Profi Bus via Controllogix?

[Beryl]

I have been asked to find the possibilities (pros and cons) of tying a Profibus network to my Controllogix. I know AB has a serial converter box that will allow it but you need ProSoft and I would imagine that the performance would be brought down due to the serial interface with the DP/PA network. Anyone used one of these setups before? What I wanted to see was a “scanner” card that plugged into the rack just like DNet or ControlNet. I know this is unconventional but we already have a ton of Profibus devices but outdated PLC’s and we are not real hot on moving over to the S7 platform and are considering other avenues. Any knowledge or input would be appreciated.

Thanks,

 

[rdrast]

SST makes a good Profi module for CLX...

http://www.mysst.com/bcm/pfbclx.asp


If you are comfortable with Rockwell PLC's and CLX, I would strongly urge you NOT to try to switch over to S7... I use both, but S7 jobs always make me cringe.

 

[Beryl]

I would have to agree with the S7 statment. I have been using AB and Omron for quite some time and just started using S7 during the past year and have found it quite combersome. Thanks for the link.

 

[Ken Roach]

I've used the Profibus module for the 1756 chassis a couple of times. It's a key to retrofitting old TI-545 systems without pulling out the 505 style I/O racks.

The configuration software isn't bad. You plug in via an RS232 port on the PFB-CLX module and run SST's configuration software. It was usable with every Profibus slave I tried, but I haven't used it extensively with modern Siemens modular I/O.

A glitch that bothered me is that the configuration software would only go online right after reboot of the module. That wasn't a big deal, as I had to shut down the I/O network to do changes anyhow, but I never did figure out how to configure the interscan delays or update rates to eliminate that problem.

Because Profibus can use a byte order that's different from ControlLogix, I often do have to perform byte-swaps on blocks of data coming in from various Profibus slaves.

I ran the Profibus network at 12 MB with success. I used a straight Profibus connector for one job, and had to do a little Swiss-Army surgery on another PFB-CLX to fit a right-angle Profibus connector.