AIT Lablink Redis Client

Lablink client for interfacing to a Redis database. Its main purpose is to interface to AIT’s roadb (Redis-Opal Asynchronous Data Buffer) in order to access measurement data from a real-time simulation running on an OPAL-RT system. Similarly, the client allows sending commands and set points to a running simulation. The client can also be used in a basic mode, to map a Lablink datapoint to a Redis key.

See the examples section for more infos.

Note

in order to work with OPAL-RT, the roadb service should be running on the OPAL target computer.

Installation

Find information about the installation of the Lablink Redis client here.

Maven project dependency

The Lablink Redis client’s compiled Java package is available on the Maven Central Repository. Use it in your local Maven setup by including the following dependency into your pom.xml:

<dependency>
  <groupId>at.ac.ait.lablink.clients</groupId>
  <artifactId>redisclient</artifactId>
  <version>0.0.2</version>
</dependency>

Note

You may have to adapt this snippet to use the latest version, please check the Maven Central Repository.

Installation from source

Installation from source requires a local Java Development Kit installation, for instance the Oracle Java SE Development Kit 13 or the OpenJDK.

Check out the project and compile it with Maven:

git clone https://github.com/ait-lablink/lablink-redis-client
cd lablink-redis-client
mvnw clean package

This will create JAR file redisclient-<VERSION>-jar-with-dependencies.jar in subdirectory target/assembly.

Running the clients

Find basic instructions for running the client here.

Invoking the clients from the command line

When running the clients, the use of the -c command line flag followed by a local configuration file or the URI to the configuration is mandatory (see here for more on configuring the Lablink Redis client).

For example, on Windows this could look something like this:

SET LLCONFIG=http://localhost:10101/get?id=
SET CONFIG_FILE_URI=%LLCONFIG%ait.test.redis.config

SET REDIS_OPAL=at.ac.ait.lablink.clients.redisclient.RedisOpalClient
SET REDIS_JAR_FILE=\path\to\lablink-redis-client\target\assembly\redisclient-<VERSION>-jar-with-dependencies.jar

java.exe -cp "%REDIS_JAR_FILE%" %REDIS_OPAL% -c %CONFIG_FILE_URI%

Configuration

Find the reference for writing a configuration for a Lablink Redis client here.

Overview

The configuration has to be JSON-formatted.

Basic Lablink Client Configuration

Required parameters:

clientName: client name
groupName: group name
scenarioName: scenario name
labLinkPropertiesUrl: URI to Lablink configuration
syncHostPropertiesUrl: URI to sync host configuration

Redis Database Connection Configuration

Required parameters:

redisIP: IP address of Redis database
redisPort: connection port of Redis database

Optional parameters:

msTimeInterval: time interval in milliseconds for retrieving data values (measurements) from the Redis database (default: 5000)

Commands / Measurements Configuration

For interacting with the Redis database, the client defines measurements (i.e., data values to be read from the database) and commands (i.e., data values to be written to the database). Both can be either defined in a local configuration file (with Redis keys in separate lines) or as JSON arrays.

Configuration via local file:

cmdsFile: path to local configuration file defining commands via Redis keys in separate lines
measFile: path to local configuration file defining measurements via Redis keys in separate lines

Configuration via JSON array:

commands: JSON array defining commands via Redis keys in separate entries
measurements: JSON array defining measurements via Redis keys in separate entries

Note

Redis keys may not contain slashes (/)!

Example Configuration

The following is an example configuration using local configuration files to define commands / measurements:

{
  "clientName" : "RedisOpalClient",
  "groupName" : "RedisOpalDemo",
  "scenarioName" : "RedisOpalScenario",
  "syncHostPropertiesUrl" : "http://localhost:10101/get?id=ait.example.all.sync-host.properties",
  "labLinkPropertiesUrl" : "http://localhost:10101/get?id=ait.example.all.llproperties",
  "redisIP" : "192.168.100.200",
  "redisPort" : "6379",
  "cmdsFile" : "commands.sgnl",
  "measFile" : "measurements.sgnl"
}

The following is an example configuration using JSON arrays to define commands / measurements:

{
  "clientName" : "RedisOpalClient",
  "groupName" : "RedisOpalDemo",
  "scenarioName" : "RedisOpalScenario",
  "syncHostPropertiesUrl" : "http://localhost:10101/get?id=ait.example.all.sync-host.properties",
  "labLinkPropertiesUrl" : "http://localhost:10101/get?id=ait.example.all.llproperties",
  "redisIP" : "192.168.100.200",
  "redisPort" : "6379",
  "commands": [
    "cmd_Test.line_1_Line.Data.Points.P1",
    "cmd_Test.line_1_Line.Data.Points.Q1"
  ],
  "measurements": [
    "meas_Test.ext_el_grid_Generator.Data.Points.Vmag",
    "meas_Test.ext_el_grid_Generator.Data.Points.Vang"
  ]
}