UDP - Loopback
This example demonstrates how one Real-Time UDP Client and one Real-Time UDP Server communicate.
All UDP nodes are located in the same system and on the same Ethernet interface. This is achieved by assigning multiple alias-IP addresses to one Ethernet interface. With this setup, the UDP Client and Server are on the same physical Ethernet interface.
Setup
Prerequisites
You will require the following to run this example:
- Speedgoat real-time target machine with at least one unused Ethernet interface
Wiring of Target Machine
No physical wiring is required.
Ethernet Configuration of the Client and Server
Use the Speedgoat Ethernet Configuration Tool to assign the IP address to one unused Ethernet interface (on-board or IO71x/IO79x) on the target machine. The communication between the client and the server(s) on the unused Ethernet interface is performed over the localhost. No cable is required.
The IP address assigned should be 192.168.10.1. The netmask for this local address is 255.255.255.0. This IP is used as the gateway address for the client and server(s) in this example.
% Create target object and connect to target machine
% Configure the Ethernet interface for the ModbusTCP example
speedgoat.configureEthernet; % Open the Speedgoat Ethernet Configuration tool
Add the IP addresses of the client and server to the same Ethernet interface. Adapt the name of the interface according to your target machine configuration.
IP_Sender_00 = '192.168.10.10';
IP_Receiver_00 = '192.168.10.20';
InterfaceName = 'ETH1'; % Ethernet Interface on the target machine used for the example. Adapt this according to your target machine.
ipAliasObj = speedgoat.IpAliasConfiguration('TargetObject', tg);
ipAliasObj.add(InterfaceName, {IP_Sender_00,IP_Receiver_00});
Check the server Ethernet settings:
Initialize and Open the Simulink Model
modelName = 'sgMdl_UDP_Loopback';
Build, Download, and Run the Example
To run the example, either run the following code section or click the Run on Target button in the REAL-TIME tab in the Simulink model.
% Build the Simulink model
slbuild(modelName); % this will create the real-time application file (.mldatx)
% Create and connect to the Speedgoat real-time target machine
% Download the real-time application to the target machine and set stop time
% Start the real-time application and open the SDI-Viewer
%% Setup SDI to visualize signals
% Get and configure SDI Run
allIDs = Simulink.sdi.getAllRunIDs;
SDIRun = Simulink.sdi.getRun(runID1);
SDIRun.name = 'Real-Time Simulation';
% Clear and configure plot layout
Simulink.sdi.clearAllSubPlots
Simulink.sdi.setSubPlotLayout(1, 1); % layout with two plots
Simulink.sdi.setSubplotLimits(1, 1, "tMin", 0, "tMax", 5); % set time span to 10 sec
% Get signals by name (signal label in Simulink)
UDP_Receive_Signals = SDIRun.getSignalsByName('UDP_Receive_Signals');
% Assign signal to subplots
plotOnSubPlot(UDP_Receive_Signals.Children(1), 1, 1, true);
plotOnSubPlot(UDP_Receive_Signals.Children(2), 1, 1, true);
plotOnSubPlot(UDP_Receive_Signals.Children(3), 1, 1, true);
Simulink.sdi.setSubplotLimits(1, 1, "yMin", -5, "yMax", 5);
The output is then visible in the Simulink Data Inspector (SDI). You should see 3 different sine waves, like in the image below:
Restore Target Configuration
To restore the default configuration, you can simply reopen the Speedgoat Ethernet Configuration Tool and tick the Show Advanced Settings checkbox. Then click the Restore button in the bottom right.
This will erase the IPs of every Ethernet interface and set the host link IP to 192.168.7.5 and the netmask to 255.255.255.0.
We recommend restoring the default settings to reduce possible configuration errors.
Additional References