Troubleshooting Multicore External Mode
R2026bConnection Fails on CPU1 or CPU2
Description
Monitor & Tune on a CPU1 or CPU2 model times out, or displays a "No server
connected" message.
Action
Start external mode on the CM4 model before starting CPU1 or CPU2. Verify that the CM4
model status indicates that the application is running. Run
helperValidateMulticoreExtMode and verify that the IPC channel
assignments in the C28x models match the corresponding settings in the CM4 gateway
model.
Connection Fails on CM4
Description
Monitor & Tune on the CM4 model times out.
Action
Verify that the host computer and target hardware are on the same subnet. Verify with
ping 192.168.0.12. Ensure that the Ethernet cable is connected and not
faulty. Check that there is no IP address mismatch between model configuration and actual
target address. Ensure that a firewall is not blocking TCP ports 17725-17727 on the host
computer.
Multiple Errors Occurred After Stopping CM4
Description
You stopped the CM4 model while CPU1 or CPU2 was still connected, and errors appear.
Action
This is expected. Always stop C28x models before CM4. The CM4 gateway holds the TCP connection. When it stops, the host loses its route to CPU1/CPU2. Stop and restart all models in the correct order: Build CM4 → CPU1 → CPU2, Connect CM4 → CPU1 → CPU2, Disconnect CPU2 → CPU1 → CM4.
Build Fails with IPC Channel or Port Error
Description
Build produces an error about IPC channel conflict, port duplicate, or port reserved.
Action
Run helperValidateMulticoreExtMode to identify the misconfiguration.
Common issues include: two cores assigned the same IPC channel, TX and RX set to the same
channel on one core, IPC channel value outside the valid range 0-7, two cores assigned the
same TCP port, or a TCP Send/Receive block in the CM4 model using a port reserved for the
gateway (17725, 17726, or 17727).
IPC Channel Mismatch Error
Description
Build produces MulticoreIPCMismatch error.
Action
The IPC channel settings in the C28x model do not match the CM4 gateway settings. Open
both models, navigate to Hardware Implementation >
Target hardware resources > External mode,
and ensure the channel values are aligned. Run
helperValidateMulticoreExtMode to verify.
Signals Not Updating in Simulation Data Inspector
Description
External Mode is connected but no data appears in the Simulation Data Inspector.
Action
Verify that the Scope block is connected to the signal of interest. Check that signal logging is enabled by double-clicking the Scope block and verifying it is configured for External Mode logging. Ensure that the model status indicator shows “Running”. If the model is connected but the application has not started running yet, wait for the status to update.
