Programmatically change user defined Library objects in Simulink model

Dear Sirs,

I have made a plain Simulink model consisting of Current Sensor/Scope/Switch etc. There are also two subsystems (Load and Battery) that are user defined Library objects. Links looks fine. The model works and simulation results are correct.

Now I want to programmatically (from Matlab command window) change the Library objects. Say from Load_RLC to Load_R. Both exists as Library objects. I have tried commandos like:

open_system('LowVoltageSystem')

add_block('Load_R','LowVoltageSystem')

pos=get_param('Load_RLC/LowVoltageSystem,'position')

delete_block('Load_RLC/LowVoltageSystem’)

set_param('Load_R','position',pos)

But the ‘Load_R’ can not be found (There is no block named 'Load_R')

I have also tried things like:

replace_block('LowVoltageSystem,'Load_RLC','Load_R')

Here the ‘Load_R’ is invalid block type.(Invalid NewBlock (<Load_R>) passed to REPLACE_BLOCK. Try built-in/BLOCKTYPE or a valid block name.)

The replace_block command, however, works with the built-in library blocks.

If I change the library components ‘manually’ everythings works, so there is nothing wrong with the components themselves.

What am I doing wrong here?

Best//Gert

Answer 1

[Fangjun Jiang]

In the first part of your code, add_block() is not used properly. You need to specify the full path of both the source and destination blocks. Look at examples in "doc add_block".

replace_block() is the ideal function to use for your task. Again, you need to specify the full path of the source and desination blocks, e.g. 'CustomLibraryFile/LibraryBlock', 'ModelFile/ModelSystem/BlockName'. For custom library, you also need to open the library first using open_system() or load_system()

[Gert Persson]

Maybe there is something that I do not understand when it comes to description of path?

Block name still seems not valid?

[Fangjun Jiang]

The full path of a block is 'ModelFileName\SystemBlockName\BlockName'.

However, replace_block() requires this info in a slightly different way. Look at the examples in "doc replace_block"

Most likely:

replace_block('LowVoltageSystem','Name','Load_RLC', 'Load_R/Load_R')

[Gert Persson]

You are perfectly right!

I will make the model more clear by renaming the load in 'LowVoltagesystem' to 'Load'. I will also put the load in a library 'Load_Lib'. The command must then become:

replace_block('LowVoltageSystem','Name','Load', 'Load_Lib/Load_R')

Following the LibraryLink of the Load in the Simulink model 'LowVoltagesystem' then shows what Load is active.

If I remember right there was also an option for closing the "Replace Dialog" that appears. Nice things todo tomorrow :-)

Thanks a lot for your professional help!

[Fangjun Jiang]

To suppress the dialog box from being displayed, add the 'noprompt' argument as the last argument in the command.