APG MNU Slave Sensor User Manual

Operator’s Manual

AUTOMATION

P R O D U C T S

GROUP, INC.

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • E-mail: [e-mail]

MNU

series

Ultrasonic Sensors

Rev. B1 5/13

MNU Series Ultrasonic Sensors Rev. B1, 5/13

2

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

Table of Contents

Warranty ........................................................................................ 3

Understanding Ultrasonics .......................................................... 4-5

Installa• on ................................................................................... 6-8

Wiring ............................................................................................. 9

Sensor Communica• ons .......................................................... 10-17

Parameter Descrip• ons ........................................................... 16-32

Web Alarming .......................................................................... 33-34

Inspec• on and Maintenance ........................................................ 35

Specifi ca• ons ................................................................................ 36

Dimensions ................................................................................... 37

Rev. B1, 5/13 MNU Series Ultrasonic Sensors

3

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

APG warrants its products to be free from defects of material and workmanship
and will, without charge, replace or repair any equipment found defec! ve
upon inspec! on at its factory, provided the equipment has been returned,
transporta! on prepaid, within 24 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 representa! on or warranty, express or implied, made by any sales
representa! ve, distributor, or other agent or representa! ve of APG which is
not specifi cally set forth herein shall be binding upon APG. APG shall not be
liable for any incidental or consequen! al damages, losses or expenses directly
or indirectly arising from the sale, handling, improper applica! on or use of the
goods or from any other cause rela! ng thereto and APG’s liability hereunder, in
any case, is expressly limited to the repair or replacement (at APG’s op! on) of
goods.

Warranty is specifi cally at the factory. Any on site service will be provided at
the sole expense of the Purchaser at standard fi eld service rates.

All associated equipment must be protected by properly rated electronic/
electrical protec! on devices. APG shall not be liable for any damage due
to improper engineering or installa! on by the purchaser or third par! es.
Proper installa! on, opera! on 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 Authoriza! on (RMA) number which must appear
on all related papers and the outside of the shipping carton. All returns are
subject to the fi nal review by APG. Returns are subject to restocking charges as
determined by APG’s “Credit Return Policy”.

• Warranty and Warranty Restric! ons

MNU Series Ultrasonic Sensors Rev. B1, 5/13

4

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

• Understanding Ultrasonics

Ultrasonic sensors use a transducer to transmit bursts of ultrasonic sound
waves. Each burst contains a series of pulsed sound waves that emit in the
shape of a cone, refl ect off the target, and are detected by the sensor. The # me

required for the sound waves to travel to and from the target is converted into
a distance measurement by the sensor. Ultrasonic sensing is aff ected by several
factors including the target surface, distance, size, and angle. The following
considera# ons will help ensure the best possible target condi# ons.

Surface

The ideal target surface is hard and smooth. This type of surface will refl ect a
greater amount of signal than a so$ or uneven surface. Sound wave absorbent
materials, such as granules and powders, will reduce the opera# ng range of the
sensor and decrease measurement accuracy.

Distance

Sound wave a% enua# on increases as the distance traveled increases.
Therefore, targets at longer ranges require be% er refl ec# ve characteris# cs than
targets that are closer to the sensor.

Size

A large object will have a greater surface area to refl ect the signal than a
smaller one. Therefore, a large target will be detected at a greater distance
than a small target. The surface area recognized as the target will generally be
the por# on closest to the sensor.

Rev. B1, 5/13 MNU Series Ultrasonic Sensors

5

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

Angle

The inclina! on of the object’s surface in rela! on to the sensor face will aff ect
the strength of the refl ected sound waves. Surfaces perpendicular to the
sensor will refl ect more signal directly back to the sensor. If a surface is more
than a few degrees off perpendicular, enough of the signal will be refl ected
away from the sensor that the target will not be detected. Generally speaking,
a target angle greater than 5 degrees off perpendicular will not be detected.
The target angle becomes increasingly cri! cal as the distance to the target
increases.

Environmental Condi! ons

Temperature, humidity, vapors, dust, and pressure can aff ect the sensor’s
performance. APG ultrasonic sensors are designed to compensate for many of
these condi! ons. However, if the condi! ons are extreme, sensor performance
can be degraded enough to require the use of a longer-range sensor than
normal condi! ons would require. Ultrasonic sensors may not be suitable for
applica! ons with heavy chemical vapors (such as solvents or gasoline), heavy
dust or when signifi cant surface foam is present.

MNU Series Ultrasonic Sensors Rev. B1, 5/13

6

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

NOTE: S! lling pipes are an excellent solu! on for liquid level
applica! ons where an unobstructed path to the target is not feasible
(see s! lling pipe moun! ng on page 9 for details).

• When moun! ng outdoors, it’s best to shade the sensor from direct
sunlight. Direct sunlight can warm the sensor housing above the ambient
temperature causing false temperature readings and overcompensa! on by
the sensor.

• Installa! on

Proper sensor moun! ng is cri! cal for successful opera! on of an ultrasonic
sensor. Using the following guidelines can help ensure trouble free installa! on
and opera! on:

• Ensure that the sensor face is perpendicular to the target surface. If the

target is more than a few degrees off perpendicular, it may not be
detected. Targets at greater distances will require more precise sensor
alignment.

• Mount the sensor in a loca! on that provides an unobstructed column

of air from the sensor to the target. The required width of the air
column depends on several factors, including the angle and refl ec! ve
characteris! cs of any poten! al targets on the edge of the column, the
sensi! vity se$ ng of the sensor, the maximum distance to the target, and
the refl ec! ve characteris! cs of the target itself. Generally speaking a 3 to 4
foot diameter unobstructed column is suffi cient even at longer ranges.

11.4

in

.

1

9

i

n

.

2

2

.

8

in

.

2

6

.6

in

.

30.

4

i

n

.

3

4

.

2

in

.

3

8

i

n

.

3

.

8

in

.

7

.

6

i

n

.

9

°

1

5

.

2

i

n

.

2

ft.

4

f

t

.

3

f

t

.

5

f

t

.

6

f

t

.

7ft

.

8

f

t

.

9

f

t

.

1

0

f

t

.

1

f

t.

dLJƉŝĐĂůďĞĂŵƐƉƌĞĂĚŽĨĂƐĞŶƐŽƌŽƉĞƌĂƟŶŐĂƚŵĂdžŝŵƵŵƐĞŶƐŝƟǀŝƚLJ

Rev. B1, 5/13 MNU Series Ultrasonic Sensors

7

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

• Always mount above the highest an! cipated target level by at least the

published minimum blanking distance. If a target enters into the blanking
area, error in the detec! on will occur. It is always advisable to allow for

suffi cient headroom to ensure that the target does not enter the blanking
area.

• Generally it is advisable to mount the sensor away from any vessel fi ll
spouts. However, if heavy foam is expected, it is o$ en helpful to mount the
Sensor near a fi ll spout where the foam is being dispersed.

• Avoid moun! ng the sensor in the direct center of a tank with a signifi cantly
domed top. A domed top can act as parabolic dish, amplifying small
undesired signals that may be present inside the tank.

• Avoid moun! ng the sensor in close proximity to tank walls, especially on
tanks with corrugated walls or in applica! ons where product buildup on
the tank walls may occur.

>Žǁ^ĞŶƐŝƟǀŝƚLJĞƚĞĐƟŽŶƌĞĂ,ŝŐŚ^ĞŶƐŝƟǀŝƚLJĞƚĞĐƟŽŶƌĞĂ

MNU Series Ultrasonic Sensors Rev. B1, 5/13

8

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

Stand Pipe Moun! ng

Stand pipes are used to provide headroom at
the top of a tank when the target is expected
to come closer to the sensor than the
minimum blanking distance. It’s very cri! cal
that the stand pipe be installed perpendicular
to the target. This is especially important
on longer range applica! ons. The pipe must
have smooth walls (no joints) and no burs or
obstruc! ons. If possible, cut the end of the
pipe at a 10°-45° angle (see drawing). Use
the largest diameter pipe and shortest length
possible. As a general rule, the diameter of
the pipe should be 1/2 the length. The pipe
ID must remain the same through it’s en! re
length.

S! lling Pipe Moun! ng

S! lling pipes provide access to diffi cult areas
and help eliminate problems with foam.
The pipe must have smooth walls (no burs
or joints). Because the sound waves will
concentrate and propagate down the inside
walls of the tube, any irregulari! es on the
tube walls may produce echo returns and
cause false readings. S! lling pipes are limited
to liquid targets that will not leave heavy
deposits on the tube walls. Because the
sound waves are confi ned inside the pipe,
it is usually necessary to greatly reduce the
sensors sensi! vity and pulses se$ ngs. A vent

hole must be provided at the top of the pipe.
Be sure to keep the vent hole inside of the
blanking area.

Cut at angle

when possible

Vent Hole

Rev. B1, 5/13 MNU Series Ultrasonic Sensors

9

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

• Wiring

Always use shielded cable. It is recommended that twisted-pair cable be used
between sensors when connec! ng mul! ple sensors to the Modbus network.

NOTE:

Always use a high quality power supply that will deliver clean, stable

voltage.

The MNU series sensors are wired in a daisy-chain confi gura! on, as shown

below. Each sensor should be connected individually and assigned a unique
address before wiring the sensor into the Modbus network.

Power
Supply

Master
Device

RS-485 A

RS-485 B

Vdc

Vdc

+

-

Sensor 1

V+ V- A B

Sensor 2

V+ V- A B

Sensor 3

V+ V- A B

Use Shielded Cable

120 Ohm
Terminating
Resistor

120 Ohm
Terminating
Resistor

Modbus Daisy-Chain Wiring

Mirco Connector:
Pin 1 (Brown) +24 VDC
Pin 2 (White) RS-485 A
Pin 3 (Blue) DC Common
Pin 4 (Black) RS-485 B

4-Conductor Cable:
Red +24 VDC
Black DC Common
White RS-485 A
Green RS-485 B

MNU Series Ultrasonic Sensors Rev. B1, 5/13

10

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

• Sensor Communica! ons

The MNU sensor u! lizes standard Modbus RTU protocol (RS-485). The MNU
sensor can only operate as a slave device. For more informa! on about Modbus
RTU, please visit www.modbus.org.

The MNU sensor will transmit at (allow a minimum delay of 300 ms between
transac! ons):

9600 bps
8 data bits
No parity
1 stop bit

Input Registers (0x04):

Register Returned Data

30300 Raw Distance/Level Reading (in mm, unsigned)
30302 Temperature Reading (in

0

C, signed)

30303-30304 Calculated Reading (in selected units, without decimal place)

NOTE: the Calculated Reading will be returned as a whole number. In order

to a" ain the true result, the Decimal Place se# ng must be taken into ac­count. Refer to Decimal Place se# ng on page 21 for more informa! on.

Holding Registers (0x03):

Register Func! on Value Range

40400 Device Address 1 to 255

40401 Units 1 to 3

40402 Applica! on Type 0-10

40403 Volume Units 0 to 6

40404 Decimal Place 0 to 3

40405 Max Distance 0 to 10364 mm

40406 Full Distance 0 to 10364 mm

40407 Empty Distance 0 to 10364 mm

Rev. B1, 5/13 MNU Series Ultrasonic Sensors

11

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

(con! nued)

Register Func! on Value Range

40408 Sensi! vity 0 to 100

40409 Pulses 0 to 20

40410 Blanking 0 to 10364 mm

40411 Gain Control 0 to 4

40412 Averaging 0 to 100

40413 Filter Window 0 to 10364 mm

40414 Out of Range Samples 0 to 255

40415 Sample Rate 50 to 1000 msec.

40416 Mul! plier 1 to 1999

40417 Off set +/- 10364 mm

40418-40419 reserved n/a

40420 Temperature Compensa! on 0 = off , 1 = on

40421-40435 reserved n/a

40436-40437 Parameter 1 Data 0 to 100,000 mm

40438-40439 Parameter 2 Data 0 to 100,000 mm

40440-40441 Parameter 3 Data 0 to 100,000 mm

40442-40443 Parameter 4 Data 0 to 100,000 mm

40444-40445 Parameter 5 Data 0 to 100,000 mm

MNU Series Ultrasonic Sensors Rev. B1, 5/13

12

Automa! on Products Group, Inc.

APG...Providing tailored solu• ons for measurement applica• ons

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

Confi guring So# ware Communica! ons

Step 2: select “MNU” from the Sensor Type menu, then click the “Save

Confi g” bu" on at the bo" om of the screen.

Step 1: select “Communica# on” from the “Confi gure” menu.