Hi, 

I have a project that have developed over time. Its a home made hot tub that I have outside. It has a circulation pump, a heater and a pump to drain water from a pump well. 

All is running good now for many years. The next think i´m doing at the moment is to build a motorized cover. 

I have a 3-phase motor with gearbox, a Sinamics V20 frequence converter and two limit switches to control the cover. Start/Stop/Reverse is controlled by the DIs at the V20 and the speed is controlled with a potentiometer connected to the AI on the V20. 

I want to Open/Close the cover with the same button (1 physical button OR 1 soft button on the webpage)

The solution I have in the Logo! is something I just came up with from testing in the simulation mode. But my thought is that there must be a simpler/more clever way to program this?

Any tips or tricks for the program is appreciated. I always want to learn more :) 

Hello mlindeloef,

Your cover is but a very daring programming !!

Once a ride has been activated, it cannot be stopped !

If the lines of the limit switch are defective, the drive will never switch off !

And what do you do if someone is still sitting in the pool and the cover closes automatically or remotely ? (In any case, a safety bar is required!)

Finally, the question: How should the cover behave after a stop in the intermediate position? (Close, open or drive on ? This automatically or manually ?)

Your circuit will not be simpler, but if it is to be safe, more complex !

greeting Ella_68

 Thank you for you input! Alot of important things :)

For the safety I have an "emergency stop"-button at the control cabinet wich switch of the control power that then needs to be resetted. For the issue if someone is still in the pool I will have a "safety edge". like this:

To shut of the control power. That then needs to be resetted.

When thinking I must have some kind of "time out" for the movement. If it do not reach a limit switch in time.

The last point I have not thougt of. What happens if it stops between the switches.... That it something that needs to be implemented. Like if the emergency stop is actvated in the middle.

Ella_68

Hello mlindeloef,

Your cover is but a very daring programming !!

Once a ride has been activated, it cannot be stopped !

If the lines of the limit switch are defective, the drive will never switch off !

And what do you do if someone is still sitting in the pool and the cover closes automatically or remotely ? (In any case, a safety bar is required!)

Finally, the question: How should the cover behave after a stop in the intermediate position? (Close, open or drive on ? This automatically or manually ?)

Your circuit will not be simpler, but if it is to be safe, more complex !

greeting Ella_68

mlindeloef

 When thinking I must have some kind of "time out" for the movement. If it do not reach a limit switch in time.

A runtime monitor is certainly very good if the cover would block. As a limit switch I would take at least one with a break contact. If the cable is interrupted, the logo "thinks" that the end switching point has been reached. A limit switch with a changeover contact (opener/closer) is better. I would route this via an XOR. The meaning is simple: if there is an interruption, both inputs are =0; If there is a short circuit, both inputs will eventually be =1. This can be evaluated by the logo as a limit switch error.

Ella_68