SINAMICS Hardware Limit Switch

Dear all,

We have a SINAMICS S110 CU305 PN servo controller and we need to add two hardware limit switches to it.

When one LS is activated, motor should be able to run in opposite direction. 

I've tried safety functions, but these functions stop the motor in both directions. 

We need a LS for positive direction and one for negative direction.

We are using S7-1500 and SINA_POS function block. So we have to use Telegramm 111.

I've already seen the parameter p2570. But I'm not sure if this is the correct solution for our problem or not. Even if this is correct, I'm not able to change that, because of telegram 111 I think. 

Any help will be appreciated. 

Technology Team

Hello,

there is no hardware switch reversal function for "normal" operation (only for active homing function). Hardware limit switches stop the drive and disable it.

I would recommend to define the software limit switches as well. In case of running into a SW limit switch the drive stops but stays enabled. You will get a feedback and you can return by PLC program.

Thank you for your answer. So I have to use software limits with position and with limit switches connected to PLC.

Our second problem is Intermediate stop with another limit switch. As long as this LS is triggered, motor shouldn't move and when LS is released,  motor should continue its last move. 

In SINA_POS function block, we have these one bit: "Intermediate Stop" that does exactly what I described. 

Now my question is: is this bit available through expert list in drive?

If it is available and if I can connect the HW limit switch to it, our problem will be solved. But I couldn't find the correct parameter. 

I could just find p2640 but it's connected to telegram 111 and used for SINA_POS.

Should we connect this limit switch to PLC and control the stop function in software, or we can do it in HW?

Thank you for your help.

Technology Team

Hello,

the "intermediate stop" is parameter p2640. If you want to change it from the telegram binector r2090.5 to a digital input, you can set p922 = [999] (free bico). So it is possible to change the connection on p2640.

Thank you for your answer.

We use Telegram 111 to communicate with SINA_POS.

If I change p922 to free BICO, are we still able to communicate with it?

If yes, what should I change in PLC  hardware configuration?

Thank you again. 

Thanks for your help. 

I will test it and write the results. 

Hi,

I know this forum is for a long time ago.

I just come here to write the results of my test and ask a question ;-) 

I changed Telegramm to 999 and connect the "Intermediate Stop" to an input bit. It works as expected.

Now, I go back to my first question about limit switches.

As far as I understand, I cannot use HW limit switch and Safety Integrated for my purpose.

So I have to use Software LS (Position feedback) or "EPOS stop cam". (Drive is configured as Basic Positioner)

I need to activate stop cam first. To do this, I activated p2568 (BI: EPOS STOP cam activation) then connect my limit switches to p2569 (BI: EPOS STOP cam minus) and p2570 (BI: EPOS STOP cam plus)

Everything works as expected, except one!

When motor reaches the limit switch (e.g. plus direction), it stops and cannot move anymore in the same direction (plus). Then an error msg shown.

When I acknowledge this error, motor can move in opposite direction (minus direction). So far everything is good.

Problem occurs when I need the motor to move in plus direction again. It always shows an error msg and motor won't move anymore in plus direction.

It means after the activation of one limit switch, I am always able to move the motor only in opposite direction. Even when the motor is far from the limit switch and LS is not activated anymore.

I guess something like latch function is running on the drive, or the way to acknowledge this error is different than other errors...

PS: For acknowledge I use Ack input of SINA_POS function, or "Acknowledge All" button on Alarm window of Starter.

Thank you for your time.

Any help will be appreciated.

This text from S110 List Manual, describes exactly my problem. But I cannot find a solution for it. Also I don't understand the yellow part:

Is it possible for you to share the project ?