why need signal conversion to assign a signal line?

hello everyone,

when I assign a signal line I meet the follow problem:

The Simulink signal object specified on the line originating from output port 1 of BLDDPM_cpu1_CCP_V1_0_20190818/Phase3_MC/current_measure_wind1/current_scaling_rated/Demux is invalid because it cannot be uniquely mapped to a valid signal in the model. Consider inserting a Signal Conversion block after the output port and specifying the signal object on the output of the Signal Conversion block instead.

what it means? actully when i use the Signal Conversion block before assigning my signal line, it works, I do not know clearly which ''because it cannot be uniquely mapped to a valid signal in the model'' means for?

I am looking forward your advice soon! thanks!

Answer 1

[Urmila Rajpurohith]

The ability to associate outputs of a “Demux” Block (containing multiple outputs) with “Simulink.Signal” objects is not available in Simulink.

Note that a “Demux” containing multiple outputs generates virtual signals. It is not possible to name, rename, or associate “Simulink.Signal” objects with virtual signals.

To work around this issue, convert the virtual signal to a nonvirtual signal. You can do this using any of the following:

• Signal Conversion block
• Data Type Conversion block
• Gain block whose "Gain" value specifies 1

The nonvirtual signal output by these blocks can be named or associated with a “Simulink.Signal” object.