siemens S7 problem 1

[kw67]

I am currently working on a project using a Siemens S7 300 P.L.C CPU315 -2dp, (I have very little experience with S7). I am trying to control a motors speed from an incremental encoder. The motor is driving a paper reel, spooling from one reel to the other as the reel circumference gets larger the linear speed of the paper is increasing which I don't want. On this P.L.C I have one digital input card, one digital output card, one 8 channel analogue output card and one 8 channel counter module. The motor is being driven by an S.E.W Movidrive VSD. The encoder is connected to a wheel on the paper. what functions within S7 software can anyone suggest I use to get this to work. A quick response would be appreciated as I have got to get this woking for Sunday Morning 23rd.

 

[Skogsgurra]

I am sorry that I have to be rude and blunt with you.

This kind of reel-to-reel drives need quite a lot of experience with diameter servos and often also special hardware to evaluate the line speed encoder and the shaft speed encoders. It is a demanding task and if someone asked you to have this running by Sunday morning without even having analysed what you need to do the job - I can only say that I feel sorry for you and your boss.

The best thing to do is to get in touch with a specialised company or consultant. Siemens or SEW can probably help you to find a suitable company.

The next best thing to do is to postpone the start-up and do some thorough homework. After that, you can do the job yourself. But be prepared to add some more hardware if the SEW drive doesn't have the diameter servo and the necessary encoder inputs in the drive.

Anyhow, you have to talk to your boss about this. Do not wait and hope.