Timer to send a new message?

Hi all

I have a system with receiver and a triggered sender. When the receiver receives a new message it will trig the sender to send the next message.So if the message lost in their way to the receiver the system will hang forever.

I need a timer that wait the message for a specific period ( 1 sec ) , if no new message received the sender will triggered to send next message. of course this timer reset when receiver has a new message.

My receiver has a trigger out port that switches between 1 and -1

[Salaheddin Hosseinzadeh]

Oh! You should have mentioned simulink in your question.

I've no idea about simulink, I just know you can write a code and create a block from it.

Do your self a favor, add more details to your question and I'll remove my answer so that someone else find your question in unaswered section.

Good Luck!

[israa]

ok sorry for not mention that i'm using simulink, thanks a lot

Answer 1

[C.J. Harris]

I would probably use a resettable integrator for this task. Feed the integrator a constant value of '1', that way it will act as a timer. If the timer reaches a defined value (1 sec) send a message (then reset the integrator). If you receive a message, send a new one, and just reset the integrator to zero and it will begin counting up again.

Of course - there is always the option of using Stateflow for such a task.

[israa]

Can u please explain the part : " If the timer reaches a defined value (1 sec) ...." ?

does this mean i should use IF function block , because i use a Relational Operator block with '==' operator to compare the integrator output with a constant value (1 sec) but the output of the Relational Operator block is always false even if a message loss occur

[C.J. Harris]

You cannot compare a floating point number using the '==' operator, even if 1 is divisible by your time-step, it is still unlikely to trigger. Instead you should just check if the output from the integrator is equal or greater than '=>' 1.

[israa]

Thank you C.J. Harris, it's work now