Bonner Q45U Ultrasonic Sensor in Practical Use

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.