Hello,

how do you realize the positioning? Do you use the basic positioner function module (EPOS) inside the drive or do you use a technology object (TO positioning axis) inside the PLC?

Anyway it will be difficult to start a positioning by giving a setpoint position and a time. How do you want to do that? The positioning time is a result of the distance and the dynamic (v_max, acceleration and jerk). Why do you need to give the time for the positioning? Is there a relation to some other process? Or in other words: do you need synchronous operation functionality?

Hello,

in MDI mode you can change the override velocity for each positioning command. This would be a suitable way. 

If you want to have a flying change between your positionings you could also use the traversing blocks of the basic positioner. There you can define your different positioning movements (distance, velocity, acceleration) and also the condition how to go to the next command (flying or wait, etc.).

You should just try out the different methods, maybe to understand them and to find out which is the best for you. For testing the functions I would maybe recommend to not use the communication via PLC. You can try it out just with simulated I/Os on the S120 itself. This should be easier for the beginning.

Hello,

you can also use telegram 111. 

For further information regarding EPOS functionality like traversing blocks, you could also have a closer look in the function manual chapter 8.8:

https://support.industry.siemens.com/cs/de/en/view/109740020

As I described: If you use the traversing blocks you predefine your positioning motions in a kind of table and you just "start" these positionings in the table via the PLC then. The table itself is configured in the drive (distance, velocity, acceleration...).

If it should be more flexible for each positioning it is maybe better to use MDI mode and calculate distance, velocity override, acceleration override etc. during runtime in the PLC and send it via telegram 111 to the drive.

Hello,

this is not possible via the cyclic telegram communication, but each value in the traversing block table is in fact a parameter of the drive, so with an acyclic write command by the PLC you can also change the traversing block parameters via PLC.

Hello,

I don't know your application in detail, and this is also not necessary I think. I just wanted to show you the options:

1. using MDI mode (in my opinion this is what you should use)

2. traversing blocks (could be an option)

...but I don't know the wanted behavior of your machine. If you just have maybe like 2 or 3 fixed recipes for different positioning motions it could make sense to use the traversing blocks. If you cyclically need to change your positionings I would suggest MDI mode.

However: Which PLC and platform do you use? For S7-300/400 in Step7 V5.x there is a function block available (called FB283) that can handle MDI mode as well as acyclic communication for traversing blocks.

Here the link:

https://support.industry.siemens.com/cs/de/en/view/25166781

If you use TIA Portal there is the so called DriveLib available, which includes one FB for the EPOS (called SINA_POS - operating with Telegram 111) and also an FB for acyclic communication (called SINA_PARA). Here the link to this DriveLib:

https://support.industry.siemens.com/cs/de/en/view/109475044