The principle of DP communication

[Tom749]

I use the DP communication on running the PLC system with convenience. When I remember my past season it was so hard to connect the wire to the IO device in the long distance. It is so wonderful technology. So I want to know the principle of the DP communication as an engineer who use the convenience of the DP communication. Can I know the basic concept of the DP communication? I attach some picture of DP connection. Thanks for your help in advance. Edited October 30, 2011 by Tom749

[panic mode]

it is a 485 network (multidrop) with proprietary protocol. you can setup cyclic messages to update frequently used data (like I/O) or unsolicited message if something is used occasionally (change drive parameter for example). basic info and some links can be found on Wiki: http://en.wikipedia.org/wiki/Profibus

[TechEric]

I have not seen that round connector before. Also I did not realize it was RS-485 electrically. Thanks for explaning. Below is the connector I am familiar with, which can be found at http://www.icpdas-usa.com/products2.php?PID=3903 . The schematic with the swirch is of the connector. The female connector is on an IO device. I do not know if this is a typical IO device connector or brand specific. Edited November 1, 2011 by TechEric

[Joe E.]

The DE9 connector is fairly typical, in my experience. We use this one: https://support.automation.siemens.com/US/llisapi.dll?func=cslib.csinfo?=en&objid=6ES7972-0BB60-0XA0&caller=view We have a machine that has adapters to go from the DE9 to a round connector that is at least similar to what Tom749 posted.