Article ID: 000083975 Content Type: Troubleshooting Last Reviewed: 12/01/2011

Driving Simulink Scopes With Complex Signals Gives Errors

Environment

    Quartus® II Subscription Edition
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Critical Issue

Description

You cannot drive Simulink scopes with complex signals. They only accept real signals (including real vectors). If you attempt to drive a scope with a complex signal in your design, Simulink assumes this signal should be real and back-propagates the real type through the design, until such time as there is a clash, where a block is explicitly driven by a complex type. This issue affects all configurations.This clash results in the following error message:

"Attempted to set output port (n) complexity after it was already set to opposite sense."

If you see this error for a complex port, check that the signal downstream is not driving a scope directly.

Resolution

Add a Simulink Complex to Real-Imag block (Simulink > Math Operations library) and connect the real and imaginary components to the scope individually.Blocks other than Simulink scopes may also cause similar errors, if they only accept real data types. The same workaround applies.This issue will be fixed in a future release of the DSP Builder advanced blockset.

Related Products

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Intel® Programmable Devices

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