pips_pubsub

Runs on:

QNX Neutrino

Options:

-p

Enable pips_pubsub to run as a publisher. Running pips_pubsub as a publisher means that pips_pubsub publishes sensor data from the Sensor service to subscribers through PiPS with any of its supported providers (e.g. Fast RTPS).

-s

Enable pips_pubsub to run as a subscriber. Running pips_pubsub as a subscriber means that pips_pubsub subscribes to sensor data that's published through the Sensor service through PiPS. In turn, pips_pubsub publishes the data as interim data through the Sensor service.

-t

Specify the name of the provider that's to provide the publish-subscribe service through PiPS. Valid providers are:

• FASTRTPS — A C++ implementation of the Real Time Publish Subscribe (RTPS) protocol, which provides communications over UDP transport.
• RTICONNEXTDDS — A connectivity framework based on the Data Distribution Service (DDS) standard and designed for high-performance, scalable, realtime systems.
• RTIMICRODDS — A version of the RTI Connext framework designed for resource-constrained realtime systems.
• SOMEIP — The Scalable service-Oriented MiddlewarE over IP (SOME/IP) framework is designed for automotive systems and allows you to exchange large messages without fragmentation.

If you don't specify a provider name, then FASTRTPS is used.

Description:

The pips_pubsub application runs as either a publisher or subscriber, or both. The availability of the providers is determined by what you have installed on your target.

As a publisher, it reads data for each of your configured sensors in your sensor configuration file as different topics. It only publishes the data if there are subscribers subscribed to the data. As a subscriber, pips_pubsub subscribes to the data published from the publisher and in turn publishes the sensor data from the topics as interim data.

You must have the Sensor service already running before you can start pips_pubsub. The Sensor service must be started with the appropriate sensor and interim data configuration files for your publisher and subscriber. Your interim data configuration file must contain interim data units that directly correspond to sensor units in your sensor configuration file. You can refer to the example pair of sensor and interim data configuration files from your reference images:

• /etc/system/config/adas_example_capture.conf
• /etc/system/config/adas_example_capture_interim.conf

For more information on sensor and interim data configuration files, see “Sensor configuration file” and “Interim Data configuration file” respectively.

Examples:

• To start pips_pubsub as a publisher that's remote from the subscriber:

  You must start the Sensor service with the sensor configuration file first before you run pips_pubsub as a publisher. For example:

  # /bin/sensor -U 521:521 -r /roll -v -c /etc/system/config/adas_example_capture.conf &
  # pips_pubsub -p
              

• To start pips_pubsub as a subscriber that's remote from the publisher:

  You must start the Sensor service with the interim data configuration file first before you run pips_pubsub as a subscriber. For example:

  # /bin/sensor -U 521:521 -r /roll -v -d /etc/system/config/adas_example_capture_interim.conf &
  # pips_pubsub -s
              

• To start pips_pubsub where publisher and subscriber are local:

  You must start the Sensor service with the sensor and interim data configuration file first before you run pips_pubsub as a publisher and a subscriber. For example:

  # /bin/sensor -U 521:521 -r /roll -v -c /etc/system/config/adas_example_capture.conf -d /etc/system/config/adas_example_capture_interim.conf &
  # pips_pubsub -p -s
              

• To use pips_pubsub to demonstrate how to share sensor data between two targets (on publisher and one subscriber) via PiPS and SOME/IP:
  Note: To avoid confusion when you interpret output, you should start pips_pubsub and sensor_example from separate terminals.

  On the target whose sensor data you are publishing:

  1. Modify the SOME/IP publisher configuration file (/etc/system/config/vsomeip_publisher.cfg) to use the IP address of this target. For example:

     {
         "unicast" : "10.122.36.198",
         ...
                                 

     The SOME/IP publisher configuration file is a text-based file whose content is in JSON format.

  2. Slay the sensor service if it's already running on the target:

     # slay sensor
                                 

  3. Start the sensor service with the appropriate sensor configuration files for your target. For example:

     # /bin/sensor -U 521:521 -r /roll -v -c /etc/system/config/adas_example_capture.conf -d /etc/system/config/adas_example_capture_interim.conf &                           
                                 

  4. Run pips_pubsub as a publisher using SOME/IP:

     # pips_pubsub -p -t SOMEIP &
                                 

  On the target that's subscribing for sensor data:

  1. Modify the SOME/IP subscriber configuration file (/etc/system/config/vsomeip_subscriber.cfg) to use the IP address of this target. For example:

     {
         "unicast" : "10.122.36.193",
         ...
                                 

     The SOME/IP publisher configuration file is a text-based file whose content is in JSON format.

  2. Ensure that the Sensor service is running. If not, start the Sensor service:

     # /bin/sensor -U 521:521 -r /roll -v  -d /etc/system/config/adas_example_capture_interim.conf &
                                 

  3. Run pips_pubsub as a publisher using SOME/IP:

     # pips_pubsub -s -t SOMEIP &
                                 

  4. Run sensor_example to subscribe to streamed data from the sensors. For example if you are subscribing to data from sensor unit 1:

     # sensor_example -d -s
                                 

     Note: Ensure that you start sensor_example on this subscriber target before you start sensor_example on the other target.