KONGSBERG PI50 Fishing Troubleshooting Guide

Troubleshooting guidance:

When there is no sensor entering the water, random false data appears → the threshold is too low (the value is too large), and the value should be reduced (such as from 17 to 15) until the false data disappears.

Sometimes there is no data after the sensor is submerged → the threshold is too high (the value is too small), and the value should be increased (such as from 17 to 19).

Longest distance requirement (>1500 m): Try setting it to 8. If there is still interference, gradually increase until the interference disappears.

3.2 Filter Settings

Sensor Filter: Average multi frame data. Off (real-time), Weak (4 frames), Medium (8 frames), Strong (16 frames). When the operating distance is far but the data changes slowly, Wear can be used.

Catch/Bottom Filter: Suppresses fishing/bottom contact state jitter. Weak requires 2 stable transmissions before updating, while Strong requires 8 transmissions.

Multipath Filter: Suppresses reflections, spikes, and latency interference. Default On. Keep on in shallow water and multi reflection environments.

Phenomenon and Countermeasures:

The data jumps significantly but the trend is correct → Enable Multipath Filter.

Frequent flashing of catch indicator → Increase Catch/Bottom Filter intensity.

Large fluctuations in depth/expansion values without interference sources → Increase the Detection Threshold appropriately or enable the Weak Sensor Filter.

3.3 Identification of Interference Sources

Common interference comes from other acoustic equipment on board (echo sounder, sonar, Doppler log) or similar systems on nearby ships. Identification method:

Turn off the PI50 receiver and observe if the operating frequencies of other acoustic devices are similar (the PI50 operating frequency range is approximately 50-110 kHz).

Turn off other acoustic equipment on board one by one and determine the source of interference.

If it cannot be closed, you can try changing the Detection Threshold or using Multipath Filter.

Depth sensor calibration

The depth sensor must be immersed in saltwater for calibration to obtain accurate depth offset. Standard calibration process:

Attach a rope to the top suspension ring of the sensor and mark it 1 meter upwards from the bottom of the sensor.

Place the sensor in the water so that the mark is exactly level with the water surface (if you want to use the depth of the keel or transducer as a reference, adjust the mark accordingly).

In PI50, go to Setup → Calibration and click on Start Calibration.

The system automatically calculates the offset value and applies it. After completion, the sensor display should be 1.0 meter (or the selected reference depth).

Common reasons for calibration failure:

The sensor is not completely submerged or is not saltwater (with different densities of freshwater).

The water surface fluctuates greatly and the marking position is inaccurate → It is carried out in the still water area on the side of the ship.

The sensor battery is low → Replace the battery and recalibrate.

The depth reading is clearly incorrect but the calibration is normal: it is possible to select the wrong depth range (such as selecting 600m in the software when the actual sensor is 300m). Re select the correct version for Depth in Select Sensors.

Typical fault phenomena and troubleshooting

5.1 No sensor data, Pulse light does not flash

Receiver power supply: The receiver does not have a power switch, and if not in use for a long time, the power adapter needs to be disconnected. Check if the power adapter is functioning properly (24V DC output).

Serial communication: Confirm that the RS-232 cable connection between the computer and the receiver is correct (Rx → Tx, Tx → Rx, GND → GND), with a length not exceeding 50 meters. Check the COM port settings (4800,8, N, 1) in Setup → Installation → I/O Setup.

Hydrophone: Measure whether the hydrophone cable is broken; If there are two hydrophones (trawl/purse string), check if the selector is in the correct position.

Software license: If the license is invalid, communication is blocked. Check the Hardware ID and license status in Setup → Installation → Software License.

5.2 Some sensors have no data

Channel number conflict: Multiple sensors on the same channel → Use PI Configurator or PX Configurator software to change the channel number of one of the sensors and synchronously modify the Channel Number in Select Sensors.

Update rate mismatch: The sensor is set to Fast, select Normal in the software and change to the correct rate.

Sensor battery depleted: Test after charging. The PX sensor battery requires a dedicated charger.

Damage or water ingress: Check the shell and sealing ring.

5.3 Data jumps, spikes, or incorrect readings

Shallow water reflection: Enable Multipath Filter.

Strong interference: Gradually increase the Detection Threshold until the data is stable.

Bottom contact/fishing sensor false trigger: Increase Catch/Bottom Filter strength.

Error in offset value of extended sensor: Check if the Remote sensor is working properly on another mesh board and confirm the offset value (such as the distance from the installation point of the mesh board). You can temporarily set Offset to 0 for testing.