PLC and PC Connection 2

But you didn't think it relevant to even mention the actual brand and model of the PLC?

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IRstuff, Thank you for your reply. Siemens S7 PLCs are my target. What is the difference between the CP5611 communication and the OPC server communication software? How can I get the Velocity of every axis in a 3-axis machine?

Shouldn't your talk to your Siemens applications engineer for this?

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I am asking about communication ways between a PLC and a PC. What is the difference between the CP5611 communication and the OPC server communication software?

I believe that the CP5611 is a Network Interface Card, NIC or a piece of hardware which is used to connect a computer to an Ethernet network. OPC communication software is software running on a computer which might use a NIC to connect and talk to a PLC.

Hi farzad89:
In reading this string of replies, I was disappointed IRstuff's reply to you. I thought oh, if you give him brand, he can answer. Then you gave him brand and just replied [ask Siemens, not me]. I thought if he is spending time replying, he might offer us some insight and looking forward to learning from him. As you probably did too.

Disclaimer: I have not worked with CNCs for over a decade.

djs is correct, the CP5611 is the PROFIBUS network communication card. The short answer to your question is you want to do the velocity monitoring in PC (CNC) not PLC. So OPC would be easiest if you needed to record history of velocity, but you will have sample frequency rate limitations (network and read/write delays) in this kind of high speed monitoring. Script writing directly NC to grab sample, max/min and avg would allow a more high speed sample rate, and I would think siemens already has that diagnostics built in.

If you are just wanting to optimize the speed and velocity controller of the selected machine axis and not so much record history of velocity, you can use built in software/screens.

You lookup in your particular Siemens CNC model commissioning manual. Like MD32810 $MA_EQUIV_SPEEDCTRL_TIME (Or call Siemens as IRstuff puts it, if you want to go the more complicated and higher frequency velocity monitoring rate.) As there is a lot of machine data points in a CNC, the exact details of what you want to do and why; will dictate complicity. for example you may be wanting data directly from encoders, or may want MD34070 $MA_REFP_VELO_POS (reference point positioning velocity), MD34070 $MA REFP_VELO_POS (target point positioning velocity), you may have to account for backlash if movement points in different directs, etc. etc.

Go to manual section on Axis monitoring functions (dynamic)", also reference Function Manual, Basic Functions; Velocities.
To monitor live "Diagnostics" operating area → Menu forward key → "Axis diagnostics" → "Service axis"

Hope this gives you a little more to go on, or helps is some little way.

Don
BIN Industrial & PLC Training