Some say that in life, it''s the little things that matter. The engineers at Mikron Assembly Technology couldn''t agree more. This Denver-based, Switzerland-headquartered company designs and produces custom assembly systems for high-volume production of a wide variety of small components. The company specializes in assembly machines for parts that must perform precisely as designed, including gas generators for airbags and medical inhalers. The proper function of the parts could mean the difference between life and life-threatening injuries.
Whether serving customers in medical technology, telecommunications, or electrical and household appliances sectors, Mikron''s worldwide mission is to offer customers optimal performance in assembly systems. Assembly is a crucial point in the production chain; it''s where the work of product developers, parts manufacturers, and suppliers is put to the test, and where companies determine whether their production targets are achievable. Any inaccuracies in assembly could lead to product recalls, creating a negative effect on a company''s reputation and financial performance. Therefore, purchasing an assembly system essentially becomes a matter of trust.
Mikron''s standard product line, the Flexcell, is a high performance, flexible, linear assembly cell that offers numerous advantages over competitive systems: fast delivery, modular design, high precision, high speed, cam driven and synchronous motion, and a detailed operator interface with powerful diagnostic tools. A single Flexcell machine is capable of producing four parts per second. This rate equates to about 300,000 parts per day or, well over 100 million parts per year. Users find great benefits from the system''s detailed, automated alarming that alerts production staff of process errors, as well as detailed production performance and manual controls.
Before using the Rockwell Automation-based control system, Mikron offered detailed manual controls only as an option. The ease of use of the RSView ME™ package allows Mikron to provide detailed manual controls for every Rockwell Automation-based Flexcell as standard equipment.
Implementing a PLC-Based Control Option
As part of an initiative to serve the flexibility in design required by North American customers, Mikron wanted to offer Flexcell customers a programmable logic controller (PLC)-based control system option in addition to its PC-based system. Mikron''s North American customers wanted the greater reliability and ease of maintenance that PLC systems can provide in many applications.
To secure the best PLC-based control option, Mikron turned to Rockwell Automation.
"Choosing Rockwell Automation made sense for Mikron," explained Sean Flanagan, controls project manager, Mikron Assembly Technology. "The company''s excellent reputation, combined with customer acceptance of Rockwell Automation products, assured us that this control solution would be readily accepted and implemented by our customers. In the end, we have a product that not only meets the needs of Mikron, but also satisfies Mikron''s customers."
After reviewing the Rockwell Automation line of Allen-Bradley controllers, Mikron chose to build its PLC-based Flexcell system on the Allen-Bradley® SLC 5/05™ small programmable controller. The SLCs are connected over Ethernet to an Allen-Bradley VersaView™ industrial computer with touch screen running the Rockwell Software® RSView™ Machine Edition HMI software. Depending on the size and complexity of the assembly cell, some Flexcell systems use more than 20 SLCs and RAC6182™ terminals.
RSView Machine Edition was designed to monitor and control individual machines or small processes like the Flexcell assembly cell. Because it runs on multiple operating systems including Microsoft® Windows® CE and 2000, and supports both open and embedded HMI solutions, RSView Machine Edition gave Mikron a range of software options to fit different assembly applications.
Flexible Programming Environment
The flexible, easy-to-understand programming environment of RSView Machine Edition helped Mikron reduce HMI development time. As a result, Mikron was able to build in many more standard features on its equipment -- features which were previously optional because of the development time required. The now-standard features offer diagnostic tools for the Flexcell, which reduce machine debug and installation time.
Because they have no moving parts to wear out, RAC6182 industrial computers and monitors were ideal for Flexcell''s needs. With fewer parts to break down, RAC6182 requires less maintenance and is more reliable than the standard PC. The bright, clear, high-resolution screen displays sharp and easy-to-read images, even in low-light environments. The RAC6182 also met Mikron''s high speed, high performance requirements, rating as the fastest among similar products tested by the company.
PLC systems can be easily and quickly modified. PC-based systems traditionally require a higher level of programming, but Windows-based PLC programming software offers a familiar interface to program system functions, and intuitive features to make changes in as little as five minutes. (Typically, these changes take less than a minute for the PLC.) PLC systems can also offer greater flexibility and debug efficiency, since program code can be modified while the machine is running -- meaning users don''t have to power down a portion of the assembly line to make the change. In addition, troubleshooting is much easier, since the programmer can debug a programmable controller many times faster than a computer.
"In addition to faster programming, the ''preferred connectivity'' between RSView Machine Edition and the Allen-Bradley PLCs offered easier connection options than with other HMI products Mikron has used," said Flanagan. "Additionally, we''ve found that communication performance to the SLC and PLC processors is much faster than other HMI systems."
Complete Visualization Package
With the level of detail Flexcell operators require for final assembly, it was crucial that the operator interface clearly present machine status, production information, and detailed diagnostic tools. By using RSView Machine Edition, programmers have a complete visualization package to easily develop and test HMI screens. Programmers can simulate runtime during development, create displays using a graphics editor, use powerful editing and drawing tools, and animate objects and motion.
"Because of the good collection of editing tools, RSView Machine Edition allowed Mikron to provide our customers with a higher quality operator interface with better diagnostic tools," said Flanagan.
Mikron uses the trending feature in RSView Machine Edition to provide customers with a view of the Flexcell performance and process measurements. Additionally, detailed machine performance/downtime reports are generated and displayed on the screen, with the option for sending them to a printer.
"These reports are invaluable for machine debug, acceptance, and production when Flexcell reaches our customer''s plant," said Flanagan.
Using advanced operator interface and control technology, Mikron easily met its objectives for its new Flexcell systems, providing increased reliability, performance, and efficiency to meet its customers'' demanding assembly needs. As a testament to the success of the new design, Mikron recently shipped an entire assembly line to a customer, which included 26 RAC6182 computers connected to 22 SLC 5/05 controllers and two Allen-Bradley ControlLogix™ controllers. Flanagan noted that, when using ControlLogix, the common tag database between the PLC and RSView two is a notable timesaver.
For more than a quarter of a century, Mikron has helped its customers bring reliable, competitively priced products to the marketplace as quickly as possible. Partnering with Rockwell Automation, Mikron can move forward with a new control option that will help build Mikron''s global reputation as a leading assembly systems provider.