OPAL-RT Asynchronous Process

Important: This node type is deprecated and will be soon replaced with a synchronized variant based on Shared memory.

The communication between OPAL-RT models and VILLASnode is established by using asynchronous programs. Asynchronous programs are are a feature of RT-LAB. They are used to exchange data between Simulink models and custom C programs. There are two ways to exchange sample values with an OPAL-RT simulator:

1. Use our adapted version of OPAL-RT's AsyncIP example for asynchronous processes (see OPAL-RT Asynchronous Process (AsyncIP)) In this mode, OPAL will send sample data via UDP to VILLASnode. VILLASnode has to use the Sockets node-type.
2. Run VILLASnode as an asynchronous process itself. This is a highly experimental feature and implemented in the node-type opal. It requires a 32-bit version of the villas-node. Data exchange is then handled using OPAL-RT's libOpalAsyncApi. This settings of this node-type a described on this page.

Prerequisites

This node-type requires libOpal{AsyncApi,Core,Utils}.

Implementation

The source code of the node-type is available here: https://git.rwth-aachen.de/acs/public/villas/node/blob/master/lib/nodes/opal.cpp

Configuration

Every opal node supports the following special settings:

send_id (integer)

recv_id (integer)

reply (boolean)

Example

nodes = {
        opal_node = {                                   # The server can be started as an Asynchronous process
                type    = "opal",                       # from within an OPAL-RT model.

        ### The following settings are specific to the opal node-type!! ###

                send_id = 1,                            # It's possible to have multiple send / recv Icons per model
                recv_id = 1,                            # Specify the ID here.
                reply = true
        },
        file_node = {
                type    = "file",

        ### The following settings are specific to the file node-type!! ###

                uri = "logs/input.log",                 # These options specify the path prefix where the the files are stored
                
                in = {
                        epoch_mode = "direct"           # One of: direct (default), wait, relative, absolute
                        epoch = 10                      # The interpretation of this value depends on epoch_mode (default is 0).
                                                        # Consult the documentation of a full explanation

                        rate = 2.0                      # A constant rate at which the lines of the input files should be read
                                                        # A missing or zero value will use the timestamp in the first column
                                                        # of the file to determine the pause between consecutive lines.
                        
                        buffer_size = 1000000

                        eof = "rewind"  # One of: rewind, exit (default) or wait
                },
                out = {
                        flush = true
                        buffer_size = 1000000
                }
        }
}

Arguments for OPAL-RT block

RT-LAB already provides a block to establish simple TCP/IP communication: ??? This block is based on a more generic block used for aynchronous programs: ???

Todo:

Insert name of RT-LAB blocks.

Param	Description	Example Value
FloatParam[0]	Protocol
FloatParam[1]	RemotePort	10200
FloatParam[2]	LocalPort	10201
StringParam[0]	RemoteAddr	192.168.0.10
StringParam[1]	LocalAddr	192.168.0.11
StringParam[2]	InterfaceName	eth2

Todo:

Complete documentation for the OPAL-RT Simulink module.