It’s not widely known that I am a pretty good cook. My cooking skills go all the way back to my first job as a short order cook for Walgreens restaurants. Yes, Walgreens used to have restaurants. In fact, the first Walgreens had the old fashioned soda counter. They expanded that over the years into full fledged restuarants.
I was hired on as a dishwasher and was quickly promoted to “the grill”. It wasn’t hard. One of the grill cooks had two loves Lynyrd Skynyrd and dope; generally both at the same time. The other was a complete moron who had a hard time finding his way from the fryer to the grill. Compared to those two yahoos I was Henry Ford, Albert Einstein and Wolfgang Puck rolled up into one. [The best thing about the job was the string of new waitresses that were hired every week but that’s a story for another day]
I got to thinking about those days when talking with a customer about his recipe problems. Recipes were something we routinely tried to evade at Walgreens.
But that’s not the kind of recipe this guy wanted to talk about. His company cuts and shapes metal. Lots of it. He’s got 500 Analog values and some other miscellaneous pieces to download every second into his ControlLogix to control the manufacturing of the next part.
He gets this stuff from an enterprise database located in corporate on a server that he can’t touch. Right now he’s built an application on RsLinx but like so many guys I talk to, he just hates RsLinx. I gave him a couple of options.
The least expensive option that gets the job done with some hassle is our 490NBA. That guy moves TCP data to a ControlLogix PLC He can build an application to read his database, stick the data in a TCP packet and send that TCP packet to the 490NBA that will write an array tag in the PLC. His biggest problem is that a Logix PLC can’t handle all the data in one swoop. He has to do multiple connections to the 490NBA or implement his own fragmentation. It’s not pretty but it’s a cheap and reliable solution.
Another option is our new PLC Database interface unit. That guy can associate tags in a PLC with Attributes in a Database and do an exchange. The same kind of rules apply as before but that part is a little easier to manage. We use ASP (Active Server Pages) to interface the database and that has both an upside and a downside. On the upside ASP allows us to interface anybodys database. On the downside, the customer has to write the ASP from our sample. That does have some advantages as they can do formatting and manipulation of the data in the ASP. That unit is shipping beta units right now (Feb 2011) so call if you’d like to try it.
The most expensive, highest integrated option is our ControlLogix Interface Software. We call it the Tag Client. That royalty free, ANSI C source code simply allows you to read or write any tag in the PLC anytime you want. It gives you the most flexibility and is really very easy to implement. You can get it going in under 2 hours most of the time.
Not sure what this guy is going to do to solve his recipe problems. It will be interesting to see what solution he chooses.