Devicenet is series communication or parallel?

Hi all,

Actually i'm having this doubt for longtime. But I cant get to know till now from any website. May be its funny but I really and clearly want to know. The doubt is,

Devicenet communication is series or parallel?
Controlnet communication is series or parallel?

I'm thinking that both devicenet and controlnet are series communication and ethernet is parallel..!

It really doesnt matter to you as an enduser of one of these network standards.

But anyway, devicenet, controlnet and ethernet are all 'serial' network standards. That is the data is transferred one bit at a time. I dont think there exists a current network standard that transmit data in parallel.

About ethernet versus devicenet and controlnet.
devicenet and controlnet are half-duplex type networks. That means only one node can "speak" at a time.
ethernet is (today) a full-duplex type network. That means each node can both "speak" and "listen" at the same time.

Maybe that is what you meant with "serial" vs. "parallel".

JesperMP said:

But anyway, devicenet, controlnet and ethernet are all 'serial' network standards. That is the data is transferred one bit at a time. I dont think there exists a current network standard that transmit data in parallel.

Click to expand...

To expand on Jesper's answer, a 'noise issue' with parallel is called inter-symbol interference (how's that for pulling it out of my tail-feathers?). Because the wires are right next to each other, each data line would induce a little bit of current into the other conductors (also called crosstalk). the net effect is that each symbol (set of data bits) gets 'blurred', reflected into the next symbol, and generally create a bunch of havoc over longer distances. With the mutual inductance, and stray capacitance of the conductors, this also creates a lower bandwidth connection. If you've ever dealt with the internet, you know that a better bandwidth gives a better bit rate.

Y'all didn't think I had that many words in me, right?

JesperMP said:

But anyway, devicenet, controlnet and ethernet are all 'serial' network standards. That is the data is transferred one bit at a time. I dont think there exists a current network standard that transmit data in parallel.

Click to expand...

Actually u r talking about the transfer of signal along a communication cable. what i'm asking is, Is the entire devicenet network series or parallel? Let me clear you,
If I'm connecting 5 devices through devinet communication or 5 processors through controlnet communication and if any one of the cable damaged, my total network got affected. but it is not so in ethernet..
By the way, thanks for that halfduplex and fullduplex information.

Ah! The light turns on!

Serial and parallel are one way of looking at it, but the correct terms would be 'bus' and 'star'. These are terms that refer to netowrk topology

Sorry for the confusion!

DEEBAN T said:

If I'm connecting 5 devices through devinet communication or 5 processors through controlnet communication and if any one of the cable damaged, my total network got affected. but it is not so in ethernet..

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The reason that a single cable error will not bring down the entire ethernet network, is because today it is assumed that all connections must pass over a switch. An ethernet switch isolates each port from each other and thus the cables from each other.
For devicenet you can actually create segments to contain an error if you place repeaters at strategic positions.
For controlnet I dont think there exist repeaters. I may be wrong though.

Ethernet started originally without switches and repeaters, and one error could bring down the whole network.

JordanCClark said:

Ah! The light turns on!

Serial and parallel are one way of looking at it, but the correct terms would be 'bus' and 'star'. These are terms that refer to netowrk topology

Sorry for the confusion!

Click to expand...

Wah! U turned my light ON.. U got the point. Thank U. Thanks a lot for telling me the exact technical name (Network topology) and sorry guys for making u confused

Thanks Mr.JesperMP for the useful information..