3. eCAL Samples

The eCAL installation comes with a set of ready-to-use sample applications. So, let’s start one of those to see some eCAL communication!

Note

For now, you should start everything on the same PC. We will cover communication between multiple PCs in the next section.

3.1. Basic communication

Important

eCAL exchanges data over IP multicast. If you are using some third-party firewall, you may have to turn that off.

Disable McAffee Firewall

The sample we are going to use to try out the “normal” eCAL communication is ecal_sample_person_snd. Start it!

  • On Windows start C:\eCAL\samples\bin\ecal_sample_person_snd.exe

  • On Ubuntu call ecal_sample_person_snd from a terminal (it should be in your PATH)

You now have a console-based application that periodically prints some text to the terminal. In the background the application created a topic person and sends data to it. So, let’s add a subscriber that receives the data!

  • On Windows start :file:C:\eCAL\samples\bin\ecal_sample_person_rec.exe

  • On Ubuntu call ecal_sample_person_rec from a terminal

Congratulations! You are looking at your first local eCAL communication! The subscriber subscribed to the topic person and prints all data it receives to the terminal.

person communication

Tip

Start a second publisher and a second subscriber to see what happens! Both publishers will send their data to the same topic, so all subscribers will receive the data of all publishers.