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Adam303

Lifetime Supporting Member
Adam303
Join Date
Aug 2009
Location
Chicago
Posts
587
Hi guys. I have a 1756-DNB DeviceNet bridge and I'm trying to learn how to use the protocol. As you can read I'm totally new to DeviceNet and I'm eager to learn.
This is what I have so far
1756-DNB module
InterlinkBT conduit cover adapter BCA-57-M123
TURCK Status sensor
couple feet of belden 3082A devicenet wire
RsNetWorx for deviceNet

Can any one please help me set this protocol up so that I can reed the status of the sensor.
If there is more information needed please let me know.

Thank you for all the help.
 
The 1756-DNB as it's powered up shows No Network Power. I see that the device net port pin out shows V+ and V- should an auxiliary power be applied to those terminals or does the module it self provide power?
 
You have to put 24VDC to the network wires. They are not self powered.
Do a search on the AB website for the devicenet manuals or better still download the "Devicenet Book Of Knowledge" from the AB site.
Study this first and you will find it s lot easier.
Regards Alan
 
The first things I'd recommend for a DeviceNet novice are the DeviceNet media selection guide, the DeviceNet Book of Knowledge from RA, and the tutorial PowerPoint Slideshow that gets installed with RSNetworx for DeviceNet. Because you are using ControlLogix, the big DeviceNet Modules with Logix 5000 Control Systems manual will be useful too.

I've called the Media Selection Guide "the Moby Dick of technical manuals" because everybody knows it is important literature but virtually no one reads the whole thing. The Publication number is DNET-UM072.

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/dnet-um072_-en-p.pdf

The DNet Modules manual is a good summary of how DeviceNet modules work with Logix 5000 control systems. It doesn't address the less-popular MicroLogix 1500, SLC-500, and PLC-5 interfaces. The Publication number is DNET-UM004.

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/dnet-um004_-en-p.pdf

In the RA Knowledgebase, the big DeviceNet Book of Knowledge is a giant collection of technical notes, authored and maintained over the last 15 years by "Doctor DeviceNet", Bob Law of the RA Commercial Engineering department in Cleveland, Ohio. Bob taught me everything I know about DeviceNet.

http://rockwellautomation.custhelp.com/app/answers/detail/a_id/44883

The slideshow is quietly installed along with RSNetworx and does a good job of describing how the Scanlist Editor, the EDS-Based Parameter Editor, and the other parts of the software work together. Search the Program Files\Rockwell Software\RSNetworxii\ directory for *.PPS files. This slideshow hasn't been updated recently but it is good fundamental overview information.

Sometimes it's also helpful to get information from a non-Rockwell Automation source. The guys at Molex (formerly Woodhead Connectivity, formerly SST) have published very good vendor-independent articles on DeviceNet wiring, signalling, protocol, and troubleshooting.

And there's an industry association for DeviceNet; the ODVA. Many of the documents and summaries about DNet can be obtained directly from them. www.odva.org.
 
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Thanks again. I'll read up on the recommended literature and will post if I have any questions.
Thank You
 
Ok got a small question here. The manual states that I have to place a terminating resistor at each end of the truck line. Does that mean I have to place a resistor at the 1756-DNB?
I mean where does the truck line begin?
 
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As long as the network does start at the DNB. You can have the DNB in the middle of the network therefore the resistor would not be there.
The resistors should be at the 2 furthest apart points (in metres route length of DNet cable) on the network.

I have always wondered what the defintion of the trunk line is. If you have a 3 metre trunk line with a 6 metre tee off 1 metre from the end then would the trunk line then be 8 metres and the tee-off 1 metre?

Regards Alan
 
If you have a 3 metre trunk line with a 6 metre tee off 1 metre from the end then would the trunk line then be 8 metres and the tee-off 1 metre?
Click to expand...
From what the manual states "If the distance from the terminating resistor to the last tap is less then the distance of the drop measure from the device

I have always wondered what the defintion of the trunk line is.
Click to expand...

Wiki defines a trunk line as "trunking is a concept by which a communications system can provide network access to many clients by sharing a set of lines or frequencies instead of providing them individually"
 
Question, is there a some type of a laptop comm's card needed in order to configure the devices on deviceNet network? I thought I have seen a discussion about this and did a search but came up empty handed. I thought that RsNetWorks would take care of this. Please let me know. Thanks
 
1784-PCD.
It is the right part number, just checked.
I have a series "c",not sure if there's a newer one out there.
Maybe Ken R. can add a bit more info to this.
 
Adam303 - you have a 1756-DNB - do you also have an Ethernet card (1756-ENBT or EN2T) in the chassis?

If you do, you can do your DeviceNet commissioning by connecting to the network via ethernet from your laptop to the ENxT, across the backplane, and out of the front port of the DNB. It's not the fastest connection, as the DNB gives priority to scheduled data transfers, but is a workable alternative to buying additional hardware for the laptop, and if you only have a small number of devices on your network, will probably be good enough.

You could also use a 1770-KFD module. This is a Serial RS-232 to DeviceNet bridge, and will run at very high RS-232 Baud rates (57,600). It works much faster than hopping onto the network via the DNB module.
 
Depending on the age of the card it may even have usb on the front. You can go through that I think
 
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