Device Net Master Card

[Paulyo]

I found on an Australian website a F2-DEVMSTR for the DL205 processor.  Is this a typo or is this product for sale in other markets?   If you do a Google search for F2-DEVMSTR it came up with a couple of entries.

[Controls Guy]

I would also love to have a Profibus scanner, as well as possibly one for Allen Bradley Remote I/O.

[franji1]

You'll probably want to post this question on the ADC forum too.  Host Engineering does not make any DeviceNet modules, Facts Engineering does.

We do make the ProfiBus slave module, but no plans on ever developing a Master (too much development cost, not much sales, and it would help sell other vendors I/O, not ADC's - one strike is bad enough, 3 is really really bad).

[Controls Guy]

That's one way of looking at it, but some people make them, so somebody's buying them, and they're also buying PLC's that master these buses as well.  And don't forget, AD already makes Profibus I/O (Terminator or 205 with one of your adapters), so it's not necessarily corrosive to the use of AD I/O to have more ways to do it.  I, for one, on a job using AD I/O and CPU's would use a widely supported bus over an AD one if I had the choice and the cost wasn't too great.

AND, don't forget that it can unlock the door to projects they're never even considered on now.  There have been retrofit projects where I would have used an AD processor if I could have just removed the PLC and controlled the existing I/O.

In some cases, almost ANY widely accepted bus would be adequate, because I'm talking about a local rack where the PLC is going to get removed and the local bus adapter will have to be purchased, so support of any bus for which I could purchase an adapter for the existing rack I/O would work.  But, when given the choice, I like Profibus.

[franji1]

and the cost wasn't too great

Hmmm - ever wonder who makes the Profibus chips and the DeviceNet chips?  Do you think they give them away like 8051s .  Also, the certifications for MASTER cost big bucks.  And guess who certifies them?  And they do it for free !

First, they wouldn't be cheap.  They can't be cheap.  Trust me, people are not jumping at the inexpensive Profibus slave modules (as compared to EBCs, which are in the same ball park around $280).  If people would be willing to pay $1000+ and buy hundreds of them per year, we would definitely look at it.

And, honestly, I don't think people would pay big bucks to network Automation Direct controllers to each other when they can do it much cheaper using ERM/EBCs/ECOMs (wiring alone!).  Any Profibus or DeviceNet customers out there are looking for cheaper ways to interface their expensive I/O that already exists.

Everybody would love ADC to sell a Profibus Master for $250 (well, not everybody, but at least 10 people would).  I would love to buy a Corvette for $15,000!  GM sales would go throught the roof (every male between the age of 16 and 106 would buy one!)

[Controls Guy]

Ah, they charge more for certifying the Master than the Slave?  Slick.  I still maintain that ADC needs to get on the mastering side of some competitive buses other than Modbus and Modbus TCP.  It's possible that the scanners would be loss leaders to sell PLC's.  Like I said, there's business ADC doesn't even know they're not getting because of this issue.

About 10 years ago I was involved in building machines where I used SLC's for control and DL205's as Modbus slaves for remote I/O (and yes I ponied up the $1200 or whatever for the Modbus card for the SLC).  I used hundreds of them and would have used the Profibus slave adapter if it had been available at the time.  I actually benchmarked the configuration later when you guys started selling it, and it knocked the doors off anything else I'd used.

[franji1]

Ah, they charge more for certifying the Master than the Slave? 

  Yes, and rightly so.  As a Slave, you only need to support the functionality that you support.  As a Master, you have to work with ANY AND ALL CERFIFIED SLAVES.  Also, the protocol is MUCH more complex as a Master than as a Slave.

Heck, how long did it take Koyo to get the MRX/MWX stuff working for Modbus/RTU so you could address any Modbus slave?  We still have hacks in there for the RX/WX Modbus/TCP.  And Modbus is a VERY SIMPLE protocol compared to DeviceNet or Profibus!

It would cost millions of dollars and thousands of lives.  Do you want that on your hands!?!    I'd rather be working on cool new features in DirectSOFT and PLCs (like IBoxes) that just about EVERBODY can utilize, than on stuff that nobody would buy (well, a few people would buy). 

[Paulyo]

The List Price in Australian Dollars is $660 or 635 USD.

[Controls Guy]

Man, they got "affinity cards" for everything now! Next will be the Profibus Visa.