OPAL-RT AsyncIP Example Format

VILLASnode supports the payload format used by OPAL-RT's AsyncIP example project shipped with their RT-Lab environment.

In the example project, the payload is defined by the following lines from the AsyncIP.c file as:

// ****** FORMAT TO SPECIFIC PROTOCOL HERE ******************************
//
// Define the structure of the data that we send out. This is used in the
// SendToIPPort function
struct data_out
{
  short  dev_id;             // (2 bytes) Sender device ID
  int    msg_id;             // (4 bytes) Message ID
  short  msg_len;            // (2 bytes) Message length (data only)
  double data[MAXSENDSIZE];  // Up to MAXSENDSIZE doubles (8 bytes each)
};
//
// Define the structure of the data that we receive. This is used in the
// RecvFromIPPort function
struct data_in
{
  short  dev_id;             // (2 bytes) Sender device ID
  int    msg_id;             // (4 bytes) Message ID
  short  msg_len;            // (2 bytes) Message length (data only)
  double data[MAXRECVSIZE];  // Up to MAXRECVSIZE doubles (8 bytes each)
};
// **********************************************************************

Implementation

The source code of the format-type is available here: https://github.com/VILLASframework/node/blob/master/lib/formats/opal_asyncip.cpp

Configuration

delimiter	string
real_precision	integer Default: 17 Output all real numbers with at most n digits of precision. The valid range for this setting is between 0 and 31 (inclusive), and other values result in an undefined behavior. By default, the precision is 17, to correctly and losslessly encode all IEEE 754 double precision floating point numbers.
ts_origin	boolean Default: true If set, include the origin timestamp in the output.
ts_received	boolean Default: true If set, include the received timestamp in the output.
sequence	boolean Default: true If set, include the sequence number in the output.
data	boolean Default: true If set, include the data in the output.
offset	boolean Default: true If set, include the offset between origin and received timestamp in the output.

{

• "delimiter": "string",
• "real_precision": 17,
• "ts_origin": true,
• "ts_received": true,
• "sequence": true,
• "data": true,
• "offset": true

}

Example Configuration

node/etc/examples/formats/opal-asyncip.conf

nodes = {
    node = {
        type = "socket"
        layer = "udp"

        format = {
            type = "opal.asyncip"

            dev_id = 99
        }

        in = {
            # Port number specified in Asynchronous Process block of RTlab project
            address = ":12000"

            signals = {
                count = 64

                # The Asynchronous Process block only supports floating point values!
                type = "float"
            }
        }

        out = {
            # IP address and port of OPAL-RT Target
            address = "192.168.0.44:12000"
        }
    }
}