DMC was asked to rewrite code from an older version of a packaging machine using a CPG Template for the PackML State Machine. In this machine, product was introduced through an infeed system and moved through two wrapping layers to an outfeed system. The new machine incorporated more servos, the variable package size functionality, and an updated HMI. Due to these new features and the request to use the PackML CPG template, a direct translation from the old packaging machine would not meet all of the requirements of the customer.
One feature of PackML that makes it useful across many systems is its flexibility. The CPG template allows for the customization of the PackML State Machine in a way that makes sense for this particular application. By using tools and resources such as the Siemens PackML Implementation Guide and Planning Spreadsheets, the user can easily create the structure for a unique state machine project. For example, the PackML structure can accommodate up to eleven modes and seventeen states, however, DMC determined that only three modes containing eleven states each were necessary for this implementation. In addition to using the PackML architecture, DMC took advantage of the CPG template’s built-in features such as event handling and OEE data.
In order to ensure that the state machine was operating as expected, DMC used iDevice to communicate between the PLC and the motion controller. DMC chose iDevice to handshake the necessary data between the two devices because only a few bytes of data needed to be shared and it allowed for fast transfer speeds.
The solution was designed to conform to the ISA TR88 standard and simultaneously maintain some similarity to the old program in order to make the operator transition as seamless as possible. By using the PackML State Machine, DMC was able to create a flexible, easily modifiable, and robust solution that can be incorporated into many different systems and is familiar to individuals working with the old version of the machine.