Question about mixing media on DeviceNet

Hello

This is my first post on this forum, so bear with me. I'm working with a DeviceNet system where there needs to be a transition on the trunk line from the flat cable to the thick round cable. There is a point in the network where using the thick round cable would be more efficient and easier to use. What's the easiest way to make this transition physically? What connections would need to be made? I've tried to find a clear cut way to do this but haven't come across anything. I'm pretty new to DeviceNet in general so maybe I'm missing something?

Thanks for your help

Garrett

Something like this perhaps ?

ghl123 said:

I'm pretty new to DeviceNet...

Click to expand...

Get a free account on Rockwell website and read this technote:

TN44883 DeviceNet Book of Knowledge 01/22/2013 Edition (Access Level: Everyone)

At the bottom you will find a pdf document. That's everything you always wanted to know about DeviceNet but were afraid to ask.

ghl123 said:

Hello

This is my first post on this forum...

Click to expand...

Hi and Welcome to the Forum!

ghl123 said:

...there needs to be a transition on the trunk line from the flat cable to the thick round cable...What's the easiest way to make this transition physically? What connections would need to be made?...

Click to expand...

See here for connection options...

22526 - Connecting Round to Flat DeviceNet Trunk
Access Level: TechConnect

And here for considerations in maximum permissible cable lengths when mixing media types...

18119 - Mixing Media Types on a Trunk Line
Access Level: TechConnect

If you cannot access those technotes then please let us know.

Geospark said:

Hi and Welcome to the Forum!



See here for connection options...

22526 - Connecting Round to Flat DeviceNet Trunk
Access Level: TechConnect

And here for considerations in maximum permissible cable lengths when mixing media types...

18119 - Mixing Media Types on a Trunk Line
Access Level: TechConnect

If you cannot access those technotes then please let us know.

Click to expand...

I'm unable to see these links. I have an account already on here but not techconnect.

Ok, maybe this will help...



For the cable lengths on the Trunk Line you should be using the recommended lengths for the lower rated cable of the mixed types. In your case the Flat media is the more stringent of the two with regard to maximum lengths...

Flat Cable:
420 meters at 125 kbit/s
200 meters at 250 kbit/s
75 meters at 500 kbit/s

Thick Cable:
500 meters at 125 kbit/s
250 meters at 250 kbit/s
100 meters at 500 kbit/s

Example:

The new Trunk Line section using the Thick Cable is 100 meters in length.

The DeviceNet baud rate is currently 500 kbit/s.

The limitation for Thick Cable would normally allow a distance of 100 meters using 500 kbit/s if Thick Cable is all that is used for the entire Trunk Line. However, in this case the Trunk Line is primarily using the Flat Cable and a section of Thick Cable is being added in. Once there is mixed media the distance values for the lesser rated of the two must be used.

The Flat Cable is only rated for 75 meters at 500 kbit/s. So the Thick Cable should not be run any further than 75 meters between the two termination points while using 500 kbit/s baud rate.

If you are only going a relatively short distance with the Thick Cable, or are using a slower baud rate, then this limitation might not affect or apply to your modification. Either way, the above example is just intended to point out this important consideration when adding or replacing DeviceNet media.

Also pay attention to the Drain to V- options in the above wiring options.

Regards,
George