It's an exciting, tumultuous time in the machine control field, says Ken Crater.
Design News: What advantages would a standard, portable machine control language offer to industry?
Crater: There's an advantage to be achieved there, but it's not as strong an advantage as is assumed in many of the reports we've been reading lately. For the engineer who actually has to apply the hardware, portability tends to be far less of a concern than functionality. He or she has agility as a major concern these days--the ability to be able to move very quickly, and to get a machine up and running in very little time. Given that circumstance, broad, sometimes academic goals such as portability don't enter into people's thinking quite so much.
Q: Your company offers controls based on state language. What is state language?
A: State language expresses a program as a series of steps. The steps are exactly equivalent to those that an automated machine goes through in its function. There's a one-to-one correspondence between what the machine will do on a step-by-step basis and the way the program is structured. There is almost no interpretation involved to get from concept to programming. In effect, a step is a very comprehensive description of the machine's performance and operation.
Q: How does a state language handle simultaneous, asynchronous operations?
A: We have addressed this need with a very powerful multi-tasking framework--actually an operating-system approach. Because we have developed purpose-built hardware and an operating system that runs on it, we were able to create a real-time operating system that supported multi-tasking with a state language interpreter. So we can run multiple state language tasks simultaneously--just as though you have 3, 4, 5, 6, or 20 controllers running your machine.
Q: What roles do you see for objects in machine controls?
A: There has been a lot of fast and loose talk about objects in the controls industry. The marketing people of just about any company in the industry will tell you that, oh yes, they have objects--but then the details become a little hazy. An object is an entity you create in software that has one or more methods that it can perform--a method meaning an action or function. There is no true object-oriented programming language on the market today for machine control. Object-oriented programming is a tool for organizing a complex program so that mere human beings can understand it. The older procedural programs are very difficult for human beings to wrap their brains around.
Q: How might agents be used in machine control?
A: There's an awful lot of new technology to be developed and digested in the industrial control arena before agents can be implemented. In a nutshell, an agent is a software entity that might be sent across a network, land in some remote hardware environment, run there, gather information, perhaps move from there to some other environment, gather information there, process that information, and return some conclusions to you. Or, taking a major leap further, you could give it some instructions to go out and build a red car, and it would jump around from machine to machine until its mission was accomplished.
Q: What trends should engineers take note of in your field?
A: The biggest factor driving our industry right now is the information explosion. It will dramatically change the future of products and support software available in our industry. We've only begun to see the changes that this one factor will bring about in our industry. Every machine on the shop floor in the future is going to have to be highly communicative. And rising to this challenge is going to strain the resources of many of the staid old companies in this industry.
Q: How does the market react to such new technologies?
A: The PLC was quite an innovation in its time. People didn't trust the electronics solution, so there was a very great hurdle to overcome. There was just glacial movement in the evolution of the PLC until about the mid-eighties or so. What you're seeing now is a change of dramatic proportions. Customers are demanding new technologies from manufacturers at a rate faster than they can deliver. Every manufacturer on the face of the Earth seems to be facing competition like they have never seen before. And that has forced them into a posture of accepting, demanding, and expecting new technology.