENSOR
To request the Distance and temperature from sensor number 1, send:
Up to 10 sensors may be attached to the same communication and power line.
Each sensor is then assigned a unique number. Each sensor must have a uniqueSensor Number. Sensor Numbers are assigned one at a time as the sensors are
placed on line. When assigning these values, ensure that only the desired sensor
is connected to the RS-485 line.
With only one sensor connected to the RS-485 communication lines, assign a
sensor number to a sensor by using the following steps.
1. Determine the present sensor number by reading the sensor number:
There are 10 banks (0-9) available for sensor assignment and up to 10 sensors
may be assigned to any 1 bank. However, this system will support a maximum of
10 sensors and each sensor must have a unique Sensor Number. Banks allow a
number of sensors to be controlled simultaneously.
Assign a Bank Number by,
Send
AAhStart Byte
01h,Sensor Number
03hCommand
02hDataBank number 2
00hData (not used)
55hEnd Byte
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Blanking allows the sensor to ignore all echoes returned before this distance.
There is a minimum distance to which this can be set which is 152 millimeters.
This distance (or time) allows the ceramic in the transducer to stop vibrating after
it has transmitted a series of pules.
To read the current setting for the blanking in the sensor:
Example: Suppose the sensor is mounted in a position that were a partial
structure is located 600 mm from the sensor head. The desired detection range
is from 650 mm to 2100 mm . Setting the blanking at 620mm would allow the
sensor to ignore the structure and monitor the desired detection area.
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Sensitivity controls the gain of the receive circuit. High values will amplify the
return pulse enabling the sensor to detect weak signals. Caution: High sensitivity setting increases the chance for the sensor to detect unwanted objects, which
can decrease the reliability of the output.
To read the Sensitivity in a sensor, use the command structure:
Calibration The IRU-2XX4/3XX4 must be calibrated if a familiar reading is
desired. The software is designed so that a calibration factor of 1000 will yield
units that represent inches, feet and meters. Variations of the speed of sound in
different atmospheres may yield readings which slightly differ from actual
measured values. If this is unacceptable, vary the Calibration factor to “dial in”
the exact number desired.
Acceptable values for this parameter range from 0100 to 1999
If a certain distance to a target is known and the sensor is not outputting the
desired reading, use the following formula to obtain the desired reading.
New Calibration Factor = (Desired Distance Reading x Old Calibration Factor) /
Sensor Distance Reading.
Example: Suppose a target is 5.50 feet from the face of the sensor. The sensor
has a calibration factor of 1000 and is yields a Distance Reading of 5.65 ft.
Calculate the new Calibration Factor by:
New Calibration Factor = (5.50 x 1000) / 5.65 = 0973.
To read the calibration factor in a sensor, use the command structure:
Temperature Compensation allows the operator to enable or disable tempera-
ture compensation. When this feature is enabled, the IRU-2XX4/3XX4 will make
adjustments for variations in temperature, which affects the speed of sound. This
will produce a more exact output.
To Read the Temperature Compensation in a sensor, use the command structure:
Average: The sensor will average the number of samples set in the Average
Parameter. Each qualified sample is placed into a buffer and averaged with the
previous samples to generate a steady output. A qualified sample is one that falls
within the boundaries set in the Out of Range Span Parameter.
To Read the number of samples being averaged in a sensor, use the command
structure:
Out of Range Span The Out of Range Span was designed to eliminate extrane-
ous signals and noise. This Span or window changes with the distance of the
average distance reading. This window will allow only readings that fall within
its limits. If the target is suddenly changed outside of the window limits, the
sensor will wait until a number or echoes specified in the Out of Range Count
are received within a new window before updating the output reading.
To Read the Out of Range Span in a sensor, use the command structure:
Out Range Count : indicates the number of consecutive samples outside the
Out of Range Span that would need to be detected before the sensor recognizes
them as legitimate samples. For example, with the Out of Range Span set at
300mm, the sensor detecting a distance at 1,520mm and the OUT OF RANGE
COUNT set to 10, and a target entered the detection area of the sensor at a
distance less than 1,220mm or greater than 1,820mm, the target would need to be
present long enough for the sensor to receive 10 samples before the sensor would
recognize the target. If the target were in the detection area of the sensor for only
9 samples, the sensor would retain the 1,520mm distance reading.
To Read the Out of Range Count in a sensor, use the command structure:
SendReceive
AAhStart Byte66hStart Byte
01h,Sensor Number01hSensor Number
13hCommand13hCommand
00hData (not used)##hOut of range (High Byte)
00hData (not used)##hNA (Low Byte)
55hEnd Byte##hNA
99hStop Byte
To change the Out of Range Count to 10 in the sensor, use the command
structure;
18
Send
AAhStart Byte
01h,Sensor Number
14hCommand
0AhData10 decimal = A hex
00hData (not used)
55hEnd Byte
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The IRU-2XX4/3XX4 has a programmable NPN trip point that is fully programmable for ‘BEGIN’ and ‘END’ points and ‘TYPE’ of operation. ( see page 20) The
zero point of distance will be at the transducer, the relay trip points is programmed in millimeters.
DESCRIPTIONPARAMETERSEXPLANATION
Begin TripUnits = millimetersSets the begin point
Default =of Trip
End TripUnits = millimetersSets the end point
Default =of Trip
Trip TypeRange = 0 - 7Selects the type of
0 - nearfunction Trip will
1 - exclusiveperform. (See Page 20)
2 - hysteresis near
3 - far
4 - inclusive
5 - hysteresis far
6 - disable
Default = 0
To read the Begin Trip Distance in sensor number 1 , use the command structure:
The IRU-2XX4/3XX4 can operate in two different modes:
(0) Control mode were the sensor will begin and end transmitting when it receives
a begin or end transmit or bank command.
(1) Continuous transmit mode were the sensor will transmit as long as it has
power.
To read the mode the sensor number 1 is operating in, use the command structure:
Stop Transmit Sensor allows the user to identify a sensor and have it start
transmitting. This command controls a single sensor.
To have sensor number 1 stop transmitting, use the command structure;
Send
AAhStart Byte
01h,Sensor Number
21hCommand
01hNA
00hNA
55hEnd Byte
START TRANSMIT BANK
Start Transmit Bank allows the user to identify a bank of sensors and have
them start transmitting. This command controls up to 10 sensors providing they
are all assigned to the same bank.
To have Bank number 1 begin transmitting, use the command structure;
Stop Transmit Bank (e) allows the user to identify a bank of sensors and have
them stop transmitting. This command controls up to 10 sensors providing they
are all assigned to the same bank.
To have Bank number 1 stop transmitting, use the command structure;
Send
AAhStart Byte
00h,NA
23hCommand
01hBank Number
00hNA
55hEnd Byte
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Reset allows the user to reset the parameters in a particular sensor to the factory
defaults.
To reset the parameters in sensor number 1, use the command structure:
Send
AAhStart Byte
01h,Sensor Number
1FhCommand
00hNA
00hNA
55hEnd Byte
MOUNTING
When mounting any ultrasonic sensor, alignment is critical. Ensure the face of
the transducer is parallel to the target. A misalignment of a few degrees can
affect the accuracy and reliability of the sensor.
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