NI gRPC Device Server and Client APIs

This repo contains the source code needed to build and run the NI gRPC Device Server for supported NI hardware driver APIs. Also contained in this repo are instructions and examples that demonstrate how to create client code that interacts with devices connected to an instance of the NI gRPC Device Server.

The server and the client APIs allow NI's instrumentation to be accessed and controlled through a remote interface via pre-defined APIs using a client/server architecture. The API is not a driver but instead a layer on top of the existing driver C APIs that provides remote capabilities.

For more detailed information on the server and API design refer to the wiki.

Supported NI drivers

NI Driver	Minimum Version Tested (Windows)	Minimum Version Tested (Linux)	Minimum Version Tested (Linux RT)
NI-DAQmx	21.0.0	21.0.0	21.0.0
NI-DCPower	20.6.0	20.1.0	20.7.0
NI-Digital Pattern Driver	20.6.0	Not Supported	Not Supported
NI-DMM	20.0.0	20.1.0	20.5.0
NI-FGEN	20.0.0	Not Supported	Not Supported
NI-RFmx Bluetooth	21.5.0	Not Supported	Not Supported
NI-RFmx LTE	21.5.0	Not Supported	Not Supported
NI-RFmx NR	21.5.0	Not Supported	Not Supported
NI-RFmx SpecAn	21.5.0	Not Supported	Not Supported
NI-RFmx WLAN	21.5.0	Not Supported	Not Supported
NI-RFSA	21.0.0	21.0.0	Not Supported
NI-RFSG	21.0.0	21.0.0	Not Supported
NI-SCOPE	20.7.0	20.1.0	20.7.0
NI-SWITCH	20.0.0	20.1.0	20.5.0
NI-XNET	21.5.0	21.5.0	21.5.0
NI-TClk	20.7.0	20.0.0	20.7.0

Build Status

Downloading a Release

Download the Server

1. (Windows Only) Download and install the latest Microsoft Visual C++ Redistributable for Visual Studio 2015, 2017 and 2019.
2. Navigate to the Releases page.
3. Download the latest Server Release .tar.gz or .zip for the desired platform.
4. Extract the contents of the .tar.gz or .zip to a directory with read and write permissions.
5. Run the server

• List of supported OS:
  • Windows 64-bit
  • Linux 64-bit
  • NI Linux RT

Download the Client Files

1. Navigate to the Releases page.
2. Download the latest Client Release's ni-grpc-device-client.tar.gz or ni-grpc-device-client.zip depending on the client platform.
3. Extract the contents of ni-grpc-device-client.tar.gz or ni-grpc-device-client.zip to a directory with read and write permissions.
4. Create a gRPC client.

Building Locally

If you're looking to build the grpc-device repo locally, look at the Getting Started section of CONTRIBUTING.md.

Running the gRPC Server

The server's startup configuration is set by specifying port and security settings in a JSON configuration file. A default configuration file named server_config.json with an insecure configuration (no SSL/TLS) is located in the same directory as the server executable. For more information on SSL/TLS related security settings refer to the SSL/TLS Support section. The location of the server binary is not important as long as the user has proper permissions in the chosen directory.

There are two ways to start the server:

1. Launch the server application without specifying a path to a configuration file (use the default configuration file):

   Windows

   .\ni_grpc_device_server.exe

   Note: It is also possible to start the server by double-clicking the executable. Starting the server through a command prompt, however, allows for observation of startup errors.

   Linux and Linux RT

   ./ni_grpc_device_server

2. Launch the server application by specifying a path (relative or absolute) to the configuration file:

   Windows

   .\ni_grpc_device_server.exe C:\path\to\config\file\server_config.json

   Linux and Linux RT

   ./ni_grpc_device_server /path/to/config/file/server_config.json

If the server starts successfully on the port specified in the configuration file, then it will print a message to the terminal output:

Server listening on port 12345. Security is configured with insecure credentials.

Note: If port 0 is specified then the server will automatically select a port from the dynamic range. The port used will be reflected in the startup message.

If the server fails to start (i.e. a port is not specified in the configuration file) then an error message is printed in the terminal and the application will exit.

Common Server Startup Errors

1. The datatypes of the values in the configuration file don't match the expected datatypes. For example, the port must be an integer type and not a string. The error message will provide specific details on the type requirements.
2. The configuration file can't be found at the provided location. This error can also occur if the user lacks read permissions for the file.
3. The server configuration file is malformed and is not in proper JSON format. Refer to the JSON configuration file in this readme for an example of the expected format.
4. The specified address is not valid. The solution is to select a valid IPv4 or IPv6 address.
5. The specified port is out of the allowed port range. The solution is to select a port in the allowable range (0-65535).
6. The specified port is already in use. The solution is to select another port or terminate the other application using the port.
7. Security configuration errors. See Server Security Support wiki page.

Default Configuration File (localhost):

Below are the contents of a default configuration file accepting localhost connections on port 31763 and configured without SSL/TLS. A configuration file with these contents also exists in the same directory as the ni_grpc_device_server binary.

{
    "address": "[::1]",
    "port": 31763,
    "security" : {
       "server_cert": "",
       "server_key": "",
       "root_cert": ""
    }
 }

Bind Address Support

The server supports specifying the address to bind to. The address can be used to enable local or remote connections. Address values include any valid IPv4 or IPv6 address. To bind to local (loopback) connection, specify address "[::1]". To bind to any address, specify address "[::]". If no address is specified, the server configuration defaults to any address "[::]".

Creating a gRPC Client

Each supported driver API has a corresponding .proto file that defines the interface used by clients to interact with the NI devices connected to the server. Creating a client requires compiling the .proto into supporting files in the client's language of choice using the protocol buffer compiler protoc. For more detailed information refer to the Creating a gRPC Client wiki page.

SSL/TLS Support

The server supports both server-side TLS and mutual TLS. Security configuration is accomplished by setting the server_cert, server_key and root_cert values in the server's configuration file. The server expects the certificate files specified in the configuration file to exist in a certs folder that is located in the same directory as the configuration file being used by the server. For more detailed information on SSL/TLS support refer to the Server Security Support wiki page.