Allen Bradley + Profibus

[collinsd70 30]

Hi All.

 

Just a random question- does anyone know why Allen Bradley don't directly support protocols such as Profibus?

 

I am aware that SST modules can be used- but coming from a Siemens/ Mitsubishi/ Schneider background, all these companies do...

[Ken Roach 194]

It's just a matter of which protocols are championed by the market leaders in their area.     Profibus has deep ties to Siemens, and the risks of integrating Profibus directly into their controllers outweighs the technical and market penetration benefits.

Even though Profibus is in theory an independent technology not controlled by Siemens, they still control the source of good interface chips.  What if they restricted Rockwell from buying them ?   What if they asserted a patent, even without good grounds to do so ?  It's happened before (the Solaia/Schneider affair).

And at the product level, Rockwell's never going to have easy, smooth, simple integration with Profibus like Siemens does.   So offering Profibus integrated into their controllers pretty much would start out with "Siemens does this better than we do".

There's also a matter of competitive differentiation.    Rockwell had ControlNet and DeviceNet and EtherNet/IP, and promotes those in competition with Profibus and ProfiNet.    To adopt Profibus wholeheartedly would give up a major competitive differentiator in which they'd invested many years and many dollars.

I have a Hilscher NT100 bridge on my desk between EtherNet/IP and Profibus DP.    I'm not sure that a built-in Profibus DP scanner in the ControlLogix would be a lot easier to use, if it existed.

[jstolaruk 9]

Profibus would not be a good choice for any new fieldbus venture because its "old".  I've commissioned only one Profibus system in the last 15 years, all others have been Profinet.

[chantecler 15]

 

I faced a situation kind of related to this topic.

I am working on a project replacing the control and servos of a punching press (the project is getting to the installation phase only waiting for some items to arrive). The original idea was to replace only the controller, but the servos communicate with the controller via CANbus network with CANopen protocol. I couldn't find a way to control the servos with my CompactLogix controller cause AB as far as I know does not support CANopen so I ended up replacing the servos too.

CANopen is widely used. I wish AB supported it. I suppose the situation is similar to Profibus's 

Edited 16 Jul 2018 by chantecler

[collinsd70 30]

Agreed...however.

I have worked in many situations now where a robot cell is supplied to customers-  all remote I/O is on Profibus, all Robot Controllers are Profibus Slaves, all Safety is handled via a dedicated Safety PLC via Profibus.

Depending on the customer- they may request Siemens, Mitsubishi, sometimes Schneider (Quantum). However if a Customers Requests AB- then there is no simply transition like with the other vendors above where a PLC must act as Profibus Master. Obviously there are ways around this.

Mitsubishi for example- have there own networks (MelsecNET (H/10) and CC-Link)  but still provide access to other protocols such as Modbus, Modbus TCP, Devicenet, Profibus and Profinet.

From a sales aspect- it just seems odd that AB doesnt have any method of getting into these sorts of markets like the example above.

Edited 17 Jul 2018 by collinsd70

[collinsd70 30]

Im not necessarily referring to the present time- I mean historically...

When I come across these sitautions- im always asking myself this question.

[jstolaruk 9]

The robots coming with the safety fieldbus that didn't fit the application is more a condition of how the robots were ordered. A couple of times I've had to ask the robot supplier to provide Ethernet/IP instead of Profisafe and vice-versa depending on the cell's PLC brand.  The equipment buyer didn't understand or ask someone knowledgeable about what was required and blindly released a purchase order.