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Motion Control part 4 now released

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PLCopen shows Proof of Concept

At the SPS/IPC/Drives in 2004, PLCopen showed a flow wrap packaging machine completely based on the IEC 61131-3 structured approach and the PLCopen Motion Control Function Blocks.
With a capacity to wrap 2,000 products per minute, this clearly shows a proof of concept.

With cost savings in the software development, adding new features, increased software quality, shorter installation times, and better maintenance, it helps the supplier to maintain its market position world wide, while supporting multiple platforms. In addition, it saves cost at the user side. Not only with reduced initial costs, but also in the life cycle costs.

With this proof of concept, we will see a broader usage of the combination of IEC 61131-3 and PLCopen Motion Control, with better market acceptance, reducing costs. Or otherwise said: for efficiency in automation – the new PLCopen tagline.

Tevopharm introduces packaging machine with PLCopen Motion Control

Tevopharm BV, The Netherlands, developed a new packaging machine, which is completely based on IEC 61131-3 and the PLCopen Motion Control Specification for logic and motion control. This certainly can be seen as a proof of concept. This article describes the origin, the implementation, and the benefits.

1.1 Introduction into Tevopharm

Tevopharm B.V. was founded in 1959 in Schiedam, The Netherlands. The Dutch company has about 175 employees generating annual sales of approximately 30 million Euros. With over 5,000 flow wrapper machines sold, it is worldwide active, with approximate turnover of 35% in Europe, 35% in North America, and 30% in Asia and the rest of the world.

1.2 Introduction of the machine

The first machine from Tevopharm that is build around the PLCopen Motion Control Function Block Library is the PACK-300CA Flow Wrapper. This machine is capable of packing up to 2,000 products per minute.

The Tevophram machine

Schema of the Tevopharm Packaging Machine

The PACK-300CA contains three servo drives steering the following functionality:

  1. The product infeed chain (M1)
  2. The film feeding and alignment (M2)
  3. The cross sealing part (M3)
To control these servomotors a ‘virtual line shaft’ is used in the controller. All servomotors are coupled to this virtual line shaft via the control software. The infeed servo has a one-to-one relationship to the virtual line shaft. The second motor follows the virtual line shaft, while keeping the print on the film aligned with the rest of the process. The third motor is coupled to the virtual line shaft via a specially designed profile. This profile assures that the sealing and cutting of the film is done at the right place and with the right speed.

1.3. Rationale of using IEC 61131-3 and the PLCopen MC

Due to their worldwide operation, Tevopharm has to support multiple platforms as requested by their customers. Support for multiple platforms results in a high cost content in the software, due to multiple training costs, multiple application developments, multiple debug sessions, and increased installation and maintenance costs. To reduce these costs and to create optimum customer value, a hardware-independent development of the application software is needed, with a high level of standardization, especially in the software section.

Around five years ago, Tevopharm initiated a project for the PLC software development to move to configurable elements as provided by the worldwide programming standard IEC 61131-3. This means that the functionality of the each application program for the machine was constructed from a pre-defined and tested set of building blocks.

The next logical step in this was to include the motion control section. PLCopen had just released the first part of their Motion Control specification, providing an integration of logic and motion into one environment. With this, Tevopharm would be able to use the same environment with the same language for both the logic control and the motion control.

1.4. Resulting benefits in training, service, support, and maintenance

This approach results in a reduction of the training costs – both at the supplier and the user. Besides the reduction in training needed, the needed level of education is reduced, resulting in maintenance and service personnel whom can be universally deployed. Overall, the usage of world wide standards offer for both the OEM suppliers as well as the users, clear benefits:

  1. A world wide software standard which everybody can easily learn and understand;
  2. The development and installation of new machines is faster, more predictable, easier. This results in shorter time the with less risks, meaning a quicker productive line: while adding last improvements during full scale production could sometimes take up to few weeks, can now be done days, benefiting from improved software quality;
  3. The software for a particular machine is no longer developed hardware type or brand. If platform becomes obsolete, the supplier even ceases to exist, investment in largely protected as it can easily be ported onto different This secures customer investment.

1.5. What was learned?

A user (customer) already familiar with the IEC61131-programming standard and the PLCopen Motion Control functionality can easily read a program. The same ‘look and feel’ principle to be achieved works in reality!

During the realization of the machine software it was understood that the basic PLCopen Motion Control Function Blocks are sufficient to control the machine. Hardware supplier specific options can therefore be neglected, enhancing the ‘look and feel’ principle even further.

1.6. Future aspects

Where servo technology has started as a technology push market, the trend is towards commodities-usage. Open and universally readable software will lead to a situation in which basically trained personnel will be able to maintain and service the equipment. No longer will highly trained engineers be needed to perform this job.

Furthermore will the increased importance of standards in both hardware and software lead to a lower price level of high quality components, even to be provided by the major suppliers of this world.

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