Using set_param to change parameter DataTypes in Packet Input block does not work.

I am using the block Packet Input to receive CAN messages.

I have several of these blocks and I can change the parameter Sampletime by using this command:

set_param('.../.../Packet Input','SampleTime', '0.01')

However, when I want to change the parameter DataTypes it does not work:

set_param('.../.../Packet Input','DataTypes', 'double')

I get this error:

"Non-string expression where a string was expected."

Even though both parameters have the same properties:

>> ans.SampleTime

ans = 

            Type: 'string'
            Enum: {}
      Attributes: {'read-write'  'read-only-if-compiled'  'link-instance'}

>> ans.DataTypes

ans = 

            Type: 'string'
            Enum: {}
      Attributes: {'read-write'  'read-only-if-compiled'  'link-instance'}

How do I set the DataTypes parameter in the Packet Input block via set_param()?

Answer 1

[Sandip Kumar]

In order to specify the DataTypes, try using ''double'' instead of 'double'.

Thanks, Sandip, MathWorks

[Sandip Kumar]

That is a double-single quotes (instead of single quote) , in case it is not clear.

[Markus Nordstrand]

Aha I see now. It was almost right, in order for Matlab to interpret a single quote as a sign I have to write '' according to this, which means that if I want to send the string 'double' to the packet input parameter setting, I have to use '''double''', aka tripple single quotes.

This works! Thank you very much for the input!

/Markus