PC control cuts machine design time
Industrial laser-based machines require intricate control systems for precision cutting. Complex controls must be balanced by the operational simplicity necessary for plant-floor production. To ease operation of a new laser cutting machine—while maintaining a tight design schedule—LaseRevolution Inc.
Industrial laser-based machines require intricate control systems for precision cutting. Complex controls must be balanced by the operational simplicity necessary for plant-floor production. To ease operation of a new laser cutting machine—while maintaining a tight design schedule—LaseRevolution Inc. (Grand Rapids, Mich.) uses GE Fanuc Automation (Charlottesville, Va.) Cimplicity PC Control and Cimplicity HMI software for seamless integration between the machine controls and the operator interface.
With a four-month deadline, LaseRevolution set out to design a new machine for perforating 0.0007-in. dia. holes in thin composite sheets of insulation commonly used in home construction. The tiny holes are large enough to allow the house to "breathe" but not big enough to allow wind to whistle through or water droplets to penetrate. According to D.J. Regan, vp of engineering for LaseRevolution, "Selection of a PC-based control system allowed the company to cut this machine's design time by more than 50 percent.
"We designed the new machine much faster, easier, and for thousands of dollars less by using Cimplicity PC Control," Mr. Regan says. "With this software, we avoided the inherent limitations of ladder logic. The resulting system is easy to use, and our customers don't have to be control experts."
According to Mr. Regan, Cimplicity PC Control offers several advantages compared to conventional systems—from programming to operation and troubleshooting. Particularly useful for LaseRevolution was Cimplicity PC Control's use of natural, structured text programming that is both self-documenting and easy to debug.
By integrating Cimplicity PC Control with GE Fanuc's Cimplicity HMI, LaseRevolution eased machine control with a Microsoft Windows-based graphical user interface. The HMI software provides operators with data on the status of the laser's operation and position through four selectable screens on a touchscreen monitor. The touchscreen allows immediate feedback from machine to operator and permits real-time modification of parameters. For example, slider controls let the operator set laser power and frequency directly in real time, without relying on A/D (analog to digital) or D/A controls.
The HMI software receives data from PC Control, which monitors and controls GE Fanuc Series 90-30 I/O devices including two analog outputs, 30 digital inputs, and 30 digital outputs. Sensors measure laser duty cycle, pulse frequency, and other operational criteria.
"With Cimplicity PC Control, we don't have to rely on intelligent sensors, Mr. Regan says. The 'brains' of the system remain in the PC, where the real processing power is. Additionally, improving system speed now is only a matter of upgrading the PC, the microprocessor, or adding a clock doubler."
"One sensor measures speed as a differential on a rotary contactor and updates every 5 milliseconds (msec) to determine speed," he says. The speed being measured drives the process to determine perforation frequency, and so must be measured in real, not delayed time. The system currently updates once each 10 msec because code was written specifically to ease troubleshooting. Improvements in processor speed and streamlined programming will allow the system to cut update cycle time in half.
Because the GE Fanuc system operates on a Windows-based PC, LaseRevolution can monitor and troubleshoot the production system without visiting the facility where the laser is installed. Because the machine can be debugged remotely, response time is improved and downtime is minimized. In addition, by accessing the machine directly via modem or through the customer's local area network, troubleshooting does not rely on an operator relaying conditions and error messages.
The control system is said to be easily integrated into larger system networks. Additionally, the software permits advanced datalogging and alarm capabilities, which LaseRevolution implements on request.
"The lasers are pretty smart by themselves, Mr. Regan says. They'll shut themselves down if there's a problem, so not a lot of code is needed for alarms. However, if enhanced alarms or logging are required, they're easy to add. Cimplicity HMI also allows additional screens to be added or moved as required."
For more information visit www.controleng.com/info .