Developing a Flexible Production System for Improved Access and Easy System Configuration

Author(s):
Stig Mathiesen - Grundfos Sensor A/S

Industry:
Oil and Gas/ Refining/ Chemicals

Products:
LabVIEW, Compact FieldPoint

The Challenge:
Creating a system that provides easy access to system configuration and enables adherence to emerging standards and requirements in clean-room gas and liquids control.

The Solution:
Using National Instruments LabVIEW and Compact FieldPoint to design a distributed control system.

Grundfos is one of the world's leading pump manufacturers, with an annual production of more than 10 million pump units. Today, we are the world's largest manufacturer of circulator pumps, covering approximately 50 percent of the world market of heating, ventilation and air-conditioning pumps used in domestic houses, office buildings and hotels. We manufacture also submersible and centrifugal pumps, for example for process industry as well as for water supply and wastewater segments. In addition to pumps, we manufacture electric motors for the pumps and have a considerable production of electric motors for separate merchandising. Furthermore, we develop and sell state-of-the-art electronics for controls for pumps and other systems.

We produce our own chips for the sensors used to control the pumps we manufacture in Bjerringbro, Denmark. The wafer coating process required in the production takes place on-site in ISO class 4 clean room conditions. Air purity is of critical concern to successful wafer manufacturing and ISO standard 14644-1 class 4 denotes a clean room that may contain approximately 0.001% of the count of 0.5 µm particles compared to normal ambient air.

The production is in operation 24 hours a day, 7 days a week, with only one down day allowed per year. The manufacturing site is located in an environmentally sensitive area and an additional complicating parameter is the fact that the mains power in the area suffers from recurring outages. Several outages may occur during the course of one day, each with several seconds duration. The control system measures of the clean room intakes and outputs of temperature, humidity, vacuum, and the quality of water, compressed air and electricity.

We began updating the existing control system in 2005 in order to provide easier access to the inputs and outputs via the local area network, as well as enable the system to be easier to update when new standards emerge. We were highly conscious of the environmental values and pays close attention to the discharges from production so the new system should give us more control of these. Additional goals were to simplify the system configuration and reduce the amount of cabling required.

We used National Instruments Compact FieldPoint distributed I/O modules in various sections of the clean room control system for analog and digital input and output connections. The programming tools used were LabVIEW Professional Development System 8.0 with the Data logging and Supervisory Control Module and Real-time Modules.

The HMI of the entire control system runs from a desktop computer to which the Compact FieldPoint controllers connect via the general company Ethernet network from a number of locations in the production site, the distance to the controlling computer being more than 100 meters.  Operators may also connect to the company network remotely to monitor user interface with a web browser from across the world if necessary.

Each or the Compact FieldPoint units have their own UPS devices to ensure continuous operation, and as an additional precaution the devices been duplicated for backup. As an additional measure of security, the system can send text messages to appropriate technicians in case of system malfunctions or other triggering events, such as when the system has switched to UPS or power generator.  Each event has its own dynamic list of recipients, which for example allow members to opt out from the list temporarily during vacation.

For the programmer of this extensive system this was the first programming project ever and he started the whole application from scratch. He chose not to assign separate programming professionals to work on the application to avoid iteration cycles. In his experience, National Instruments LabVIEW is a good way to get started with programming, because it is easy to use, you get results fast and the program has good tools for debugging. Moreover, he has received invaluable support from the National Instruments Denmark technical staff.

NI LabVIEW has also a number of tools for highly productive programming, for example in this project the LabVIEW Project Manager and shared variables have proven to be useful features for networked applications. The possibility to simulate devices off-line has been helpful as well. The gained experience from programming LabVIEW in the Windows environment made it easy to port some of the algorithms later to the real-time operating systems in the embedded Compact FieldPoint controllers, which lowered the main system load significantly.

The overall system, which has been in production use since 2006, has proven to be fully stabile – no outages have taken place during this time.

Author Information:
For more information on this Case Study, contact:
Stig Mathiesen
Grundfos Sensor A/S

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