About Spread Sensors

You can use Spread sensors in three different modes: single trawl, twin trawls with double distance and twin trawls with triple distance. The following schemas illustrate the three modes and how Spread sensors communicate with each others.

Single Trawl

User case 1: Single trawl with single distance

Port Stbd Asks for answer
Answers
Sends data to the receiver (door spread distance, bearing, pitch and roll, depth...)
  • The port sensor (1) interrogates the starboard sensor (2) to know the distance between them (A). Then, it sends the distance to the receiver.
  • The sensors send data such as bearing, temperature, depth, pitch and roll to the receiver.

Twin Trawls

User case 2: Twin trawls with double distance

PortStbd Asks for answer
Answers
Sends data to the receiver (door spread distance, bearing, pitch and roll, depth...)
  • The port sensor (1) interrogates the clump (2) and starboard sensors (3) to know the distance with each one. Then, it sends the two distances (A, B) to the receiver.
  • All sensors send data such as bearing, temperature, depth, pitch and roll to the receiver.

User case 3: Twin trawls with triple distance

Port Stbd Asks for answer
Answers
Sends data to the receiver (door spread distance, bearing, pitch and roll, depth...)
  • The port sensor (1) interrogates the clump (2) and starboard sensors (3) to know the distance with each one. Then, it sends the two distances (A, B) to the receiver.
  • The clump sensor (2) interrogates the starboard sensor (3) to know the distance between them. Then, it sends the distance (C) to the receiver.
  • All sensors send data such as bearing, temperature, depth, pitch and roll to the receiver.

Dual Trawls

User case 4: Dual trawls with two sets of spread sensors

If you use two separate trawls, you need to install two sets of spread sensors. You can install them in two different ways: in the same way as for a single trawl on each trawl, or if you want to have the spread distance between the two inner doors, you can set up the following installation:
PortStbd Asks for answer
Answers
Sends data to the receiver (door spread distance, bearing, pitch and roll, depth...)

Sensors with triple distance are installed on the port trawl and sensors with single distance are installed on the starboard trawl.

  • The port sensor (master) (1) interrogates the starboard sensor (clump) on the port trawl (2) and the starboard sensor (slave) on the starboard trawl (3) to know the distance with each one. Then, it sends the distances (A and B) to the receiver.
  • The starboard sensor (clump) on the port trawl (2) interrogates the port sensor (slave) on the starboard trawl (3) to know the distance between them. Then, the distance (C) to the receiver.
  • The port sensor (master) on the starboard trawl (4) interrogates the starboard sensor (slave) on the starboard trawl (5) to know the distance between them. Then, it sends the distance (D) to the receiver.
  • All sensors send data such as bearing, temperature, depth, pitch and roll to the receiver.
Note: Make sure to put different ranging frequencies between the two sets of Spread sensors.

Summary of parameters

The table of geometry parameter defines the possible user cases for the Spread Sensors: