Accumulator in Simulink

Question

I have a MATLAB function block in simulink and for each step simlulink does I want to input a counter with increment 1. Ex: 1st Step -> Acc=1 2nd Step -> Acc=2

I tried using a Count up block + Pulse generator but the time step of simulink is not constant.

Any ideas?

You need to add the code (and check formatting) that you have tried already. and also explain the results that you see (ie what's going wrong). — simo.3792
Simulink chooses a Variable Step Solver by default for you. If you want the steps to be equally distant in time, choose a Fixed Step Solver and specify the timestep instead, but know the implications of this in your model. If you want a block to be executed with a fixed periodicity, choose a Sample Time for it instead, or sample it with a Zero Order Hold, for example. — Manex
I'm not sure how you tried using the Pulse Generator, but isn't there a way to use the Pulse Generator so that the pulses are in sample hits rather than simulation time? Anyway, the method I used for counting hits is to use a C++ S-function, and then have a PWork vector that counts the calls. PWork is sort of a variable that stays persistent in memory. So, you append it at each function call and get the job done, regardless of solver used. — user2215426

Saharsh Bishnoi Saharsh Bishnoi · Accepted Answer · 2014-12-17T00:18:29

A common way to do this is to use a sum and a memory block with an initial condition of 0. It should count steps in both fixed and variable step simulations. In fact I believe this would be build and perform very much like an s-function solution during simulation.

Accumulator in Simulink

2 Answers