1) Simulink Plugin models:

When using a Simulink plugin model, the model is compiled using the Simulink Coder. Since the compiled code is linked with the CarMaker executable we can directly access any global CarMaker variables using the "From CM Var" block.
Make sure to check the Reference Manual for the available variables!

2) CarMaker for Simulink ("CM4SL") co-simulation:

When using CM4SL, the "From CM Var" block can not be used inside the Simulink model (for example generic.mdl).

If we want to read the C code variables in CarMaker for Simulink, we need to define the C code variables as new User Accessible Quantities (UAQ) in User.c in Project Folder > src_cm4sl. After compiling we can use the "Read CM Dict" block to read the new defined UAQs in Simulink.

In this solution we will take the c code variable "TSignSensor[0].Sign[0].suppl[0].val[0]" as an example. We can find this variable in C:\IPG\carmaker\win64-9.1.1\include\Vehicle\Sensor_TSign.h.

Preparation:

1. Generate a project with src_cm4sl folder. (check option "Sources / Build Environment")

2. Open the Makefile in src_cm4sl folder, comment out the two lines in the screenshot, enter the correct Matlab version and home directory:

Steps:

1. Include the Sensor_TSign.h header file in the User.c file:

2. In the User_DeclQuants() function, add the following line:
DDefFloat (NULL, "TSS_Supply_Value", "", &TSignSensor[0].Sign[0].suppl[0].val[0], DVA_None);
This defines the C code variable "TSignSensor[0].Sign[0].suppl[0].val[0]" as a new quantity "TSS_Supply_Value". DDef* are C functions to add variables to the User Accessible Quantities. You can find more information in the Programmers Guide > Integrating C-Code Models > C-Code Function Reference. 

3. Open msys and locate to the src_cm4sl folder then compile by executing "make":

4. After compiling successfully, we can read the new quantity "TSS_Supply_Value" in CarMaker for Simulink using the"Read CM Dict" block. The newly created UAQ will also be available in IPGControl.