Bonner Q45U Ultrasonic Sensor in Practical Use

Bonner Q45U Ultrasonic Sensor in Practical Use

The unique advantages of ultrasonic ranging and Q45U positioning

In industrial automation, non-contact distance measurement is widely required in scenarios such as liquid level control, material positioning, collision prevention, and roll diameter detection. Optoelectronic sensors are greatly affected by the color, transparency, and surface reflection of objects; Although laser sensors have high accuracy, they are expensive and sensitive to harsh environments; Ultrasonic sensors utilize the principle of sound wave reflection and are not affected by the color and material of the target (as long as they are not strong sound-absorbing materials). They remain stable and reliable in complex environments such as dust, fog, and changes in light.

Banner Q45U series is a short range piezoelectric ultrasonic analog output sensor with a detection distance of 100mm to 1400mm (approximately 4~55 inches). It provides switchable analog output with 0~10V voltage or 4~20mA current, and can be programmed with buttons or remote signals to set the distance limit of the detection window. It also has built-in temperature compensation to ensure output accuracy throughout the entire working temperature range. Its sturdy design reaches IP67/NEMA 6P protection level and can withstand 1200 psi high-pressure water washing, making it very suitable for harsh environments such as food processing, outdoor equipment, and mobile machinery.

This article is based on the official data manual and provides a detailed analysis of the hardware configuration, parameter settings, window programming, response adjustments, and common on-site problem handling of Q45U from the perspective of an engineer.

Product Model and Selection Basis

2.1 Model Composition

The Q45U series offers three models, with the difference being the cable type:

Applicable scenarios for model connection method

Q45ULIU64ACR 2-meter (6.5-foot) integral cable fixed installation, no need for frequent disassembly

Q45ULIU64ACRQ 5-pin 7/8-inch -16UNF quick release connector commonly used in North American industry, with high waterproof rating

Q45ULIU64ARQ6 5-pin M12 quick release connector meets European and international standards and is widely used

All models come with built-in analog output (selectable voltage or current), PNP polarity (output is source current type), as well as TEACH button and remote programming input (yellow line).

2.2 Output Types

Q45U provides both voltage output (black line) and current output (white line) signal lines, but only one of them can be enabled through internal DIP switch 2. Factory default enable voltage output (0~10V). Users can choose based on the type of PLC analog input module: if the PLC accepts 0-10V, use black wire; If accepting 4-20mA (strong anti-interference ability, suitable for long-distance transmission), use a white line and turn DIP switch 2 to the ON position.

Attention: The current output is PNP type (i.e. source current output), and the load should be connected between the Output (white line) and the negative terminal of the power supply (blue line). The load impedance needs to be between 1-500 Ω to ensure 4-20mA linearity.

Installation and environmental requirements

3.1 Mechanical Installation

The Q45U shell is made of molded PBT polyester, with a transparent top cover made of acrylic material and sealed with an O-ring. The sensor body is cylindrical with a diameter of 30mm and can be installed through various brackets:

SMB30S: Spherical rotating bracket for adjusting angles.

SMB30C: 30mm split clamping bracket, securely fixed.

SMB30MM: 12 stainless steel bracket with adjustable curved groove.

During installation, it is important to ensure that the ultrasonic transducer surface (emitting surface) is facing the target and there are no obstacles ahead. The blind zone of the sensor is 100mm (minimum limit at the near end), which means it cannot detect objects smaller than 100mm. The maximum detection distance at the far end is 1400mm, but the target object size needs to be large enough: at a distance of 500mm, the minimum target is a 10mm x 10mm aluminum plate; At 1400mm, the minimum target requires a 35mm x 35mm aluminum plate. For non flat or irregular targets, it is recommended to conduct actual testing.

3.2 Environmental Tolerance

Working temperature: -25 ℃~+70 ℃, with built-in temperature compensation for the full temperature range.

Humidity: 100% relative humidity (condensable).

Protection level: IP67/NEMA 6P (can be immersed in a water depth of 1 meter for a short time), and can withstand 1200 psi flushing.

Vibration and shock: comply with Mil. Std. 202F, 10~60Hz 10G, shock 75G (working), 100G (non working).

3.3 Temperature compensation characteristics

Temperature changes can cause changes in the speed of sound in the air, thereby affecting the measurement distance. Q45U has a built-in temperature sensor for real-time compensation. Specific requirements:

The position accuracy of the window limit remains within ± 1% of the set distance within the range of 0 ℃~50 ℃.

Within the full temperature range (-25 ℃~+70 ℃), the accuracy is ± 2.5%.

Note: Temperature compensation can only calibrate the speed of sound and cannot eliminate the refraction of sound waves caused by temperature gradients or changes in the response of the transducer itself. Therefore, if the ambient temperature changes dramatically (such as from a cold storage to indoors), it is recommended to wait for the sensor to stabilize for at least 30 minutes before conducting critical measurements.

Hardware configuration: DIP switch detailed explanation

After opening the transparent top cover, use a small flathead screwdriver to pry open the two slots, remove the black inner cover, and you can see the 4-digit DIP switch. The DIP switch must be adjusted in the power-off state, otherwise it may damage the internal circuit or cause invalid settings.

4.1 DIP Switch 1: Output Slope

OFF (default): Inverse ratio mode. The farther the target distance, the lower the output value (voltage or current). Suitable for situations that require high output corresponding to close range.

ON: Proportional mode. The farther the target distance, the greater the output value. Suitable for liquid level monitoring: the higher the liquid level (the closer the distance), the smaller the output; The lower the liquid level (the farther the distance), the greater the output. Most users set it to proportional mode to conform to intuition.

4.2 DIP Switch 2: Output Type

OFF (default): Enable voltage output (black line, 0~10V).

ON: Enable current output (white line, 4-20mA). Note: Two output lines cannot be used simultaneously, only one can be selected. But the internal circuit of the sensor will still provide protection for unused outputs and will not be damaged.

4.3 DIP switch 3: Echo loss mode

When the sensor is unable to receive effective reflected echoes (such as the target being out of range, obstructed, absorbing materials, etc.), the output behavior is determined by this switch.

OFF (default, hold mode): Output the value held at the moment of echo loss. Suitable for scenarios where brief occlusion (such as moving objects passing quickly) does not require output jumps.

ON (minimum maximum mode): The output immediately jumps to the preset minimum value (0V or 4mA) or maximum value (10V or 20mA), and the specific end to which it jumps is determined by DIP switch 4.

4.4 DIP Switch 4: Minimum Maximum Default Values

This switch is only valid when DIP switch 3 is set to ON (minimum maximum mode).

ON (default): When echo is lost, the output jumps to the maximum value (10V or 20mA).

OFF: When echo is lost, the output jumps to the minimum value (0V or 4mA).

Typical application: In tank level detection, if the ultrasonic probe loses signal due to foam and steam, and the output is expected to jump to the maximum value (representing full tank) or minimum value (representing empty tank) to trigger the alarm, then set it accordingly.

Response speed adjustment

The response speed of Q45U is set through a single turn potentiometer (with a slot located below the inner cover). The potentiometer has 6 positions corresponding to different average output cycles. The faster the response speed, the greater the measurement noise; The slower the response speed, the smoother the output.

Location average number of cycles, response time (milliseconds), applicable scenarios

1 2 80 Rapidly changing targets, such as high-speed counting

2 4 160 General industrial movements

3 8 320 Routine testing

4 16 640 medium fluctuation

5 32 1280 gradual change process, such as liquid level

6 64 2560 extremely smooth output for stable control

Setting method: Use a flathead screwdriver to rotate the potentiometer so that the slot aligns with the scale line at the desired position (there is no number on the actual product, it needs to be estimated based on the rotation angle). The default factory position is usually 3 or 4.

Window limit programming (TEACH mode)

The core function of Q45U is to set two distance limits (near limit and far limit), and when the target is located between the two, the analog output changes linearly within a certain range; When the target exceeds the window, the output will saturate to the minimum or maximum value (depending on the output slope and window boundary). The minimum width of the window is 10mm.

6.1 Programming with buttons

There is a "Limits" button under the transparent top cover. The steps are as follows:

Enter programming mode: Long press the Limits button for about 2 seconds until the green LED goes out. At this time, the yellow LED is constantly on, and the red LED flashes according to the echo intensity.

Set the first limit: Place the target object in the desired position to become the near limit (or far limit), and then press the button briefly (<2 seconds). The green LED remains off, and the yellow LED flashes at 2Hz, indicating waiting for the second limit.

Set second limit: Move the target to another limit position and press the button briefly again. The sensor automatically returns to the operating mode (green LED is always on), and the window is set to complete.

Important rules:

The near and far limits can be programmed in any order.

If the target is placed in the same position and two limit positions are programmed, the sensor automatically generates a 10mm wide window centered at that position.

When programming the first limit, there is a 2-minute timeout, after which the programming mode will automatically exit, and the previous limit will remain unchanged. There is no timeout limit between the first and second limits.

Press and hold the button for more than 2 seconds at any time to cancel programming and restore the original window.

6.2 Remote Programming

The yellow wire (remote teaching input) can be used for external switch or PLC contact control programming. Apply a DC voltage of+5~24V to the yellow line (relative to the blue line 0V) for a duration that conforms to the timing diagram:

Enter programming: Apply high level for ≥ 2 seconds (similar to long pressing a button).

Set limit: Apply high level for less than 2 seconds (similar to short pressing a button).

Remote programming function and button programming are mutually exclusive: when using remote, buttons are disabled; When using buttons, remote input is ignored.

6.3 Visual feedback during programming process

The 5-segment LED "moving point" indicator displays the relative position of the target between 100mm and 1500mm.

The flashing in the first paragraph indicates that the target is below the near limit (too close to the sensor).

The flashing in the fifth paragraph indicates that the target is greater than 1400mm (beyond the recommended far limit range, but still within the detection range, with only a decrease in linearity).

If the target exceeds 1500mm, stable echoes may not be obtained.

Simulation output characteristics and load calculation

7.1 Voltage output (black line)

Range: 0~10V DC, maximum output current of 10mA (i.e. minimum load resistance of 1k Ω).

Resolution: 2mV (12 bit D/A conversion).

Low output impedance, can be directly connected to PLC analog input.

Calculation formula (assuming proportional slope, window near limit N, far limit F):

V_out=(Target Distance - N)/(F-N) × 10V

When the target is ≤ N, V_out = 0V； When the target is ≥ F, V_out = 10V。

7.2 Current output (white line)

Range: 4~20mA, load impedance 1~500 Ω.

Resolution: 3 μ A.

4-20mA is suitable for long-distance transmission (up to hundreds of meters) and is not easily affected by electromagnetic interference.

Calculation formula:

I-out=4mA+(target distance - N)/(F-N) × 16mA

Attention: The current output is PNP source current, which is provided by the sensor. The load must be connected between the output line (white line) and the power ground (blue line). The load impedance cannot exceed 500 Ω. If it exceeds 500 Ω, the output voltage will rise beyond the capacity of the internal constant current source of the sensor, resulting in output distortion or protection action. The minimum load impedance of 1 Ω (without considering wire resistance) is sufficient, but usually a 250 Ω resistor is used to convert it to 1-5V for PLC reading.

7.3 Output fault indication

The flashing green LED indicates a current output fault, usually caused by an open circuit of the white line (not connected to the load or disconnected line) leading to interruption of the current circuit. Voltage output faults (such as short circuit overload) will not flash the LED, but the output will enter a protective state.

On site debugging and troubleshooting

8.1 Sensor has no output or fixed output

Possible causes and solutions for the phenomenon

The green LED does not light up. If the power is not connected or reversed, check the brown (+) and blue (-) polarities; Measure the power supply voltage of 15-24V DC

The red LED is constantly off and no echo has been received. Check if there are any obstacles in front of the sensor; Whether the target distance exceeds the range; Is the target surface made of strong sound-absorbing materials (such as sponge or fabric)

The red LED flashes but the output remains unchanged. The window limit programming is incorrect. Re open the TEACH window to ensure that the near and far limit settings are reasonable

Output always in minimum/maximum echo loss mode (DIP3 ON) and no echo check DIP4 setting; Confirm that the target is within the window

8.2 Output nonlinearity or jumping

Response speed too fast: Reducing the response speed (increasing the average cycle) can smooth out the output.

Uneven or irregular target surface: Ultrasonic sensors measure the acoustic center of the target area, and irregular surfaces may cause point like reflections. At this point, the average cycle should be increased or a fixed reflector plate should be used.

Electrical noise: The sensor power supply is shared with high-power devices such as frequency converters, resulting in excessive power ripple. Isolation power supply or installation of filters should be used.

8.3 Large temperature drift

Confirm if the sensor is within the temperature compensation range. If the ambient temperature exceeds -25~70 ℃, linearity may be lost.

Long term direct sunlight or proximity to heat sources can cause local temperatures to be higher than ambient temperatures, affecting compensation accuracy. Sunshades should be installed or isolated from heat sources.

8.4 Misprogramming

If the programming mode is accidentally entered and no limit is set, the sensor will timeout and exit after 2 minutes, retaining the original window. But if the button is pressed incorrectly and the target position is incorrect, it may change the window. The solution is to reset TEACH to the correct window limit.

Application Cases and Selection Suggestions

9.1 Liquid level monitoring (water tank)

Requirement: Measure the water level at 0.3-1.2 meters and output 4-20mA to the PLC. The sensor is installed at the top of the water tank, with a distance of 1.2 meters when the tank is empty and 0.3 meters when it is full.

settings

Output type: Current (DIP2=ON).

Slope: Proportional (DIP1=ON), as the water level rises (distance decreases), the output should decrease, but usually PLCs expect high liquid levels to correspond to high currents. Adjustable logic or use inverse ratio.

In fact, if you want a high liquid level of 20mA, then a low liquid level (close range) corresponds to 20mA, so it should be set in inverse proportion (DIP1=OFF): the closer the distance (high liquid level), the greater the output.

Window: Near limit (full tank) 0.3m, far limit (empty tank) 1.2m. Place the target object separately during TEACH.

Echo loss: Set to minimum maximum value, default output maximum value (20mA) indicates fault (DIP3=ON, DIP4=ON).

Response speed: Position 4 or 5 (640ms or 1.28s), smooth liquid level fluctuations.

9.2 Detection of blockage at the discharge port

Requirement: Check if there is material accumulation at the funnel outlet (distance<500mm). Output within the range of 0~10V, output ≈ 10V when there is no material, output ≈ 0V when blocked (or vice versa).

settings

Voltage output (DIP2=OFF).

Proportional slope (DIP1=ON): The closer the distance (with material), the smaller the output.

Window: Near limit 100mm (closest to sensor), far limit 500mm (normal no-load distance). Set the far limit to the distance when there is no material and the near limit to the distance when there is blockage. Actual materials should be placed during TEACH.

Response speed: Position 2 (160ms), fast response.

Echo loss: Keep mode (DIP3=OFF) to avoid false alarms caused by brief loss of echo.

Maintenance and lifespan

Q45U is a solid-state sensor with no moving parts and a long theoretical lifespan. However, it should be noted that:

Regularly clean the transducer surface to avoid dirt and ice cover, otherwise the ultrasonic signal will be attenuated.

Check if the cable is damaged and if the quick disconnect joint is sealed (O-ring is not aging).

If in a reinforced corrosive environment (such as acid mist), PBT material may discolor, but its performance is not affected in the short term. It is recommended to use stainless steel brackets.

Alarm light indicator: Green flashing indicates an open circuit in the current circuit, and the wiring should be checked.