Configuration Guide

Common changes to Documents\Motion Applied\vTAG Service\AppConfig.json, organised by what you want to do. Restart vTAG Service after every change. For every setting, see the Configuration Reference.

Add or update — don't replace the whole file

The snippets on this page show only the settings involved. Change those values in your existing file and leave everything else as it is.

Connect to a broker on another machine

When: your Kafka broker isn't on the same PC as vTAG Service, for example a broker running in Docker on a separate server.

Set BrokerUrl to the broker's address. StreamCreationStrategy and Domain must match the producer that publishes your input data (for example, the StreamApiConfig in your Bridge Service configuration), or vTAG Service won't find its sessions.

Partition-based producers

If the producer uses the partition-based strategy (StreamCreationStrategy 1), also copy its PartitionMappings into vTAG Service's StreamApiConfig. Every stream needs a mapping, or it won't route correctly; see Partition Mappings.

{
  "StreamApiConfig": {
    "StreamCreationStrategy": 2,
    "BrokerUrl": "192.168.1.50:9094",
    "Domain": ""
  }
}

Result: at startup the console shows Support Library started (broker: "192.168.1.50:9094").

Read input data from a different data source

When: your telemetry is published to a data source other than Default.

Set VTagHost.DataSource to the data source name your producer uses.

{
  "VTagHost": {
    "DataSource": "Track"
  }
}

Result: vTAG Service runs the model on sessions published to Track.

Give the output session a fixed identifier

When: a downstream tool needs to find the output session by a known identifier. In most setups, leave the identifier to be generated automatically.

{
  "VTagHost": {
    "AutoGenerateSessionIdentifier": false,
    "SessionIdentifier": "Run42_vTAG"
  }
}

Result: the output session is created with the identifier Run42_vTAG instead of a generated one.

To change the session type the output session is published with, set VTagHost.SessionType (the default is vTAG).

Change how samples are batched

When: you want to tune how many time steps the model processes at once.

By default, vTAG Service processes samples in batches of 100 time steps. To use a different batch size, change BatchSize; to process one time step at a time, set BatchSamples to false.

{
  "VTagHost": {
    "BatchSamples": true,
    "BatchSize": 50
  }
}

Result: the console line Subscribing vTAG model to Support Library (frequency: ... Hz, batchSize: 50) shows the new batch size.

Point vTAG Service at your model's configuration files

When: the .pgv, .cfg or .pul files for your model aren't in C:\McLaren Applied.

Each setting is a list, so you can add more than one folder. In JSON, write each backslash twice.

{
  "EssentialsConfig": {
    "PgvPaths": [
      "C:\\McLaren Applied",
      "D:\\vTAG\\MyFirstVtagApp"
    ],
    "CfgPaths": [
      "D:\\vTAG\\Config"
    ],
    "PulFilePaths": [
      "C:\\McLaren Applied"
    ]
  }
}

Program vTAG Service from another PC

When: System Monitor runs on a different PC from vTAG Service.

By default the virtual vTAG unit uses 127.0.0.1, which only System Monitor on the same PC can reach. Set BindIpAddress to the IP address of the vTAG Service PC on the network that System Monitor uses, then connect System Monitor to that address.

{
  "VTagClient": {
    "BindIpAddress": "192.168.1.20"
  }
}

Run a different model

When: you want vTAG Service to run a different vTAG application.

You don't need to restart vTAG Service or edit AppConfig.json to change models. Reprogram the unit with System Monitor. vTAG Service pauses while programming is in progress, then reads the new model's parameters and subscribes to its inputs.

Console output

vTAG unit is being reprogrammed by System Monitor — pausing until it completes
vTAG reached Running — resetting state and rediscovering parameters

Make sure the new model's .pgv, .cfg and .pul files are in the folders listed in EssentialsConfig.

Override a setting without editing the file

When: you want to change a setting for one run, or from a script.

Environment variables override AppConfig.json. Use the section and property name separated by two underscores:

PowerShell

$env:StreamApiConfig__BrokerUrl = "192.168.1.50:9094"
& "C:\Program Files (x86)\Motion Applied\MA.DataPlatforms.vTAGService\MA.DataPlatforms.vTAGService.exe"