Why can't I add a block to my model using add_block?

I want to add a block in a Simulink model named myModel.mdl. When I open the model and attempt to add a block using the following code:

open myModel.mdl

add_block('simulink/Sources/In1','myModel/myin1')

I sometimes receive the following error:

 ??? There is no block named 'simulink/Sources/In1'

Answer 1

[MathWorks Support Team]

The Simulink library must be loaded to programmatically add blocks in a model. The LOAD_SYSTEM function can be used to programmatically load the Simulink library as in this example:

load_system('simulink')

open myModel.mdl

add_block('simulink/Sources/In1','myModel/myin1')