Frequency Measurement
This example shows how to measure input signal frequency by using Simulink® Desktop Real-Time™. The measured signal is connected to the counter input of your data acquisition board. Counter Input block is configured to reset counter each sample-hit after counter read. Dividing counter value by sample time gives input signal frequency.
Note: To run this model, you must have a data acquisition board with counter input connected to your computer.
Run Model in Connected IO Mode
- Open the Counter Input block and select your data acquisition board. If there is no board installed, install it by clicking the Install new board button. 
- To switch to Connected IO mode if needed, on the Desktop Real-Time, select Mode > Connected IO. 
- To start the real-time execution, click Run in Real-Time. 
Run Model in Run in Kernel Mode
- Open the Counter Input block and select your data acquisition board. If there is no board installed, install it by clicking the Install new board button. 
- To switch to Run in Kernel mode if needed, on the Desktop Real-Time tab, select Mode > Run in Kernel. 
- To start the real-time execution, click Run in Real-Time. 
The model builds, connects to Run in Kernel mode, and starts.
Open the Model
open_system('sldrtex_counter');

Close Open Scopes
close_system(find_system(gcs ,'BlockType', 'Scope'));
Clean Up Model
clear close all bdclose('sldrtex_counter')