Hey everyone,

Is there any way faster than the aquisition cycle of 100ms to read and write tags between a PLC1516 and a Unified PC RT?

Thanks in advance.

I thought it should be possible with the "add new" button when you select an update time. But it does not accept values below 100ms. So I think it is not possible.

But the first question that pops up in my head... Why?

>> You could of course make a FIFO form 10 values en poll this every 100ms and you could catch 10 value changes in that time

Thanks for your answer. In my case the fifo wouldn't help my process to be faster.

Once I can't reduce the aquisition cycle time I wonder if it might exist another type of communication faster than the S7connection.

First up a disclaimer, I haven't used any of the below referenced libraries yet and I don't know what the timing limitations are.

However, I saw this library which supports various communications methods including TCP/ UDP which in theory should get you closer to the metal so to speak.

https://support.industry.siemens.com/cs/document/109780503/libraries-for-communication-for-simatic-controllers?dti=0&lc=en-AU

Maybe you need to go to that lower level to achieve what you want.

There is a related streaming library if JSON/XML would work.

https://support.industry.siemens.com/cs/document/109781165/library-for-data-streams-(lstream)?dti=0&lc=en-AU

Also there is this library for more industrial type comms:

https://support.industry.siemens.com/cs/document/109779920/communication-support-packages-(csp)-for-wincc-unified-in-tia-portal?dti=0&lc=en-AZ

Let us know if you get a good result.

Hi guys, thanks for all the answers!

I am using the unified to consult some data from a customer db and return the data to plc to take a decision. I already got some satisfying results, but if I could make it faster would be awesome.

I think I will try to go with ro14 suggestion. I am a bit swamped with work but as soon as I can make the tests and have some results I return here to share.

Thanks again!