L
> Briefly, however, DDE or dynamic data exchange is a crude system for sharing
> and updating data between applications (typically) under Microsoft Windows.
> <clip>
>
> OPC formerly defined Object Linking and Embedding (OLE) for Process
> Control <clip>
I'm just curious. I remember when OPC came out, one of the big new "wonders" over DDE was that "it's binary, not ASCII". When OPC starts using XML & everything reverts to ASCII again, how much of a "step backwards" is this? Or is CPU power now so cheap we shouldn't care?
I don't know the size of average OPC-XML packets, but I know with UPNP (Soap + XML) it takes about 1500 bytes to turn on a single bit in a device, whereas something like Modbus/TCP would require 12 bytes to do the same.
Thanks - Lynn
> and updating data between applications (typically) under Microsoft Windows.
> <clip>
>
> OPC formerly defined Object Linking and Embedding (OLE) for Process
> Control <clip>
I'm just curious. I remember when OPC came out, one of the big new "wonders" over DDE was that "it's binary, not ASCII". When OPC starts using XML & everything reverts to ASCII again, how much of a "step backwards" is this? Or is CPU power now so cheap we shouldn't care?
I don't know the size of average OPC-XML packets, but I know with UPNP (Soap + XML) it takes about 1500 bytes to turn on a single bit in a device, whereas something like Modbus/TCP would require 12 bytes to do the same.
Thanks - Lynn