Hi All

I'm tasked to come up with the application as below using LOGO, but i have unfortunatly very less  knowledge.

The input will be an Hall effect sensor installed on an rotation axle.

Abrev.: SP = Measured speed , RL = relay output, X = let say 45km/h

The working scheme :

• At start up RL shall be activated for 4 – 7 sec.

• When SP > X for > 30 sec, when SP < X for > 5 sec, RL is activated during 4 – 7 sec.

• When SP > X for < 30 sec, when SP < X, RL shall be activated immediately during 4 – 7 sec.

I thank you already for your help.

Kakiek

Hi All

I'm tasked to come up with the application as below using LOGO, but i have unfortunatly very less  knowledge.

The input will be an Hall effect sensor installed on an rotation axle.

Abrev.: SP = Measured speed , RL = relay output, X = let say 45km/h

The working scheme :

• At start up RL shall be activated for 4 – 7 sec.

• When SP > X for > 30 sec, when SP < X for > 5 sec, RL is activated during 4 – 7 sec.

  
  

• When SP > X for < 30 sec, when SP < X, RL shall be activated immediately during 4 – 7 sec.

I thank you already for your help.

 Hello,

LOGO! 0BA6 - 7 - 8?

Have you already seen in the example? Or have you searched in the site Explorer above?

LOGO! Application Examples - PLCs - Siemens

some like this:

Logo speed control - Entries - Forum - Industry Support - Siemens

Hi Ste36,

thanks for your reaction.

I will use an 0BA6.

I have tried the whole day while using as basis the example you indicated me.

But I'm struggling for acknowled the SP >X during atleast 30 sec and when SP fall down below X for at least 5 sec and if condition fullfiled activation of RL.

Hi ixo65,

thank you for sending me a possible solution.

On line 1 everything is ok till after the timer. Once the timer (30 sec) has readched the 30 sec time and the speed is still above the 45km/h the output shall not be activated.

The output shall only be activated for 4 – 7 sec.when the speed drop down below the 45km/h for 5 sec.

On the otherhand when the speed is higher as 45 km/h for less as 30 sec (or other value), and the speed drop down below the 45 km/h the output shall be activated immediatly during 4 – 7 sec.

Hope this will clarify my needs,

B. Regards,

Hello Kakiek,

Reading the requirements, I write the conditions. Something sounds wrong, because there is a conflit. Please, adjust them.

What is RL and how it works?

FIRST CONDITION   (STARTING TIME)     RL = 1 (time 4 to 7 seconds)

SECOND CONDITION (AFTER STARTING TIME)

IF SP > 45 (time > 30 seconds) OR  SP < 45 (time > 5 seconds), THEN RL = 1 (time 4 to 7 seconds)

IF SP > 45 (time < 30 seconds) OR  SP < 45 (time = 0 seconds), THEN RL = 1 (time 4 to 7 seconds)

In the other hand, it seens that you really need to maintain the speed just around 45 km/h. The best way is to use a PI controller function.

See you

Hi Dinos,

thank you for your reaction.

I have made a working diagram, hope it will clarify the way to a solution.

Hello Kakiek,

The timing diagram is very clear. I will work in that.

See you

Hello Kakiek.

Attached a program to speed control.

In the picture that you sent, we have four situations.

1. I considered buttons to start and stop.

2. For a time less 30 seconds, there is no way. Less then 30 seconds can be any time between zero to 30. I considered "More than 15 seconds" and maintained "More than 30 seconds".

3. Also there is a situation which the RL doesn´t change its state when the speed goes down and goes up during a interval less then 5 seconds. I maintained (third condition).

Please take o look. May be something must be modified according your requeriments.

I hope it helps you.