About data subscriptions and remote control

The EK80 Wide band scientific echo sounder allows you subscribe to echo data and to control the operation from your own remote application. In this way you can create your own software for controlling the EK80 operations. Such operations may for example include start/stop pinging, changing ping interval, or start/stop data recording.

By means of your client application you can subscribe to data from the EK80. This means that you can ask the EK80 to continuously send various data (for example Depth data, Target Strength data or Integration data) to your client application.

Note

In this context the EK80 Processor Unit is regarded as the "server". The EK80 program is the "server application". The program you make yourself for running on a local computer is referred to as the "client application".

The communication between the EK80 program and your own client application is done by exchanging UDP messages via the local area network (LAN). Command and response messages are all text messages on XML format. Subscribed data updates are binary data structures. These must be decoded using the relevant information about the data structure.

UDP uses a simple connectionless transmission model with a minimum of protocol mechanism. It has no handshaking dialogues, and thus exposes the user's program to any unreliability of the underlying network protocol. There is no guarantee of delivery, ordering, or duplicate protection. UDP provides checksums for data integrity, and port numbers for addressing different functions at the source and destination of the datagram.

With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol (IP) network without prior communications to set up special transmission channels or data paths. UDP is suitable for purposes where error checking and correction is either not necessary or is performed in the application, avoiding the overhead of such processing at the network interface level.

https://en.wikipedia.org/wiki/User_Datagram_Protocol, April 2016

Local computer (normally connected to the local area network) running your own program ("client application").

Processor Unit running the EK80 program ("server application").

Subscriber parameter updates (UDP/Binary)

Subscribed data updates (UDP/Binary)

Commands and responses (UDP/XML)