HK INSTRUMENTS AVT Air Velocity Transmittera User Guide

Safety Precautions
- Before using the AVT air velocity transmitter, ensure to read and understand all safety precautions mentioned in the user manual.
Description of the Product
- The AVT air velocity transmitters are designed for measuring air velocity and temperature in ventilation ducts in commercial settings. They are specifically compatible with dry air and should not be used with flammable or corrosive gases.
Commissioning
- Mounting the Product: Follow the instructions provided to securely mount the transmitter in the desired location within the ventilation duct.
- Wiring: Connect the transmitter as per the wiring diagram provided in the user manual to ensure proper functionality.

Maintenance
- Cleaning the Probe and the Sensor Element: Regularly clean the probe and sensor element of the transmitter to maintain accurate readings. Use a soft cloth or brush to gently clean these components.

Modbus
- Input Registers: Refer to the user manual for details on configuring input registers for specific applications.
- Holding Registers: Understand how to set and use holding registers for data storage and retrieval purposes.
Disposal
- When disposing of the AVT air velocity transmitter, follow local regulations for electronic waste disposal to minimize environmental impact.

FAQs

Q: Can the AVT air velocity transmitter be used with corrosive gases?
- A: No, the AVT air velocity transmitter is not intended for use with corrosive gases. It is only compatible with dry air.
Q: What industry are the AVT air velocity transmitters designed for?
- A: The transmitters are designed for use in the HVAC/R industry and are intended to be connected to building automation systems.

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AVT air velocity transmitter
USER GUIDE

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Introduction

Thank you for choosing an AVT air velocity transmier. It is an air velocity and temperature transmier. The -MOD models have Modbus communicaon instead of analogue outputs. Other models have one analogue air velocity output and one analogue temperature output. You can select the measurement range and the output mode for the analogue outputs during commissioning. The -D models have a display that shows air velocity and temperature measurement values. The -MOD models have an RS-485 connecon for Modbus RTU communicaon. The -R model includes a relay and a relay connector. You can configure the device sengs using: · the device menu (-D models) · Modbus communicaon (-MOD models)
1.1 About this user guide
This user guide contains important informaon about the installaon, wiring, configuraon and use of the product. Read this guide carefully before you install the product, connect the wires, or operate the product. Make sure that you fully understand all instrucons before you start work. If you are not sure what the instrucons mean, contact the seller or the manufacturer. Follow all instrucons in this user guide carefully. Always obey the applicable local rules and regulaons. The original instrucons were wrien in English. If there are differences between the English instrucons and the translaons, refer to the English instrucons. If you find a mistake in the English instrucons or in the translaons, please send the details to the manufacturer.
1.2 Intended use
The AVT air velocity transmiers are intended to be used in commercial environments for measuring air velocity and temperature in venlaon ducts. They are compable with dry air. The AVT air velocity transmiers are not intended to be used with flammable or corrosive gases. These transmiers are intended to be connected to building automaon systems in the HVAC/R industry.

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Safety precautions

The product is developed, manufactured and tested according to high quality standards. However, instrucons for safe use must be followed when installing, using or disposing the product or parts of product.
Read this user guide carefully before you commission, use or service this device. To avoid any kind of damage to people or property, follow the instrucons carefully. HK Instruments is not liable for any hazards, injury to people, or damage to property caused by incorrect installaon or misuse of the device.
To avoid electrical shock or damage to equipment, disconnect power before you install or service the product. Use only proper wiring that is rated for the full operang voltage and maximum current in the system. The wiring must also withstand fault condions.
To avoid fire and/or explosion, do not use the product in potenally flammable or explosive atmosphere.
Make sure that the product is not damaged before installaon. Do not drop the product or use excessive force during installaon. Do not use the product if you can see any damages.
Aer installaon, the product will be part of a system whose specificaons and performance characteriscs are not designed or controlled by HK Instruments. Refer to naonal and local authories to ensure that the installaon is funconal and safe.
The product should only be used in professionally designed applicaons. Unauthorised modificaons are not allowed. The product must not be used in relaon with any equipment that in case of a failure may threaten, directly or indirectly, human health or life or result in danger to human beings, animals or property.
In this document, there are different warnings and notes. The warning and note types are defined in the following table.

Sign

WARNING:

CAUTION:

Important:

Description The warning symbol indicates a potenally hazardous situaon which, if not avoided, could result in death or serious injury.
The cauon symbol indicates a potenally hazardous situaon which, if not avoided, could result in minor or moderate injury.
The important symbol indicates a potenally hazardous situaon which, if not avoided, could result in damage to the device or property.

Note:

The note symbol indicates a useful p or a recommended way to complete a task. These notes also provide informaon that is useful but not crical to the user.

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Description of the product

This secon introduces the main parts of the product and contains the technical specificaons.
3.1 Main components

9 10

3
4
1 Display (-D models) 3 Cable gland 5 Cover locking screw (-R models) 7 Probe 9 Probe locking screw 11 Holes for fixing screws

2 Cover 4 Strain relief 6 Duct flange 8 Sensor element 10 Housing

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Tout/B

Vout/A 24V

NC COM

GND

Tout/B

Vout/A

24V GND

12 Menu buons (-D models)
14 Jumper for air velocity output signal selecon (excluding -MOD models)
16 Relay (-R models)
18 Modbus terminaon jumper (-MOD models)

13 Jumper for temperature output signal selecon (excluding -MOD models)
15 Terminal block
17 Measurement range selecon jumpers (excluding -D models)
19 Relay connector (-R models)

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3.2 Technical specifications
Property Supply Current consumpon Relay (-R models) Air velocity measurement
Measurement range Accuracy (typ. at 25 °C)
Temperature measurement Measurement range Accuracy (25 °C)
Warm-up me Outputs
Output signal 1 (T out [C])
Output signal 2 (v out [m/s])
Accuracy
Relay output (-R models)
Communicaon (MOD models) Display (-D models)
Operang condions Temperature
Humidity IP protecon class Wire Cable gland

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Value 24 Vac/dc ± 10 % max. 80 mA + 40 mA with mA output + 10 mA with relay opon (DC supply voltage) 250 Vac, 6 A res., adjustable operang direcon, switching point and hysteresis
0…2 m/s, 0…10 m/s, 0…20 m/s, freely selectable v 0.15 m/s and 2 m/s (0.2 m/s + 2 % from reading) v > 2 m/s and 10 m/s (0.5 m/s + 3 % from reading) v > 10 m/s (1.0 m/s + 3 % from reading)
-25…50 °C (probe) ±0.5 °C (air velocity > 0.5 m/s) 15 seconds
0…10 Vdc, load > 1 k 4…20 mA, load 20…400 0…10 Vdc, load > 1 k 4…20 mA, load 20…400 Vout: ± 0.025 V at 25 °C Iout: typically ±0.04 mA at 25 °C, load 100 max. ± 0.1 mA at 25 °C, load 20…400 3-screw terminal block (NC, COM, NO), potenal free SPDT 30 Vdc, 6 A / 230 Vac, 6 A res. (IEC 60664-1 OVC II) Modbus RTU 2-line display (12 characters/line), 46.0 x 14.5 mm Line 1: velocity / Line 2: temperature (default) Line 1: direcon of control output (oponal) Line 2: relay status (oponal)
-25…50 °C (probe) 0…50 °C (transmier housing) 0…95 %rH (non-condensing) IP54, cable downwards / -R and -MOD models: IP54, cables downwards and cables in both cable glands 0.2…1.5 mm2 (24…16 AWG) M16 (2 x M16: -R and -MOD models)

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Property Mounng
Materials Housing Cover Probe Duct flange
Dimensions (w x h x d)
Weight Storage temperature Conformance EMC RoHS WEEE LVD
3.3 Dimensions

Value with a duct flange, probe immersion length adjustable: 50…80 mm (probe length 100 mm) 50…180 mm (probe length 200 mm) 50…380 mm (probe length 400 mm)
ABS plasc PC plasc Stainless steel (AISI 304) LLPDP 86 x 95 x 168 mm (probe length 100 mm) 86 x 95 x 268 mm (probe length 200 mm) 86 x 95 x 468 mm (probe length 400 mm) 220 g -20…70 °C CE 2014/30/EU 2011/65/EU + (EU) 2015/863 2012/19/EU 2014/35/EU

UKCA S.I. 2016 No. 1091 S.I. 2012 No. 3032 S.I. 2013 No. 3113 S.I. 2016 No. 1101

All dimensions are in millimeters (mm).

71.5

168 / 268 / 468

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Duct flange dimensions

69 50 10

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Commissioning

4.1 Setting the jumpers
Note: Set the jumpers in the correct posion before you connect the supply voltage to the device.

4.1.1 Selecting the measurement range

There are different methods for selecng the measurement range. The method used depends on the device opons: · Devices that do not have a display: Select the measurement range by installing jumpers as shown in the table below. · Models with display (-D): Select the output signal mode with jumpers and then the measurement range via the
device menu. See secon Selecng the output mode on page 9
Selecting the measurement range with jumpers
Install the jumpers according to the table below to select the measurement range for devices that do not have a display.

J1 Tout/B

J2 Vout/A

mA V mA V

24V GND

J1 J2 * factory seng

0…2 m/s

4.1.2 Selecting the output mode

*0…10 m/s

0…20 m/s

Models with analogue outputs have two jumpers for output signal mode selecon on the circuit board. Select the voltage (0…10 V) or the current (4…20 mA) output signal mode based on the system requirements. The current output is not scalable. The voltage output is scalable.
You can configure the output signal separately for air velocity and temperature. Set the jumpers in the correct posion to select the output signal mode (V/mA) for air velocity and temperature.
See the table below for the jumper sengs.

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Tout
mA V
Vout
mA V

Output

Temperature output Air velocity output

Tout Vout

* factory seng
4.1.3 Terminating Modbus

Output signal mode: *Output signal

current (mA)

mode: voltage (V)

Output signal mode: *Output signal

current (mA)

mode: voltage (V)

Output signal mode: Output signal mode:

current (mA)

voltage (V)

Output signal mode: Output signal mode:

voltage (V)

current (mA)

Insert the terminaon jumper in the last device of the network to terminate the Modbus network. 1. Disconnect the device supply voltage. 2. Open the cover. 3. Insert the terminaon jumper in posion.

Tout/B

Vout/A

24V

GND

A. Terminaon jumper 4. Close the cover.
4.2 Mounting the product

WARNING: Handle the product with care. Dropping the product may cause internal damage and unwanted funcons in the connected system. CAUTION: Place the product outside the reach of children and animals.
Important: The product may only be installed in a locaon where the ambient condions meet the operang condion requirements. Note: Remove the device from the air duct before cleaning the duct.

Operang condions Temperature
Humidity

-25…50 °C (probe) 0…50 °C (transmier housing) 0…95 %rH (non-condensing)

1. Check that the product is not damaged during transportaon.

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2. Select the mounng posion on a straight duct.
Measure the length of the straight duct to make sure that the probe is posioned correctly. See the figure below for the required minimum length of straight duct.

· Round ducts: · D = duct diameter
· Rectangular ducts: · If there is a horizontal curve or a change in the duct size: D = width of the duct · If there is a vercal curve or a change in the duct size: D = height of the duct
3. Use the duct flange as a template and mark the screw holes and the probe hole on the duct. 4. Drill the screw holes and the probe hole on the duct.
The maximum screw diameter is 4 mm. The probe diameter is 10 mm. 5. Mount the duct flange on the duct with screws.
6. Push the transmier probe into the duct through the hole on the flange. Make sure that the cable glands of the transmier point down. See the figure below for the correct mounng orientaon.

A. Air flow direcon
Copyright HK Instruments 2024

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7. Adjust the probe to the correct depth. Make sure that the sensor element is in the middle of the duct.

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8. Tighten the locking screw on the duct flange to hold the probe in posion.
4.3 Wiring
WARNING: Device wiring and commissioning can only be carried out by qualified professionals. Always make the device wirings in de-energised electricity network. WARNING: Fuse at load supply (normally 6 A, 10 A, 16 A) does not always limit the relay output load current to 6 A. The relay maximum load is 250 Vac, 6 A res. WARNING: Add an external fuse to relay common connector. Use a me-lag fuse (max 6 A) that is in accordance with the standard IEC 60127-2. The product does not have an internal fuse for the relays. CAUTION: The product may only be connected to overvoltage category II electricity network according to IEC 60664-1. CAUTION: Use single stranded wires or use wire end sleeves if mul stranded wires are used.
Important: For CE and UKCA compliance, a properly grounded shielding cable is required.
The relay models (-R) and the Modbus (-MOD) models have two cable glands (the le and the right cable gland). Other models only have one cable gland (the le cable gland). See secon Wiring for Modbus models (-MOD) on page 13 for Modbus model wiring instrucons. 1. Open the cover.
WARNING: Do not open the device cover when the relay mains supply voltage is connected. Always do the commissioning of the device in de-energised relay electricity network. 2. Unscrew the strain relief on the le cable gland and route the cables for power in and signal out through the cable gland. 3. For relay models (-R), unscrew the strain relief on the right cable gland and route the cable for the relay through the cable gland.

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4. Connect the wires according to the table below.

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Tout/B Vout/A
24V GND

NC COM NO

Tout/B
Vout/A
24V GND NC COM NO

Temperature measurement output signal: 0…10 Vdc, load > 1 k 4…20 mA, load 20…400 Air velocity measurement output signal: 0…10 Vdc, load > 1 k 4…20 mA, load 20…400 24 Vac/dc supply 0 V
Relay output on -R models: 30 Vdc, 6 A / 230 Vac, 6 A res.

The nominal wiring terminal screw ghtening torque is 0.4 Nm. Important: Do not use excessive force when you ghten the wiring terminal screws.

5. Tighten the strain reliefs.
4.3.1 Wiring for Modbus models (-MOD)

Note: The -MOD models have Modbus communicaon instead of analogue outputs.

Important: For CE and UKCA compliance, a properly grounded shielding cable is required.

It is recommended to use shielded twisted pair cable for Modbus cabling. The cable shield must be earthed only in one point, usually at the end of the main cable.
1. Open the cover. 2. Unscrew the strain relief on the le cable gland. 3. Route the cables for power in and Modbus communicaon through the le cable gland. 4. To connect this device to the next device in a daisy chain network:
a. Unscrew the strain relief on the right cable gland. b. Route the Modbus cable to the next device through the right cable gland.

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5. Connect the wires according to the table below.

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Tout/B Vout/A
24V GND

Tout/B Vout/A 24V GND

Modbus RTU (RS-485)
24 Vac/dc supply 0 V

The nominal wire terminal screw ghtening torque is 0.4 Nm. Important: Do not use excessive force when you ghten the wiring terminal screws.

6. Tighten the strain reliefs.
4.4 Warm-up mode

This device starts up in warm-up mode. The warm-up mode connues for 15 seconds aer startup. During the warmup me, the output signals are at the defined minimum values and the relay does not operate. If the device has a display, text Warming up is shown on the display. The device starts to operate correctly aer the warm-up me.
4.5 Configuring settings via device menu

See the figure below for the full menu structure for all models with display (-D) excluding the Modbus models (-MOD). For Modbus model menu structure, see secon Available sengs for Modbus on page 19.

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NO
V RANGE MAX
*10 m/s, 1…20 m/s *2000 ft/min,
200…4000 ft/min

VEL. UNIT
*m/s, ft/min
TEMP. UNIT
*°C, °F
PID IN USE
*no, yes

YES
REFERENCE SP
*5.00 m/s, 0.01…20.00 m/s *1000 ft/min, 2…4000 ft/min
P-VALUE
*1.00, 0.00…99.99
I-VALUE
*1.00, 0.00…99.99
D-VALUE
*1.00, 0.00…99.99

V OUT SCALE
0-5 V, *0-10 V, 2-10 V, Custom

Custom
V OUT MIN
*0 V, 0…10 V

T RANGE MIN
*0 °C, -25…40 °C, *32 °F, -13…104 °F

V OUT MAX
*10 V, 0…10 V

T RANGE MAX
*50 °C, 0…50 °C, *122 °F, 32…122 °F

T OUT SCALE
0-5 V, *0-10 V, 2-10 V, Custom

Custom

T OUT MIN
*0 V, 0…10 V

AVT-D-R

RELAY DIR
*Rise, Fall
RELAY SP
*5.00 m/s, 0.01…20.00 m/s, 1000 ft/min, 2…4000 ft/min
RELAY HYST
*0.5 m/s, 0.1…20.00 m/s *100 ft/min, 20…4000 ft/min

T OUT MAX
*10 V, 0…10 V

EXIT MENU

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Tout/B

Vout/A

24V

GND

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A. SELECT buon B. UP buon C. DOWN buon
1. Open the cover.
WARNING: Do not open the device cover when the relay mains supply voltage is connected. Always do the commissioning of the device in de-energised relay electricity network.
CAUTION: When the power supply is connected, be extra careful when handling the product without the cover. 2. Press the SELECT buon for two seconds to acvate the device menu. 3. Use the UP and DOWN buons to navigate the menu. 4. Press the SELECT buon to change the value of a menu item. 5. Press the UP or DOWN buon to select a value. 6. Press the SELECT buon to accept the new value and to return to menu navigaon. 7. Navigate to the EXIT MENU view and press the SELECT buon to save the sengs and exit the menu.
4.5.1 Available settings for velocity and temperature
For Modbus model sengs, see chapter Available sengs for Modbus on page 19.
4.5.1.1 The Vel. unit menu
You can select the velocity unit for the device display and the velocity output in the VEL. UNIT menu. The available velocity units are m/s and ft/min. The default value is m/s.
4.5.1.2 The Temp. unit menu
You can select the temperature unit for the device display and the temperature output in the TEMP. UNIT menu. The available temperature units are °C and °F. The default value is °C.

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4.5.1.3 The PID in use menu

PID IN USE

YES

V RANGE MAX
10 m/s

REFERENCE SP
5 m/s

P-VALUE
1.00

I-VALUE
1.00

D-VALUE
1.00
You can select if the PID control funcon is in use in the PID IN USE menu. The available values are no and yes. The default value is no. If you select no, the next menu item is V RANGE MAX. If you select yes, the next menu items are REFERENCE SP, P-VALUE, I-VALUE and D-VALUE.
The V range max menu
You can select the maximum value for air velocity measurement range in the V RANGE MAX menu. You can select the maximum velocity measurement range between 1 m/s and 20 m/s. The default value is 10 m/s. If you selected ft/min in the VEL. UNIT menu, you can select the maximum velocity measurement range between 200 /min and 4000 /min. You can adjust the value by 200 /min steps. The default value is 2000 ft/min.
The Reference SP menu
You can select the setpoint for the PID controller in the REFERENCE SP menu. You can adjust the value by 0.1 m/s or 1 /min steps depending on the selected air velocity unit. The default value is 5 m/s or 1000 /min.
The P-value, I-value and D-value menus
You can select the proporonal gain in the P-value menu. You can adjust the value by 0.01 unit steps. The default value is 1.00. You can select the integral gain in the I-value menu. You can adjust the value by 0.01 unit steps. The default value is 1.00. You can select the derivave gain in the D-value menu. You can adjust the value by 0.01 unit steps. The default value is 1.00. You can select the P-value, I-value and D-value between 0 and 99.99.
4.5.1.4 The V out scale menu
You can select the air velocity output scale in the V OUT SCALE menu. The available values are 0-5 V, 0-10 V, 2-10 V and custom. The default value is 0-10 V. If you select custom, you can set the minimum and maximum values for the air velocity output scale.
The V out min menu
If you selected custom in the V OUT SCALE menu, you can select the minimum value for the air velocity output scale in the V OUT MIN menu. You can select a value between 0 V and 10 V. You can adjust the value by 1 V steps. The default value is 0 V.

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Note: You can select a minimum value that is bigger than the maximum value to reverse the operang direcon.
The V out max menu
If you selected custom in the V OUT SCALE menu, you can select the maximum value for the air velocity output scale in the V OUT MAX menu. You can select a value between 0 V and 10 V. You can adjust the value by 1 V steps. The default value is 10 V.
Note: You can select a maximum value that is smaller than the minimum value to reverse the operang direcon.
4.5.1.5 The T range min menu
You can select the minimum value for temperature measurement range in the T RANGE MIN menu. You can select a value between -25 °C and 40 °C. You can adjust the value by 5 °C steps. The default value is 0 °C. If you selected °F in the TEMP. UNIT menu, you can select a value between -13 °F and 104 °F. You can adjust the value by 2 °F steps. The default value is 32 °F.
4.5.1.6 The T range max menu
You can select the maximum value for temperature measurement range in the T RANGE MAX menu. You can select a value between -15 °C and 50 °C. You can adjust the value by 5 °C steps. The default value is 50 °C. If you selected °F in the TEMP. UNIT menu, you can select a value between 5 °F and 122 °F. You can adjust the value by 2 °F steps. The default value is 122 °F.
4.5.1.7 The T out scale menu
You can select the temperature output scale in the T OUT SCALE menu. The available values are 0-5 V, 0-10 V, 2-10 V and custom. The default value is 0-10 V. If you select custom, you can set the minimum and maximum values for the temperature output scale.
The T out min menu
If you selected custom in the T OUT SCALE menu, you can select the minimum value for the temperature output scale in the T OUT MIN menu. You can select a value between 0 V and 10 V. You can adjust the value by 1 V steps. The default value is 0 V.
Note: You can select a minimum value that is bigger than the maximum value to reverse the operang direcon.
The T out max menu
If you selected custom in the T OUT SCALE menu, you can select the maximum value for the temperature output scale in the T OUT MAX menu. You can select a value between 0 V and 10 V. You can adjust the value by 1 V steps. The default value is 10 V.
Note: You can select a maximum value that is smaller than the minimum value to reverse the operang direcon.

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4.5.2 Relay settings
RELAY DIR
Rise
RELAY SP
5 m/s
RELAY HYST
0.5 m/s

4.5.2.1 The Relay dir menu
This menu is shown only if the transmier has a relay output (-R models). Relay operang direcon defines if the relay switches on or off when the air velocity is more than the setpoint value. You can select the relay operang direcon in the RELAY DIR menu. The available values are Rise and Fall. The relay switches on if Rise is selected and the air velocity is more than the setpoint value. If Fall is selected, the relay switches on when the air velocity is less than the setpoint value. The default value is Rise.
4.5.2.2 The Relay SP menu
This menu is shown only if the transmier has a relay output (-R models). You can set the velocity setpoint for the relay in the RELAY SP menu. You can set this value with an accuracy of two decimals. The default value is 5 m/s or 1000 ft/min.
4.5.2.3 The Relay hyst menu
This menu is shown only if the transmier has a relay output (-R models). This seng defines how much the air velocity must drop below the setpoint before the relay switches off if Rise is selected in the RELAY DIR menu. The funcon is opposite if Fall is selected in the RELAY DIR menu. You can set the hysteresis value for the relay in the RELAY HYST menu. You can select a value between 0.1 and 20.0 m/s. You can adjust the value by 0.1 m/s steps. The default value is 0.5 m/s. If you selected ft/min in the VEL. UNIT menu, you can select a value between 20 /min and 4000 /min. You can adjust the value by 20 /min steps. The default value is 100 ft/min.
4.5.3 The Exit menu view
Navigate to the EXIT MENU view and press the SELECT buon to save the sengs and exit the menu.
4.5.4 Available settings for Modbus
The figure below shows the menu structure for the Modbus models with display (-MOD-D). These menu sengs are only available in the Modbus models.

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BAUD RATE
19200
ADDRESS
1
PARITY BIT
None
VEL. UNIT
m/s
TEMP. UNIT
°C
EXIT MENU
4.5.4.1 The Baud rate menu
You can select the bus speed in the BAUD RATE menu. The bus speed can be 9600, 19200 or 38400 bits/s. The default baud rate is 19200 bits/s.
4.5.4.2 The Address menu
You can select the Modbus address in the ADDRESS menu. Address range is 1…247. The default value is 1.
4.5.4.3 The Parity bit menu
You can select Modbus parity in the PARITY BIT menu. The available values for bus parity are none, odd and even. The default seng is none.
4.5.4.4 The Vel. unit menu
You can select the velocity unit for the device display and the velocity output in the VEL. UNIT menu. The available velocity units are m/s and ft/min. The default value is m/s.
4.5.4.5 The Temp. unit menu
You can select the temperature unit for the device display and the temperature output in the TEMP. UNIT menu. The available temperature units are °C and °F. The default value is °C.
4.5.4.6 The Exit menu view
Navigate to the EXIT MENU view and press the SELECT buon to save the sengs and exit the menu.
4.6 Locking the cover
WARNING: There is a hazardous voltage inside the R-model devices. Always lock the cover before the relay mains supply voltage is connected. 1. Close the cover.

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2. Tighten the cover locking screw (-R models).
A A. Cover locking screw 3. Make sure that the cover does not open without tools.

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Maintenance

5.1 Cleaning the probe and the sensor element
Dust, grease and other dirt can accumulate on the sensor element over me and decrease the measurement accuracy of the sensors. Clean the probe and the sensor element regularly. The required cleaning interval depends on the air cleanliness. Do not clean the sensor element with detergents or other chemicals. 1. Disconnect the device supply voltage. For the -R models, disconnect the device supply voltage and the relay mains
supply voltage. 2. Clean the probe with a so cloth.
A

B
A. Probe B. Sensor element 3. Clean the sensor element with compressed air. Apply compressed air lightly to the sensor element to prevent damage.
Important: Do not use too high pressure, touch the sensor element or use other cleaning methods that cause mechanical stress. Mechanical stress damages the sensor element and changes the measurement accuracy of the sensors.

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6 Modbus

6.1 Modbus properties
The Modbus communicaon is only available in -MOD models. The parameter memory durability allows at least 1 000 wring cycles.
Note: The changes to the Modbus communicaon sengs take effect aer you restart the device.

Protocol Bus speed Data bits Parity Stop bits Modbus ID Unit load

RS-485 Modbus RTU 9600/19200*/38400 bit/s 8 none*/odd/even 1 1* 1/8 UL * factory seng

6.2 Modbus function codes

The device supports the following Modbus funcon codes.

Decimal 3 4 6 16

Hexadecimal 0x03 0x04 0x06 0x10

Function Read Holding Registers Read Input Registers Write Single Register Write Mulple Registers

6.3 Modbus registers

6.3.1 Input registers

General
Register 0 1 2 3 4…99

Parameter description Velocity m/s Velocity /min Temperature °C Temperature °F Reserved for future use

Data type U16 U16 S16 S16

Values 0…2000 0…4000 -250…500 -130…1220

Device model details

Parameter description Register count Format version Display

Data type U16 U16 U16

Values 0…99 0…65535 0…1

Range 0…20 m/s 0…4000 /min -25.0…50.0 °C -13.0…122.0 °F
Range 0…99 0…65535 0. no 1. yes

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Parameter description Buons
Number of relays Analogue outputs
Modbus
Connector for
PID controller

Data type U16

Values 0…1

U16

0…1

U16

0…1

U16

0…1

U16

0…1

U16

0…1

Device information

Parameter description Device type Hardware version Producon number, most significant word Producon number, least significant word Configuraon number, most significant word Configuraon number, least significant word Reserved for MyTool® Ethernet MAC address 1 Ethernet MAC address 2 Ethernet MAC address 3 Wireless MAC address 1 Wireless MAC address 2 Wireless MAC address 3 Memory state

Data type U16 U16 U16
U16
U16
U16
U16 U16 U16 U16 U16 U16 U16 U16

Values 0…65535 0…65535 0…65535
0…65535
0…65535
0…65535
0 0 0 0 0 0 0…9

9916 9917

Configuraon compability number

U16

Firmware ID, most significant word

U16

0…65535 0…65535

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Range 0. no 1. yes
0….1
0. no 1. yes
0. no 1. yes
0. no 1. yes
0. no 1. yes

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Range 0…65535 0…65535 0…65535
0…65535
0…65535
0…65535
0 0 0 0 0 0 0. Idle 1. Loading latest
configuraon 2. Saving latest configuraon 3. Loading default
configuraon 4. Saving default
configuraon 5. Loading calibraon 6. Saving calibraon 7. Saving applicaon state 8. Chip erase in progress 9. Cloud configuraon
management 0…65535 0…65535
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Parameter description Firmware ID, least significant word Firmware version (major, minor) Firmware version (revision, build) Reserved for MyTool® MyTool® compability number

Data type U16 U16 U16 U16 U16

Values 0…65535 0…65535 0…65535 25 0

6.3.2 Holding registers

Range 0…65535
0…65535
0…65535
25
0. Compability number not assigned (feature is not in use)

Modbus
Register 0

Parameter description Bus speed

Address

Parity bit

3 4 5…199

Velocity unit Temperature unit Reserved for future use

Data type U16

Values 0…2

U16

1…247

U16

0…2

U16

0…1

U16

0…1

Range 0. 9600 1. 19200 2. 38400
1…247
0. none 1. even 2. odd
0. m/s 1. /min
0. Celsius 1. Fahrenheit

Default 1
1 0
0 0

MyTool
Register 200
201 202 203 204 205 206 207 208

Parameter description PID in use

Data type U16

Values 0…1

Velocity range max. (m/s)

U16

Velocity range max. (/min)

U16

Velocity control setpoint (m/s)

U16

Velocity control setpoint (/min) U16

Velocity control P factor

U16

Velocity control I factor

U16

Velocity control D factor

U16

Velocity / velocity control signal U16 scale

1…20 2…40 1…2000 2…4000 0…9999 0…9999 0…9999 0…3

209

Velocity / velocity control signal U16

0…10

scale custom min.

210

Velocity / velocity control signal U16

0…10

scale custom max.

211

Temperature range min. (°C)

U16

-25…40

Range 0. no 1. yes 1…20 m/s 200…4000 /min 0.01…20 m/s 2…4000 /min 0…99.99 0…99.99 0…99.99 0. 0…5 V 1. 0…10 V 2. 2…10 V 3. Custom 0…10 V
0…10 V
-25…40 °C

Default 0
10 20 500 1000 100 100 100 1
0
10
0

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Parameter description Temperature range min. (°F) Temperature range max. (°C) Temperature range max (°F) Temperature output signal scale

Data type U16 U16 U16 U16

Values -13…104 -15…50 5…122 0…3

216

Temperature output signal scale U16

0…10

custom min.

217

Temperature output signal scale U16

0…10

custom max.

218

Relay operang direcon

U16

0…1

219

Relay setpoint (m/s)

U16

1…2000

220

Relay setpoint (/min)

U16

2…4000

221

Relay hysteresis (m/s)

U16

1…2000

222

Relay hysteresis (/min)

U16

2…4000

Range -13…104 °F -15…50 °C 5…122 °F 0. 0…5 V 1. 0…10 V 2. 2…10 V 3. Custom 0…10 V
0…10 V
0. Rise 1. Fall 0.01…20 m/s 2…4000 /min 0.01…20 m/s 2…4000 /min

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Default 32 50 122 1
0 10 0
500 1000 50 100

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7 Disposal
This device is considered as electrical and electronic equipment for disposal in terms of the applicable European Direcve. At the end of life, the product must enter the recycling system at an appropriate collecon point.
· The device must be disposed through channels provided for this purpose. · The disposal must be completed according to the local and currently applicable laws and regulaons.
Generally all metals can be recycled as material. Plascs and cardboard packaging material can be used in energy recovery. Printed circuit boards need selecve treatment according to IEC 62635 guidelines. To aid recycling, plasc parts are marked with an appropriate idenficaon code. Contact your local HK Instruments distributor for further informaon on environmental aspects and recycling instrucons for professional recyclers.

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Warranty policy

The seller is obligated to provide a warranty of five years for the delivered goods regarding material and manufacturing. The warranty period is considered to start on the delivery date of the product. If a defect in raw materials or a producon flaw is found, the seller is obligated, when the product is sent to the seller without delay or before expiraon of the warranty, to amend the mistake at his/her discreon either by repairing the defecve product or by delivering free of charge to the buyer a new flawless product and sending it to the buyer. Delivery costs for the repair under warranty will be paid by the buyer and the return costs by the seller. The warranty does not comprise damages caused by accident, lightning, flood or other natural phenomenon, normal wear and tear, improper or careless handling, abnormal use, overloading, improper storage, incorrect care or reconstrucon, or changes and installaon work not done by the seller. The selecon of materials for devices prone to corrosion is the buyer’s responsibility, unless otherwise is legally agreed upon. Should the manufacturer alter the structure of the device, the seller is not obligated to make comparable changes to devices already purchased. Appealing for warranty requires that the buyer has correctly fulfilled his/her dues arisen from the delivery and stated in the contract. The seller will give a new warranty for goods that have been replaced or repaired within the warranty, however only to the expiraon of the original product’s warranty me. The warranty includes the repair of a defecve part or device, or if needed, a new part or device, but not installaon or exchange costs. Under no circumstance is the seller liable for damages compensaon for indirect damage.

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Documents / Resources

HK INSTRUMENTS AVT Air Velocity Transmittera [pdf] User Guide
AVT Air Velocity Trans Mittera, Velocity Trans Mittera, Trans Mittera

References

User Manual

HK INSTRUMENTS AVT Air Velocity Transmittera

Specifications

Product Usage Instructions

FAQs

Introduction

Safety precautions

Description of the product

Commissioning

Maintenance

Warranty policy

Documents / Resources

References

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