Dry Fountain: PLC electronic control system

When a fountain is of a dynamic kind, as it usually happens with dry fountains, it needs a control system to manage water features, lighting and sound (in Waterboy), as well as the synchronization between all these features. Read More

The chosen system is determined not only by the Waterboy model used in the dry fountain, but also by other features:

• The fountain’s type of dynamics (performed by a previously-recorded operation sequence repeated by the device on a cyclical basis).
• The synchronization between water features and lighting.
• The fact that the fountain is musical or not.
• The economic valuation, according to the number of elements that will have to be managed by the system.

In order to correctly manage these features in dry fountains, there are two types of technology resulting in two respective control systems. Now we will take a closer look to them.

1. PLC-based systems

The acronym PLC stands for Programmable Logic Controller. The PLC is an electronic device whose internal memory stores a program or sequence designed to automate a process. Where ornamental fountains are concerned, the stored issue is the cyclical sequence that manages all the hydraulic elements of the fountain – pumps, electro-valves, frequency converters, etc.

These systems are very stable and safe elements: this is the reason why they are widely used in industry. The popularization of these elements has made them quite cost-effective, and with the trace of time they are providing an increasingly better performance. SAFE RAIN uses these control devices in fountains with a number not too high of elements to be managed, or in installations where the synchronization with outer elements is not very demanding.

1.a) SAFE RAIN PLC-based control panels for dry fountains.

The control panels made by SAFE RAIN with this technology leave the factory fully adapted to each client’s particular fountain. In order to achieve this, the technicians of SAFE RAIN and the client will have met before to define how the latter wishes the fountain to work. When the client receives the panel, the only thing to be done is to connect the elements to the panel’s terminal block and to switch it on.

Hydraulic control:

• So the system can manage the fountain’s hydraulic features, the desired working sequence must be previously recorded (as stated before, this sequence will be cyclically executed). Any modification of this sequence must be done by a professional worker specialized in PLC programming.
• In these systems, each electro-valve or pump is managed by a PLC output. Accordingly, the PLC would not be recommended for big-sized or complex fountains with a high number of inputs and outputs. For those cases there are other technologies that optimize the programming in a more efficient way.

Light control:

The PLC control system manages all the lighting features: on/off, color and intensity (when possible). There are three possibilities:

• Controllable RGB lighting – In order to manage it, a clock for controlling the switching on and off must be included in the system, together with a RGB controller.
• Non-controllable RGB lighting (self-changing) – It must always include a programmable clock.
• White Lighting – A clock for activating the pump or the electro-valve must be included in the same output as the PLC.

It must be remarked that the PLC is not able to synchronize water features and lighting, or to make two subsequent light and water cycles coincide in time. To achieve synchronization, first it is necessary to adjust carefully each field’s programmed sequences.

The less amiable feature of these devices is programming. That is, the necessity of defining an output sequence for all the elements of the ornamental fountain. PLC manufacturers provide communication software with the devices, but their programming requires the services of a specialized technician. Similarly, the modification of this sequence (if it does not meet the fountain’s exact requirements) must be done by qualified staff. In order to prevent this inconvenience, a certain technology has been developed so a non-specialized user can program all the fountain’s elements, including the frequency converters. This technology is called HMI.

1.b) PLC + HMI (Human Machine interface)

This name is given to a last-generation development, created by SAFE RAIN and that significantly improves the performance of the PLC. This system includes a HMI or Human Machine Interface (a user-friendly touch screen) that makes it possible to modify the previously recorded sequence in a simple and rapid way. This means that the modification becomes accessible for non-specialized users who can do it through an intuitive touch screen. It is a very efficient system that goes far beyond the performance of the PLC by itself.

Main features and advantages

• This system offers new operation-and-modification possibilities, added to the PLC’s existing ones. These possibilities distance themselves from the complex and laborious binary language to become a fully graphic, understandable and user-friendly option.
• The scheduling (switching on off the installation) is included in the software.
• It can associate operation sequences with concrete dates. In example, we could program a fountain so on the 25th of December it would initiate the ‘Christmas’ sequence.
• The PLC + HMI system offers the possibility of testing each element individually while the installation is being implemented, aiming to test the fountain’s operation before the final commissioning
• It includes the collecting and management of wind data - the control panel makes ‘decisions’ according to its velocity and direction.
• The touch screen comes in multi-language option. This facilitates its use in different
• All the control system’s configuration menu is password protected.
• The PLC + HMI development makes it possible to record the programmed sequences and send it to other places via Internet (email, file-sending systems…). In order to do so, the recorded information is stored in an external memory so it can be transferred to other installations.