Manufacturing control technology has been swiftly moving out of cabinets and finding a place near and oftentimes "on" the machines controlled.
The On-Machine™ approach has shown surprising cost advantages in pre-testing. "There are things that we never envisioned as potential cost savings that we''ve now been able to achieve," said David Ansell, director of controls engineering and field operations at Acco Systems. "For example, one of our lift table models is extremely difficult and labor-intensive to position and set up in the field. Because we can test them in our shop now, we can set these positions here. And since the switches are located in the main body of the lift table, we don''t have to remove covers and things like that in the field. We can do all that in our shop now."
Installation Time Is Reduced
A traditional control system installation is seldom simple because there are a lot of possibilities for mistakes with so many hard-wired connections. Using wiring modules and quick disconnects, as well as moving industrial controls and hardware closer to the application or on-the-machine have proven to save considerable time and money --enough to more than offset the slightly higher component cost.
David Girard, senior controls project engineer at Cinetic Automation, pointed to one of their customer installations as an example. The system has several hundred pneumatic valve manifolds; each manifold has an average of four double solenoid valves per manifold. With conventional installation and wiring methods, each solenoid requires two wires for each solenoid -- the output and the common -- for a total of four wires for each double solenoid valve that must be wired in at the valve and then again at a local terminal box and then a third time back at the main enclosure. That''s 64 wire connections on average per manifold, which can equate to thousands of wire connections for an entire assembly system (this does not include the cost of the wire, terminals, cords, terminal boxes, wire duct etc.).
"At teardown, you have to disconnect all the wires out of the terminal boxes from the main panel, ship it, and hook the wires back up again at the end customer''s facility," says Girard. "The most conscientious electricians are still going to spend an extensive amount of time wiring in all these connections. The boring and time-consuming nature of this process alone opens the door to costly wiring mistakes and possible damage to the equipment."
With the On-Machine approach, Cinetic Automation has zero wire terminations required for the pneumatic valve manifolds because the valve manifolds are internally connected from the manufacturer and there is only a fieldbus connection for communication to the network. The fieldbus communication connection is accomplished through a molded M12 connector that the installer plugs in and tightens down. There is no longer a need for terminals, terminal boxes, cords, home run wire bundles, wire duct, etc.
Not only are there fewer problems associated with installation, the process takes less time. The engineers at Cinetic Automation have seen their teardown reinstallation time decrease by more than 50%. "Where it used to take us months to bring up equipment online, it now takes only weeks," Girard said.