High speed Ethernet

[rebayat]

Hi!
I want to control and also send digital speech data using ethernet standard. From what point should I start?
I have some experience in the field of telecommunications and plc programming.
I would mention that I want to build my own complete system.

 

[LadderLogic]

Do you want to do this in an industrial application?
I don't think PLCs are good for that... The available memory for most brands measures in tens of kilobytes. And the speed... The fastest PLCs scan time is about 2 milliseconds. If you prepare all your data (the standard Ethernet packet size is 1536 bytes, if I am not mistaken) and execute "network send" command within a single scan, how much time would it take you to send the whole speech pattern file? That's at least hundreds of kilobytes, isn't it? Not to mention that preparing your data would involve a lot of "byte pushing" - not unlike programming in assembly language. This certainly would be a challenging task, but is it worth it?

As much as I dislike using a PC to control machinery (this is what PLCs are for), I should say that handling sound and speech files is exactly for it. Or for a Mac

P.S. an off-topic: there was some trouble in your country recently... hope everything will end up for the best for everyone.

 

[hickman]

Ethernet hook-up

You can readily attach ANY serial or USB device directly to ethernet using a serial-to-ethernet or USB-to-ethernet device server. Look atDigi for these. They have a product called SerialAnywhere. It is software that assigns a virtual COM port to an IP address. Therefore, you can access the serial or USB device like it was attached to your computer.

Hope this helps.

 

[wevans]

as I have also worked as a millwright/electrician
and have a CCNP in telecomunications

I don't believe the ethernet and DH+ standards are the same

Ethernet is contention-based ( where each stations vias for time on a network )
While DataHiway Plus is non contention based ( hence the unlimited cable length in most PLC networking applications )

then again, I could be mistaken as I often am

 

[xrf123]

Voice over IP is a fairly common phone technology. The commonest PLC type data over ethernet is Modbus tcip, both will happily run on the same ethernet backbone together.

But 1 technology for both, I think is out. Voice is fast and high volumes of data but error checking is limited, PLC data slow small volumes and good error correction.