The OMAC (open modular architecture controls; http://rbi.ims.ca/3848-527) packaging industry workgroup—which includes an influential group of end users, OEM machinery builders, and suppliers—is moving forward with initiatives that define standards for industrial motion control. The group has endorsed IEC 61131-3 as a standard development environment for programming motion and logic control, and is working to refine a library of motion control function blocks and state machine definitions appropriate for packaging machinery.
In addition to OMAC's emphasis on technical standards, the group has a focus on improving overall business and productivity, and increasing cooperation with other industry groups.
Recent developments include new extensions to the PLCopen motion control library, cooperation with the World Batch Forum organization, and news on programs to improve business results, training programs, and connectivity options.
PLCopen part II
Similar to the OMAC initiatives, by targeting a formal release at this month's Hannover Fair, PLCopen (http://rbi.ims.ca/3848-528) is introducing Part 2 of its Motion Control Library. According to Eelco van der Wal, the group's managing director, the new extensions "are a clear step forward and demonstrate that we are working to improve basic motion control functionality supported by the library." Van der Wal adds that the organization has made it clear exactly what additional functionality should be added in future releases, including "stacked commands" to support both linear and circular interpolation and new functionality for homing.
The basic goal of the PLCopen Motion Control Task Force has been to develop an independent library of function blocks for motion control using IEC 61131-3. The initial release of the library includes motion functionality for single and multiple axes, administrative tasks, and a machine state diagram. The specification provides the user with a standard command set and structure that is independent of the underlying architecture, and has been implemented by a broad group of suppliers.
Part 2 adds a series of motion control function blocks to the library, »which enrich the tool set for the application programmer.
A motion control touch probe provides the ability to record an axis position using a triggered event, and is useful for registration applications. The touch probe can be used with other function blocks to calculate product position and trigger asynchronous events such as printing, gluing, or cutting.
A new digital cam switch function block provides "switches" on a motor shaft. These switches command a group of discrete output bits, analogous to a set of mechanical cam-controlled switches connected to an axis. Both forward and reverse rotations are supported.
A new Torque Control function block exerts torque continuously at a specified torque level using a defined ramp. If the selected torque level is reached, it sets an "InTorque" output. This function block is applicable for commanding both force and torque, and can be used for both continuous and discrete motions. The additions are specifically designed to address capping applications.
Information is available on the PLCopen website (http://rbi.ims.ca/3848-528) for all the new additions to the library, including a new ability to read and write I/O, plus new administrative, status, and reporting functions. Because multiple blocks are often used to create specific application solutions, there are also examples of how to use the blocks to design motion systems.
PLCopen is also working with the OMAC PackSoft Working Group to define functionality specifically for packaging applications. Van der Wal says the group wants to use the standard naming conventions that they have already defined, and create a set of "higher level" function blocks for packaging applications based on the existing blocks in the library.
At its annual forum last January in Orlando, OMAC provided updates on the progress of its individual working groups. The PackAdvantage Team has completed Version 2.0 of its User Application Guide that can be used to calculate the strategic business advantages of a given automated packaging investment. This working group is now gathering examples of early adopters for a presentation on the guide at this year's Pack Expo.
OMAC also announced a cooperative effort with the World Batch Forum to harmonize the group's PackML Guideline with the ISA SP88 standard, where PackML is derived.
At the Orlando forum, Skip Holmes, associate director for Power, Control and Information Systems for Procter and Gamble, gave a presentation entitled "Business Drivers in the CPG and the Strategic View of Packaging." In the presentation, Holmes correlated the investment his group has made in staff involvement with bottom line financial benefits that could reach $15 million annually by increasing reliability, quality, capacity, and speed to market.
Holmes then specifically challenged the user's group to continue to focus on solving business problems, to communicate the benefits broadly and in business terms, to expand the number of participating companies, and to drive the guidelines toward industry standards.