DeviceNet Adapter Questions

I see few posts about DeviceNet. Is it because it works without problems or nobody is using it? I need a DeviceNet PCMCIA card or a USB to DeviceNet converter or a Ethernet to DeviceNet converter. Does anyone have any recommendations? Must I have a Rockwell DeviceNet master to program Rockwell PLCs over DeviceNet or will others do?

If you goto http://www.odva.org you can find a listing of devicenet products, AB makes a pcmcia card as do others. I have used RSNetworx with a system that was all AB and it was fairly simple. I have been involved in 3 systems using devicenet, 2 AB and 1 Horner. I do not know of any problems with any of the systems and it DEFINITELY makes the wiring easier.

Peter, Since you mention ethernet, I assume you are using control logix. You wont need any card or adaptor. Just plug into the ethernet network, fire up the RSNetworx for DNet software and you are away. Regards Alan Case

Most people that I have ran into that use DeviceNet are not big fans. Those that have used both Profibus and DeviceNet say they would choose Profibus most any day over DeviceNet for ease of use in setting up and maintaining the network.

I personally have never set up a DeviceNet network, this is just what people have said to me about it. I did troubleshoot a Profibus netowrk yesterday without knowing much of anything about the software or the network and found the problem within a reasonable amount of time.

rsdoran said:

I have been involved in 3 systems using devicenet, 2 AB and 1 Horner.

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How was the Horner system's support for devicenet and its performance?
I will certainly get the AB stuff as I think 80% of our customers will be using AB, Omron and Eaton will probably make up the rest.

What devicenet master did you used to talk to the AB stuff?

This must be DeviceNet

icky812 said:

Most people that I have ran into that use DeviceNet are not big fans. Those that have used both Profibus and DeviceNet say they would choose Profibus most any day over DeviceNet for ease of use in setting up and maintaining the network.

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We already support Profibus DP with our current product. This inquiry is for new products that have a DNET controller built into the microcontroller so we will support DNET for these new products.

I think you are right about Profibus DP being much faster. However, I have found that DNET is smarter because it has an application layer whereas Profibus DP is just a datalink layer. The key thing is that the AB PLCs make it easy to send and receive parameters with the MSG block and real time I/O shows up in the I/O registers. Profibus DP doesn't do the messaging and many of our customer are not capable of writing a messaging/application layer for the Profibus DP. In the end the winner will be the one who makes it easier for the user. In this case ABs MSG blocks with DNET may be easier for simple applications.

I use Device Net quite regularly.

Oh I am glad my preference is Omron. Device Net configurator software, plug your normal programming cable into the processor and away you go. NO special cards or anything else.

Mind you they used to use a PCMCIA card but that was a long time ago.

You do not even need to use configurator software for small systems. Device Net I/O modules are automatically allocated to memory areas. I prefer to configure them to different memory areas.

My only grumble with Omron is explicite messaging. That is a bit of pain to set up the first time. Once you have done it it is easy the next time.

I like Device Net. It is extremely easy to set up with my preferred brand. Not so easy with others.

I do not really like anything Siemens. Have had too many problems in the past, both hardware and software.

The Horner system is similar to what Bob said about Omron, the programming is all done with CScape. With the Horner OCS you can order them as CAN or DNET , in our case we needed the CAN so used an adapter, HE800DNT450, which is a DeviceNet master. The only problem I had was with Toshiba giving us the wrong interface adapter for their G7 drives, I spent several days before learning I had the wrong adapter. The only other problem I had was my own ignorance, I had the PLC in stop mode so nothing would work...that was 2 days.

The AB systems were identical and used the 1747-SDN with an SLC 5/03 to communicate with 160 SSC drives for speed control. After that the system gets a little strange but what we did next was "cost conscious". We didnt use DNET field devices, this was done with an SST ASi interface and the yellow cable with the sensors etc from IFM. ASi is a electromechanical connection system that allows input/outut over a 2-wire system, up to a 100 meters, which I believe now has extender(s) to go further. It can also be used with Ethernet. I definitely like it and the devices we used from IFM.
http://www.as-interface.com/aboutasi.asp

I have never done a Profibus sytem but have worked with some and I think DNET may be easier in some ways.

I'm strongly pro-DeviceNet, to the point that around our sales district I'm referred to (to my face !) as the "DeviceNet Evangelist".

As a general rule, you need an interface and software from Manufacturer A to set up a Master device from Manufacturer A. Sometimes you don't need an interface to the network because a PLC is providing that interface (Omron and A-B's Logix systems).

Most slave devices do not require vendor-specific configuration software because they can be set up by an EDS-based configurator. Popular ones include RSNetworx for DeviceNet, NetTool-DN, Omron DeviceNet Configurator, and C-H Studio.

I can't live without my 1784-PCD card because it provides fast direct DeviceNet access for RSLinx and RSNetworx, as well as supporting my traffic analyzer tools. My lab has ISA and PCI cards from SST and Applicom, but neither of those support RSLinx.

Know where you are coming from Ken. It is a very good I/O network.

I find with Omron I do not need any extra cards for my PC. If I use Controller Link, or one of the other Omron networks, a simple serial cable into the processor gives me everything. The connection uses "toolbus" at 115k and I can access every PLC on the network from any PLC in the building.

The simple cable interface also gives me access to the Device Net Scanner with the configurator software, a serial unit on the PLC with CX-Protocol for all my serial interfaces, and programming/monitoring of course.

All manufacturers have different ways of doing things for sure. The simpler the better.