subscribe-to-scripted-signal

Scripted Signals

Remotive Broker enables you to perform computations on a stream of signals on the fly using your own Lua script while the signals are being streamed.

For a broader general overview, take a look at the Scripted Signals documentation.

Usage

One use case for Scripted Signals is mapping signals between different signal databases, for example, mapping your proprietary signal database to the Vehicle Signal Specification (VSS).

Prerequisites

Like all Python samples in this repository, the remotivelabs-broker pip package is required. Install all requirements using pip:

pip install -r requirements.txt

Examples

There are two example scripts in this sample.

The script subscribe_demo.py is designed to work with our Remotive Cloud Demo environment.

The script subscribe_standalone.py is a comprehensive standalone script that works with any Remotive Broker setup.

Demo example

You can try subscribe_demo.py when you don't have a broker at hand and just want to explore how scripted signals work.

Visit our Remotive Cloud Demo sample recording, select configuration_vss, then press Play. Wait for a new page to open, then select the Scripted Signals tab in the Examples to subscribe to signals from an external application panel to find the full command to run subscribe_demo.py.

The command will look something like this:

python3 subscribe_demo.py --url __BROKER_URL__ --x_api_key __API_KEY__ --script_path=scripts/Vehicle.Powertrain.TractionBattery.StateOfCharge.Displayed.lua

This command will subscribe to the signal named Vehicle.Powertrain.TractionBattery.StateOfCharge.Displayed, which is mapped from signals ID352BMS_energyStatus.BMS_nominalFullPackEnergy and ID352BMS_energyStatus.BMS_nominalEnergyRemaining, as defined in scripts/Vehicle.Powertrain.TractionBattery.StateOfCharge.Displayed.lua.

You can also change the frequency of emitted signals, as demonstrated in the following example:

python3 subscribe_demo.py --url __BROKER_URL__ --x_api_key __API_KEY__ --script_path=scripts/Vehicle.Powertrain.TractionBattery.StateOfCharge.Displayed_10Hz.lua

For an example of how to simply rename a signal, try the script below:

python3 subscribe_demo.py --url __BROKER_URL__ --x_api_key __API_KEY__ --script_path=scripts/Vehicle.Speed.lua

Standalone example

Using subscribe_standalone.py will reconfigure your broker with configuration from the configuration folder and upload sample recordings from the recordings folder.

The configuration folder contains the same configuration used in the demo example. Feel free to examine the files to see how to configure the scripted signals.

Let's imagine you are running a Remotive Broker at the URL http://192.168.4.1:50051.

Subscribe to the scripted signal Vehicle.Powertrain.TractionBattery.StateOfCharge.Displayed by running:

python3 subscribe_standalone.py --url http://192.168.4.1:50051 --script_path=scripts/Vehicle.Powertrain.TractionBattery.StateOfCharge.Displayed.lua

You can also change the frequency of emitted signals, as demonstrated in the following example:

python3 subscribe_standalone.py --url http://192.168.4.1:50051 --script_path=scripts/Vehicle.Powertrain.TractionBattery.StateOfCharge.Displayed_10Hz.lua

For an example of how to simply rename a signal, try the script below:

python3 subscribe_standalone.py --url http://192.168.4.1:50051 --script_path=scripts/Vehicle.Speed.lua