Music Fountain Control System

28 Jun 2020

The design of the musical fountain control system largely determines the performance of a music fountain. At present, domestic fountain projects are gradually developing in the direction of intelligence, networking, decentralization, and integration, which also puts forward higher requirements for the control system of the fountain.

The hardware control system of the popular music fountain control system in China mostly uses an Ethernet DIO (Digital Input/Output) card, connects the terminal board and the driver board, and controls the SSR (Solid State Relay) pump and SSR electromagnetic Valve, LED (Light Emitting Diode, light-emitting diode) light; Ethernet DA (Digital/Analog, digital-analog conversion) card is used to control the frequency conversion speed governor; Ethernet motion control card is used to control the stepper motor and one or two-dimensional nozzle; Adopt USB to DMX to generate DMX512 signals to control traditional stage lighting equipment such as computer lights, laser show machines, and flamethrowers. This control system has two defects:

1) In most cases, the Ethernet DIO and DA cards are only equivalent to the physical extension of ISA (Industry Standard Architecture) BUS digital DIO cards. These cards are only responsible for ordinary input and output, and there is no calculation function. For example, to build a running spring with 192 outputs, it is necessary to use three 64-bit Ethernet DIO cards, which will occupy 3 IP (Internet Protocol) addresses, only 24 bytes of data are transmitted, and it must be calculated by the host computer to give Ethernet DIO card refresh output. If a fountain needs 1024 Bit control points, it needs 16 64-bit Ethernet DIO cards. There is a time difference between 16 IP sending data, which is not conducive to the synchronization of fountain devices.

The Ethernet motion control card is equivalent to the Ethernet extension of the PC motion control card. 1. Every step of the two-dimensional nozzle must be directly programmed and controlled by a PC.

Obviously, this design is essentially a centralized control system, although it is convenient to debug, but the efficiency is low.

Failure to give full play to the capabilities of the lower computer also caused difficulties in programming the upper computer.

2)Part of the music fountain control system uses Ethernet DIO cards for control functions, part uses Ethernet motion control cards, and part uses DMX512 signals. There is no complete system and universal standards. The system designed in this way is difficult to connect with the international mainstream stage lighting entertainment system.

DMX512, RDM, ARTNRT, ACN standard introduction:

Introduction to DMX512 standard

The DMX512 (Digital MultipleX-512) standard [1] was first developed by the Engineering Committee of the United States Institute for Theatre Technology (USITT) in 1986 and completed in 1990 to control lighting equipment and transmit digital data Standard. The standard protocol can control 512 dimmers, and the brightness level of each dimmer ranges from 0 to 255. The working principle of this protocol is very simple, that is, the console continuously sends brightness data to 512 dimmers. The DMX512 protocol has been widely recognized by the international industry and is currently in the dimming field of the entertainment industry. It ended the era of incompatibility between analog dimming and products, and at the same time created a new era in which digital dimming and other products are compatible with each other.

RDM protocol introduction

The RDM protocol [3] is a remote device management (Remote Device Management) protocol, which was formulated by the American National Standards Institute (ANSI) and is based on DMX512-A. DMX512-A can be regarded as a DMX for two-way data transmission. Under the RDM protocol, the control system can send requests to the lamps, the lamps can also respond to these requests, and the settings of the lamps can be changed on the console. Each RDM-compatible luminaire can be identified by its built-in unique identification code; the content of the list is also likely to include the luminaire model and the number of DMX fields it requires.

Advanced multimedia network music fountain control system system

Considering the shortcomings of the existing music fountain control system, this paper proposes a more advanced control system. The new control system is compatible with the currently popular ACN (Architecture for Control Networks) [2] and Art-Net [4] control structures, and develops a series of RDM[3]/DMX512 control modules that meet the requirements of fountain control. Such as 24CH DO isolated output module, used to drive SSR equipment load, control equipment (such as lamps, pumps, valves) work; 4CH DA isolated output module is used to control inverter equipment; 4CH motion control module is used to control stepper motors Motion control equipment. Since these modules not only include IO functions, but also have computing power, for example, a 192-channel running spring can be controlled by eight 24CH DO isolated output modules. In parallel computing, the host computer only needs to send two bytes of control words. Yes, therefore, with the above solution, multiple fountains, such as 32, multi-pattern, multi-speed variable fountain control effect can be achieved. In addition, because the addresses of these modules are programmable, they can meet the needs of large quantities and flexible applications; for example, 4096 or 8192 RDM/DMX512 channels can be used to control a music fountain device. Every 512 channels is a domain, which can transmit 512/8 = 64 64Bit Ethernet DIO card data, and different from the Ethernet DIO card, 4096 channels are refreshed at the same time, which is very conducive to the synchronization of fountain equipment. The data of one domain 64Bit Ethernet DIO card needs to be sent in 64 times using 64 IP addresses.

Using the ACN or Art-Net network to generate RDM/DMX512 signals as described above, you can control real-time stage lighting equipment such as computer lights, laser performance machines, and flame-throwing LED dimming lights in real time. Through the flexible programming of the control module, it is possible to effectively control all the fountain equipment, effectively control multiple laser show machines, multiple projectors, etc., to meet the needs of fountain, laser, projection and even pyrotechnics.

Due to the use of RDM/DMX512 control signals that follow international standards, the system can be self-contained or can be docked with international large-scale stage lighting performance systems.

Application of Multimedia Network Music Fountain Control System

In recent years, the company has applied the multimedia network music fountain control system proposed in this article in many international large-scale laser projection fountain projects. Due to the advanced system control system, flexible configuration, reliable operation, precise timing, and delicate performance, it has greatly improved the performance of musical fountains in practice, and has been well received by customers at home and abroad.

In order to build a more perfect multimedia network music fountain control system in the future, the following three points can be considered:

1)The operation parameter monitoring function of the fountain physical equipment needs to be further improved, and the standard fountain physical equipment library file is established;

2)The fountain performance abstract equipment is further improved The library realizes normalized programming and improves the efficiency of on-site programming;

3)In addition, simulation technology can be considered in the future to implement virtual debugging of the fountain.

Keywords: musical fountain

Originally published 28 Jun 2020, updated 28 Jun 2020.