By Jeremy Pollard, CET
I couldnt believe my eyes! A real-life application of IEC 61131 technology reported in our March 2008 issue.
I sometimes am accused of being too emotional about stuff, and IEC 61131 is one of those topics Ive been pretty passionate about, as you can see from the numerous columns Ive written on the subject at ControlDesign.com/iec61131. Something has to be real, not because a vendor community tells us it is, or a standards body pounds the table about it.
The article is about Conflex, a manufacturer of automated shrink-wrap machines, and centers around the companys desire to change its automation, and how it found a vendor that has IEC-61131-compliant control and motion software.
I talked to Joe Morrissey from Conflex, who is responsible for sales and marketing. While he admits he doesnt know what IEC 61131 is or what it means, he feels it doesnt matter since his customers dont ask. They are impressed with the service levels and the big HMI screen that has everything on it from soup to nuts.
It makes us more competitive, says Morrissey, referring to the HMI and the machine abilitiesnothing to do with IEC 61131. Our machines have lots of non-tech sales features. Our customers can see videos and schematics on the HMI screen. He indicates that sales volume and profitability have increased.
I then spoke to Mark Lorenz, the Conflex techy involved in the selection process and implementation. In the four newest machines, two were developed using Beckhoff and the other two using Panasonic.
Using IEC 61131 would allow us to program in five languages, although we only use structured text and ladder, he says. He is not familiar with sequential function chart. Seventy-five percent of what we do is in ST, since we can share that code between machines with only some tweaking to be done, adds Lorenz. This suggests that the two vendors are not 100% IEC-compatible in ST. But 90% is pretty good.
Ladder diagram is used for the customer interface and has to be written for each vendor, however, they look very similar because they both use the same German software vendor, says Lorenz. We chose an IEC 61131 platform to make us globally competitive, since our competition [most of which are European companies] use IEC 61131. It was becoming standard.
He went onto say that the standard provided his company with a certain level of security. If others are doing it and we are too, then there is an acceptance level thats immediate.
This next statement is where my hair stands up a bit. Lorenz says that customers are accepting of their IEC-61131 solution because its a standard. It provides a level of comfort for them too, he says.
This is where I feel that some of the automation end user public has had the wool pulled over their eyes. I asked some leading questions regarding compatibility and look and feel between the products he has used. I asked him whether he felt that Rockwell RSLogix 5000 and the software from Beckhoff were similar, knowing that they were both advertised as being IEC-61131-compliant. He says, No.
I asked him the same comparison between Beckhoff and Wago, and his answer was, Some, suggesting there were similarities, but also differences.
Both these vendors use 3S as their base software.
Lorenz suggests that, in our business with multi-vendor usage, IEC 61131 provides benefits for us. Its not like you are going to a whole new environment. Reduced training [for Conflex people] is a bonus.
Lorenz suggested that the startup and commissioning aspect of projects is not affected by using an IEC 61131 platform.
It was really nice to talk with these gentlemen, and I appreciated them taking the time.
It reinforced my beliefs on what IEC 61131 really is, and it is important to the user community for many reasons. Vendors can take advantage of the complacency of some users because of the intrinsic value of the word standard.
I believe that Conflex is not operating under any misconceptions. They use what they use because its what their hardware dictates. They wanted some commonality and they got it. They wanted something globally accepted and they got that too.
Does it matter that its a standard to Conflex? Not much. But its customers might prefer a product that seems standards-based rather than a proprietary offering, regardless of what that means to those customers.
Jeremy Pollard has been writing about technology and software issues for many years. Publisher of The Software User Online, he has been involved in control system programming and training for more than 25 years.