Festo introduced valve terminals to the automation sector more than 30 years ago, moving the technology on from purely mechanical/pneumatic sub-bases by adding electrical connections for the solenoids and feedback signals. The machine building sector welcomed the time and cost saving innovation with open arms and valve terminals have been incorporated into most automated machines since then.
Festo established one of its largest ever, cross-function design teams to look at what machine builders are looking for in the next 5-10 years. They developed a new product range to be called VTUX standing for Valve Terminal Universal”, addressing within the single platform, new pneumatics and electrical connectivity.
The team focused on creating a platform that spanned from high-volume, low-cost, basic functionality to highly featured, technology rich options that addressed future technologies and specialist requirements in sectors previously seen as niches. The “X” in the type description signified the ‘built-in flexibility’ to incorporate many new and innovative features in the coming months and years.
Central to the platform concept was that customers only pay for the performance and features they actually need. Therefore, for the simple operation of solenoids through multi-pin cable connectors basic valves can be ordered ready assembled onto a basic manifold base, with simple one direction internal ‘wiring’. If an existing bus system is preferred, then the basic low-cost terminal can be upgraded to a field bus connection. However, if more advanced features are needed then the specification can be incrementally uplifted to suit the application requirements.
Integrating a ‘serial comms’ backplane into the bases means bi-directional communications are opened-up. The maximum number of solenoids on a terminal are no longer constrained by the number of wire connections running between the bases. Sophisticated sensors enable closed loop control possibilities, for example energy-saving vacuum modules that only call for air flow when the vacuum level decays. Internal sensors also enable predictive maintenance monitoring including the Festo AX AI assisted software.
The Festo VTUX developers intensively modelled the features required such as higher valve flow rates, reduced space footprint and increased operating life alongside the project’s sustainability goals such as improving the electrical (solenoid coil) energy efficiency. Sustainability considerations extended beyond just the terminals’ operation by looking at reducing the energy and materials needed during manufacture and assembly production, and reducing the product’s overall climate impact.
This approach enabled a dramatic rationalisation of internal components resulting in immediate customer cost savings. For example, the latest generation of 10mm wide solenoid valves used on the VTUX terminal have such a high flow rate the valve itself isn’t the throttling bottleneck, instead the maximum diameter of tubing and fittings that will fit within a 10mm wide base define the limits. This meant that an easy way to rationalise the number of constituent parts was to utilise one valve body size across the standard 10 mm, and a wider, 12mm sub-base. This means customers configure wider bases only where they are needed for higher flow rates e.g. for larger diameter actuators or faster cycle rates. Conversely, they can save on the overall width of the terminal and reduce unnecessary air consumption by using the narrower bases and smaller diameter tubing where this is sufficient for their application.
Alongside the introduction of the new VTUX valve terminals Festo advocates the use of its simulation software for the optimal sizing of actuators for overall compressed air usage reduction. Downsizing actuator sizes, tubing diameter and length and optimising the pressure for forward and return strokes can reduce air consumption of a machine by 40%.
Electrically, optimisation on valve terminals is a matter for machine builders of familiarity, cost and flexibility. The requirement for controls familiarity comes from the need for the software writers and commissioning engineers to be able to quickly and error free integrate the new terminals into the overall machine. For end-user OEE (Overall Equipment Efficiency) this familiarity extends to service and maintenance functions for fast error detection and advanced diagnostics.
How machine builders connect between their control system (the brains) and their machine level, sensors and actuators is critical and where they can make their biggest savings or create some of their biggest issues and losses. Therefore, as the VTUX valve terminals were under development, in close co-ordination the electrical and controls team were developing the new electrical connectivity product range called Festo AP, short for Automation Platform.
This form of connectivity provides a lower cost, but fast and powerful connection technology for the last few metres on a machine. It seamlessly collaborates with IO-link or Ethernet technologies providing cross-protocol connectivity and transparency. Simple, intuitive function blocks and integrated documentation provide essential time-savers.
Festo AP addresses key the needs of both serial and special purpose machine builders enabling them to meet their customers’ specification and if needed, change PLC manufacturers whilst retaining up to 90% of the remote IO [RIO] field and cabinet level components. This dramatic reduction in work to change between PLCs makes it easier, and lower cost, to support a range of machines and create a range of machines based on common technology and components.
The AP system delivers interconnecting, modular, decentralised IOs on a scalable, flexible, and powerful communication backplane. It provides robust, modular RIO components that can be field, or cabinet mounted, alone or in combination. The system uses a single header field bus module which is networked to a broad range of input, output, and pneumatic solenoid valve terminals.
AP system topology can be flexibly arranged to suit the physical machine layout and its control architecture. This lowers the cost compared with using multiple field bus nodes and yet is still easy to address and completely transparent within the PLC software.
The new VTUX valve terminal and the AP connectivity platform provides machine builders with the opportunity to save considerable costs and increase their machines’ performance whether they are used individually, or most powerfully, when combined. New components and features are being added to the range every month and visitors to Festo’s Northampton site or forthcoming exhibition stands will see the latest releases and gain a glimpse of near-future rollouts.