KONGSBERG PI50 Fishing Troubleshooting Guide

KONGSBERG PI50 System Troubleshooting Guide

Simrad PI50 is a wireless fishing monitoring system designed specifically for commercial fisheries, widely used in bottom trawl, mid trawl, purse seine, and Danish style trawl operations. It receives various sensors installed on the net (depth, height, net mouth expansion, catch, bottom contact, temperature, geometric posture, etc.) through underwater acoustic communication, providing real-time net status and marine environment data for the crew. Quick and accurate troubleshooting is key to ensuring fishing efficiency when the system experiences signal loss, data jumps, or abnormal readings. This article is based on the official PI50 operation manual, extracting a complete guide from sensor configuration, receiver calibration to typical fault handling, to help on-site engineers and onboard operators systematically diagnose and solve common problems in the PI50 system.

System composition and communication principles

The PI50 system consists of the following core units:

Processor unit (computer): runs PI50 software, displays sensor data, and provides a user interface.

Sensor Receiver: Available in 6-channel (PI50) or 10 channel (PI60) models, responsible for receiving and decoding acoustic signals from underwater sensors.

Hydrophone: Installed at the bottom of the ship, it is divided into net type (beam horizontal 90 ° x vertical 30 °) and trawl type (50 ° x 30 °), and can also be used as an omnidirectional portable hydrophone.

Wireless sensors: including PI series and PX MultiSensor, can measure depth, height, net mouth expansion, catch, bottom contact, temperature, roll/pitch, net geometry, etc.

The sensor sends data to the hydrophone through acoustic pulses, and after demodulation by the receiver, it is transmitted to the computer through an RS-232 serial port (4800 baud, 8 data bits, no verification). Each sensor occupies one communication channel, while dual measurement sensors (such as expansion/depth) occupy two channels. The system supports a maximum of 6 or 10 measurement channels.

Understanding this communication link is the foundation of troubleshooting: any abnormality in any link (sensor battery, hydrophone installation, receiver power supply, serial cable, software configuration) may result in data loss.

Sensor configuration and common configuration errors

2.1 Sensor selection and parameter matching

In the Setup → Select Sensors dialog box, the operator needs to complete the following key configurations:

Select the sensor type (such as Depth 300m, Catch, Spread, etc.) from the Available Sensors list and click on it[ ▶] Add to the Selected Sensors list.

In the Selected Sensors list, adjust the upper and lower order of sensors to correspond to the screen display order.

The Sensor Configuration area needs to be set one by one:

Label ID: Sensor physical label number (must be unique).

Label Name: An alias used only for dialog box recognition.

Update Rate: It must be consistent with the update rate set internally by the sensor (Normal or Fast). The PX MultiSensor is fixed to Normal.

Sensor Value Name: The name displayed in the sensor view, such as "Left Mesh Panel" or "Right Mesh Panel".

Channel Number: The communication channel number (1-6 or 1-10) used by the sensor. When multiple sensors of the same type are used simultaneously, the channel numbers must be different.

Offset: The depth sensor is automatically filled in after calibration; Expanding the sensor requires manually inputting the offset of the connection point (± 99 m).

The most common configuration error:

Update Rate mismatch → No data or data refresh exception.

Duplicate Channel Number → Data Conflict, both sensors are invalid.

The depth sensor has selected the wrong range (such as selecting Depth 1000m when the sensor is a 600m version) → serious deviation in depth reading.

2.2 Special settings for dual measurement sensors

For dual channel sensors such as Spread/Depth and Height/Depth, two channels need to be occupied. When configuring:

Select "Spread/Depth" or "Twin Spread" in the Available Sensors instead of adding Spread and Depth separately.

The two Sensor Value Names of the dual measurement sensor can be named separately (such as "Left Mesh Depth" and "Left Mesh Expansion").

For Geometry measurement (requiring three sensors): one Geometry sensor (or PX MultiSensor) is placed in the center of the back mesh, and two remote sensors (or Mini-R responders) are placed on the mesh board. When measuring geometry, the PX MultiSensor on the mesh board must be installed "in reverse" (with the sensor tip pointing towards the back mesh).

Receiver settings and signal quality optimization

The receiver parameters directly affect the data stability and operating distance, which can be adjusted in the Setup → Receiver dialog box.

3.1 Detection Threshold

This parameter determines the sensitivity of the receiver to the signal. PI50 uses two ranges:

3-14: Increasing the value=raising the threshold, set to around 8 for extremely long distances (>1500 m) and low interference hours.

15-20: The main range for normal use, increasing the value=decreasing the threshold. The default value is 17.