CN101699923A - Lighting control system based on DMX512 protocol and method thereof - Google Patents

Abstract

The invention discloses a light control system and method based on the DMX512 protocol, which includes four parts: a host computer, a DMX signal generator, a DMX signal decoder, and lamps. Each part adopts distributed connection, and the host computer and the DMX signal generator pass through Network connection, the DMX signal generator and the DMX signal decoder are connected through the interface, and the communication between the DMX signal decoder and the lamp adopts a single data bus. Method: The host computer controls the DMX signal generator, the signal generator communicates with the DMX signal decoder, and the signal decoder is connected to the lamp. The invention can configure the baud rate of the communication between the decoder and the lamps online to synchronize DMX devices with different speeds, and has functions such as brightness adjustment of lamps, temperature detection and open circuit detection, and has important reference value for the design of the lighting control system.

Description

A lighting control system and method based on DMX512 protocol

technical field

The invention relates to the technical field of lighting control, in particular to a lighting control system and method based on the DMX512 protocol.

Background technique

LED (Light Emitting Diode, light-emitting diode) is a solid-state electronic device that directly converts electrical energy into light. It has many excellent characteristics such as high efficiency, no pollution, small size, long life and high reliability. Especially in terms of energy saving and service life, LED technology has gradually penetrated into the lighting industry due to its huge potential. LED lighting technology is considered to be one of the new solid cold light sources most likely to enter the field of general lighting in the 21st century and one of the most promising high-tech fields.

The control method of LED lighting products generally adopts the bus control method and the SPI (Serial Peripheral Interface, serial peripheral interface) cascade control method. Under the SPI control mode, the lamps are cascaded one by one, and the damage of any lamp will directly affect the use of the subsequent lamps, and the reliability is low. The bus mode is generally controlled by the DMX512 bus protocol. The DMX512 bus protocol is a stage lighting control protocol released by USITT (American Theater Technology Association) in 1986. It has become an international standard protocol and is widely used by various lighting control systems. The standard DMX512 bus protocol stipulates a data frame of a specific length, and the data capacity of each data frame is 513 bytes, which includes a start code of one byte. The baud rate of the standard DMX512 protocol communication is 250kbps. Although the communication baud rate specified in the standard is 250kbps, with the development of electronic technology, the system can communicate at a higher baud rate. Users can set the specific communication baud rate by themselves according to actual requirements.

The DMX512 bus protocol is used for control. Each product must be set with a unique address. In the traditional DMX512 system, the address of the lamp is generally written into the non-volatile memory. The device needs to be removed and re-addressed, which brings great inconvenience to the maintenance of the system. The traditional DMX512 control system usually uses a one-way transmission function, which cannot read the working status of the lamps in real time, which brings great difficulties to the troubleshooting of on-site faults.

Contents of the invention

The purpose of the present invention is to propose a lighting control system and method based on the DMX512 protocol for the problems existing in the traditional DMX512 lighting control system, thereby solving the problems of the traditional DMX512 lighting control system.

The invention provides a lighting control system based on the DMX512 protocol, which includes four parts: a host computer, a DMX signal generator, a DMX signal decoder, and a lamp. Each part adopts a distributed connection, and the host computer and the DMX signal generator are connected through a network. The DMX signal generator and the DMX signal decoder are connected through an interface, and the communication between the DMX signal decoder and the lamp adopts a single data bus.

Each part of the system adopts distributed connection and is responsible for the following tasks:

(1) The host computer is responsible for configuring the parameters of the DMX signal generator online and monitoring the working status of the lamps;

(2) The DMX signal generator is responsible for sending standard DMX signals;

(3) The DMX signal decoder is responsible for decoding the received DMX signal, and sends the received signal to the lamp after frequency modulation;

(4) The lamp adjusts the working parameters according to the received DMX signal, and returns the working information of the lamp according to the requirements.

Described upper computer and DMX signal generator are connected by Ethernet interface, and its communication protocol adopts TCP/IP protocol, and DMX signal generator and DMX signal decoder (103) are connected by 5-wire DMX512 interface, realize two-way data communication.

The hardware structure adopted by the DMX signal decoder and the lamp is a universal asynchronous UART serial interface.

The communication between the DMX signal decoder and the lamp adopts a single data bus to realize two-way asynchronous data transmission, and the communication link design adopts signal amplification and power buffer circuit to realize long-distance signal transmission.

The data transmission between the DMX signal decoder and the lamp adopts the neutral line as the reference ground.

The host computer is an ordinary PC.

A lighting control system method based on the DMX512 protocol, the process is as follows:

The communication between the DMX signal decoder and the lamp adopts the half-duplex mode. The DMX signal decoder transmits the configuration or dimming signal sent by the controller through the bus, and the lamp returns the response information to the DMX signal decoder through the bus, and the DMX signal decoder then transmits The response information is forwarded to the DMX signal generator and finally received by the host computer. Each lamp is configured with an independent lamp address, and the method of time-division multiplexing is used to compete for the bus without interfering with each other.

When the system is working normally, the upper computer configures the working parameters of the DMX signal generator in real time, sets the data frame header time of the DMX signal, and the baud rate of the signal transmission, and the DMX signal generator sends the DMX512 data frame through the RS485 interface; usually, the The signal baud rate is set to 250kbs, one frame of data is 513 bytes, one byte of start code, and 512 bytes of data; the start code is used to identify the specific meaning of the subsequent data of each frame of data start code, used for Distinguish dimming information, modify lamp information, read lamp information, configure different information, and the whole system works normally. First, configure some basic information, lamp address, communication baud rate, and each lamp is connected to the system. The configuration information must be written in advance. When writing configuration information, only one lamp is allowed on the bus. The lamp configuration command frame consists of the start code of the frame flag field, the data frame length field, the lamp model field, the control program version number field, and the lamp address. field and frame check field;

When the DMX signal generator sends data in the above frame format, the DMX signal decoder detects the 5A start code, judges that the data in this frame is a data frame for configuring lamp information, and forwards the data to the lamp, and the lamp according to the received information , write the configuration information to the non-volatile memory, after writing the configuration information, the lamps will send back the response data frame to the DMX signal decoder, and the DMX signal decoder will forward the response information to the host computer through the DMX signal generator, and the host computer software According to the received data, it is judged whether the configuration of the lamp information is successful. The response data frame of the lamp configuration information is composed of the start code of the frame flag field, the data frame length field, the configuration success response field and the frame check field;

After writing the configuration information of the lamps, the lamps can be connected to the system. The data bus of each DMX signal decoder is connected to several lamps. The addresses of the three DMX signal decoders are configured through hardware. Each DMX signal The decoders are responsible for several lamps within the address range. After the system is installed, the following operations can be realized: modify the system communication baud rate, modify the address of the lamp, read the working parameters of the specified lamp, and adjust the brightness of the lamp. The above four are described in detail below. kind of operation;

(1) Modify the system communication baud rate

When the system is powered on, the system communication baud rate is fixed. When the system is running, if the communication baud rate needs to be modified, the data frame for modifying the communication baud rate consists of the start code of the frame flag field, the data frame length field, the baud Rate value field and frame check field;

The DMX signal decoder receives the frame data, sends the frame data to the lamp at the same baud rate, and immediately modifies the baud rate of the communication with the lamp after sending, and immediately modifies the current communication wave after the lamp receives the frame data Baud rate, the data frame returned to the DMX signal decoder is composed of the start code of the frame flag field, the data frame length field, the baud rate value field and the frame check field;

If the upper computer does not receive the response frame, it considers that the modification is invalid. When the system is reset, the system communication baud rate returns to the default value.

(2) Modify the lamp address

Modifying the address of lamps is a common operation for system maintenance. The instruction frame to define the address of modifying lamps is composed of the start code of the frame flag field, the length field of the data frame, the address field of the lamp to be modified, the new address field of the lamp and the frame check field;

When the DMX signal decoder receives the frame data, it forwards the data to the lamps at the preset baud rate, and the lamps that meet the address requirements receive the data frame and rewrite the non-volatile register, and return the response information data frame after the modification is successful , the response command frame is composed of the start code of the frame flag field, the data frame length field, the address field of the lamp to be modified, the new address field of the lamp and the frame check field;

(3) Read the working parameters of the specified lamp

Real-time monitoring of the working parameters of the lamps is an important basis for system maintenance. The staff can set the upper computer software to send corresponding data frames, requesting the lamps to send back the current working information, and the instruction frame for correspondingly reading the working parameters of the lamps is determined by the frame flag field The start code, the data frame length field, the address field to read the lamp information and the frame check field;

When the DMX signal decoder receives the frame data, it forwards the data to the lamps at the preset baud rate, and the lamps that meet the address requirements receive the data frame and send the corresponding response data frame to read the data of the specified lamp working parameters The frame format consists of the start code of the frame flag field, the data frame length field, the lamp model address field, the control program version field, the lamp current temperature field, the LED open circuit status indication field, the lamp address field and the frame check field;

If the DMX signal decoder does not receive the response data frame within a certain period of time, the DMX signal decoder will continue to receive the DMX signal from the DMX signal generator and forward it to the lamp again. If the response message is not received for 3 consecutive times, it will be considered The line is abnormal or the lamp is not working properly.

(4) Adjust the brightness of the lamp

Adjusting the brightness of lamps is the core work of the system. The standard DMX signal contains 512 bytes of data. Each DMX dimming data frame can control up to 512 channels. Each lamp occupies 3 channels, and the 3 channels correspond to the red color of the lamp. , green, and blue primary colors, the total light brightness information of the entire system, the dimming data frame contains 513 bytes, the first byte is the start code of the DMX data frame 00H, and the 1st to 450th bytes correspond to the 1- Dimming information of 450 DMX channels, the first channel corresponds to the red dimming parameter of the first lamp, the second channel corresponds to the green dimming parameter of the first lamp, and the third channel corresponds to the blue dimming parameter of the first lamp Optical parameters, and so on, the 451st to 512th bytes are spare bytes;

When the DMX signal decoder receives the dimming data frame, it forwards the dimming information according to the lamps within the address range it is responsible for, reducing the baud rate of the communication between the DMX signal decoder and the lamps, thereby reducing the interference of data transmission and improving the system When the lamp receives the data frame, it intercepts the three-byte dimming information belonging to its own address range, and configures PWM to dim the three LEDs.

The DMX signal decoder analyzes the standard DMX signal, performs frequency modulation on the received signal, sends the modulated signal to the lamp at a rate that meets the system transmission, and can demodulate the information returned by the lamp into a standard DMX signal and return it For the DMX signal generator, it acts as a data transmission repeater.

The address of each lamp is programmed online, and the host computer monitors the working status of each lamp in real time.

Beneficial effect

The light control system based on the DMX512 protocol provided by the present invention can well realize functions such as light control, online modification of lamp addresses, and real-time reading of lamp working information. And a single data bus transmission scheme is proposed, which reduces the wiring cost of the system and reduces the interference of long-line transmission at the same time. It has important reference value for the design of lighting control system.

Description of drawings

Fig. 1 is the structural diagram of the lighting control system based on the DMX512 protocol of the present invention;

Fig. 2 is a system circuit diagram of the lighting control system based on the DMX512 protocol of the present invention.

Detailed ways

The gist of the present invention is to design a lighting control system based on the DMX512 protocol. The following will be described in detail in combination with specific implementation methods, so as to have a more in-depth interpretation of the technical features and advantages of the present invention.

The system structural diagram of the present invention is as accompanying drawing 1. The lighting control system of the present invention includes four parts: a host computer 101 , a DMX signal generator 102 , a DMX signal decoder 103 and a lamp 104 . The host computer 101 can be an ordinary PC (internal setting control software), and the host computer software is mainly responsible for configuring the working parameters of the DMX signal generator 102 and monitoring the working status of the lamps. The upper computer 101 is connected with the DMX signal generator 102 through an Ethernet interface, and its communication protocol adopts the TCP/IP protocol, and the upper computer software configures the parameters of the DMX signal generator 102 through the Ethernet interface. The DMX signal generator 102 and the DMX signal decoder 103 are connected through RS485 and 5-wire DMX512 interfaces to realize two-way data communication.

The communication between the DMX signal decoder 103 and the lamp 104 follows the DMX512 protocol. The three DMX signal decoders 103 are connected to the DMX signal generator 102 by bus. The three DMX signal decoders are equal in status and assigned independent addresses. The DMX signal decoder 103 is connected to the lamps through a UART. The interface between the lamps 104 and the DMX signal decoder 103 is also a UART. 50 lamps are connected to the DMX signal decoder in the form of a bus. The entire system Can control 150 lamps.

Light fixtures 104 are RGB light fixtures.

A lighting control system method based on the DMX512 protocol, the process is as follows:

The communication between the DMX signal decoder 103 and the lamp 104 adopts half-duplex mode. The DMX signal decoder can transmit the configuration or dimming signal sent by the controller through the bus, and the lamp returns the response information to the DMX signal decoder through the bus, and the DMX signal is decoded. The generator then forwards the response information to the DMX signal generator and finally receives it for the host computer. Each lamp is configured with an independent lamp address, and the method of time-division multiplexing is used to compete for the bus without interfering with each other.

When the system is working normally, the upper computer 101 configures the working parameters of the DMX signal generator 102 in real time, such as setting the data frame header time of the DMX signal, the baud rate of the signal transmission, etc. DMX signal generator sends DMX512 data frame through RS485 interface. Normally, the signal baud rate is set to 250kbs, one frame of data is 513 bytes, one byte of start code, and 512 bytes of data. The start code is used to identify the specific meaning of the subsequent data of each frame data start code, and is used to distinguish a series of different information such as dimming information, modifying lamp information, reading lamp information, and configuration information. For the whole system to work normally, some basic information must be configured first, such as lamp address, communication baud rate, etc. Each light fixture must have pre-written configuration information before it is connected to the system. When writing configuration information, only one fixture is allowed on the bus. The lamp configuration instruction frame is composed of the start code of the frame flag field, the data frame length field, the lamp model field, the control program version number field, the lamp address field and the frame check field;

For example, the format of the lamp configuration instruction frame is as follows:

SYN PKLEN Data CHKSUM start code packet length data checksum

Slot definition Ranges 0 Start Code 5AH 1 Packet Length Low Bit (LSB) 16H 2 Packet Length High Bit (MSB) 00H 3-14 12 bytes ASCII characters of the lamp model 20H-7FH 15-20 ASCII characters for 6-byte program version number 20H-7FH twenty one Lamp Address Low Bit (LSB) 00H-FFH twenty two Lamp Address High Bit (MSB) 00H-FFH 23-24 2-byte simple checksum (CHKSUM), including "packet length" and "packet" all byte data is accumulated and the last 2 bytes are taken. 0000H-FFFFH

When the DMX signal generator sends data in the above frame format, the DMX signal decoder detects the 5A start code, judges that the data in this frame is a data frame for configuring lamp information, and forwards the data to the lamp, and the lamp according to the received information , write the configuration information to the non-volatile memory. After writing the configuration information, the lamps and lanterns send back the response data frame to the DMX signal decoder, and the DMX signal decoder forwards the response information to the host computer through the DMX signal generator, and the host computer software judges the configured lamp information according to the received data. whether succeed. The lamp configuration information response data frame is composed of the start code of the frame flag field, the data frame length field, the configuration success response field and the frame check field;

The format of the light configuration information response data frame is as follows:

Slot definition Ranges 0 Start Code 5BH 1 Packet Length Low Bit (LSB) 06H

Slot definition Ranges 2 Packet length high bit (MSB) 00H 3 The ASCII code of "O" 4FH 4 The ASCII code of "K" 4BH 5 Lamp Address Low Bit (LSB) 00H-FFH 6 Lamp address high bit (MSB) 00H-FFH 7-8 2-byte simple checksum (CHKSUM), including "packet length" and "packet" all byte data is accumulated and the last 2 bytes are taken. 0000H-FFFFH

After writing the configuration information of the lamps, the lamps can be connected to the system. The data bus of each DMX signal decoder can connect 50 lamps, and the total number of lamps that can be installed in the whole system is up to 150. The addresses of the three DMX signal decoders are configured through hardware, and each DMX signal decoder is responsible for 50 lamps within the address range. After the system is installed, the following operations can be realized: modify the system communication baud rate, modify the lamp address, read the working parameters of the specified lamp, adjust the brightness of the lamp, etc. The above four operations are described in detail below.

(1) Modify the system communication baud rate

When the system is powered on, the system communication baud rate is fixed. When the system is running, if you need to modify the communication baud rate. The data frame for modifying the communication baud rate is composed of the start code of the frame flag field, the data frame length field, the baud rate value field and the frame check field;

The data frame format for modifying the communication baud rate is as follows:

Slot definition Ranges 0 Start Code 5CH 1 Packet Length Low Bit (LSB) 06H 2 Packet length high bit (MSB) 00H 3 The lower eight bits of the low byte of the baud rate value 00H-FFH 4 Baud rate value low byte high eight 00H-FFH

Slot definition Ranges 5 Baud rate value high byte low eight 00H-FFH 6 Baud rate value high byte high eight 00H-FFH 7-8 2-byte simple checksum (CHKSUM), including "packet length" and "packet" all byte data is accumulated and the last 2 bytes are taken. 0000H-FFFFH

The DMX signal decoder receives the frame of data, sends the frame of data to the lamp at the same baud rate, and immediately modifies the baud rate of the communication with the lamp after sending, and immediately modifies the wave of the current communication after the lamp receives the frame of data Baud rate, the data frame returned to the DMX signal decoder is composed of the start code of the frame flag field, the data frame length field, the baud rate value field and the frame check field;

The data frame format returned to the DMX signal decoder is as follows:

Slot definition Ranges 0 Start Code 5DH 1 Packet Length Low Bit (LSB) 06H 2 Packet length high bit (MSB) 00H 3 The lower eight bits of the low byte of the baud rate value 00H-FFH 4 Baud rate value low byte high eight 00H-FFH 5 Baud rate value high byte low eight 00H-FFH 6 Baud rate value high byte high eight 00H-FFH 7-8 2-byte simple checksum (CHKSUM), including "packet length" and "packet" all byte data is accumulated and the last 2 bytes are taken. 0000H-FFFFH

If the upper computer does not receive the response frame, it considers the modification invalid. When the system is reset, the system communication baud rate restores to the default value.

(2) Modify the lamp address

Modifying the address of lamps is a common operation for system maintenance. The instruction frame to define the address of modifying lamps is composed of the start code of the frame flag field, the length field of the data frame, the address field of the lamp to be modified, the new address field of the lamp and the frame check field;

The command frame format for defining and modifying the lamp address is as follows:

Slot definition Ranges 0 Start Code 6AH 1 Packet Length Low Bit (LSB) 06H 2 Packet length high bit (MSB) 00H 3 It is necessary to modify the low bit (LSB) of the lamp address 00H-FFH 4 Need to modify the high bit (MSB) of the lamp address 00H-FFH 5 Luminaire New Address Status (LSB) 00H-FFH 6 Lamp new address high bit (MSB) 00H-FFH 7-8 2-byte simple checksum (CHKSUM), including "packet length" and "packet" all byte data is accumulated and the last 2 bytes are taken. 0000H-FFFFH

When the DMX signal decoder receives the frame data, it forwards the data to the lamps at the preset baud rate, and the lamps that meet the address requirements receive the data frame and rewrite the non-volatile register, and return the response information data frame after the modification is successful , the response command frame is composed of the start code of the frame flag field, the data frame length field, the address field of the lamp to be modified, the new address field of the lamp and the frame check field;

The response data frame format is as follows:

Slot definition Ranges 0 Start Code 6BH 1 Packet Length Low Bit (LSB) 06H 2 Packet Length High Bit (MSB) 00H

Slot definition Ranges 3 Low address (LSB) of lamp address before modification 00H-FFH 4 High address (MSB) of lamp address before modification 00H-FFH 5 New address status of lamps after modification (LSB) 00H-FFH 6 After modification, the new address high bit (MSB) of the lamp 00H-FFH 7-8 2-byte simple checksum (CHKSUM), including "packet length" and "packet" all byte data is accumulated and the last 2 bytes are taken. 0000H-FFFFH

(3) Read the working parameters of the specified lamp

Real-time monitoring of the working parameters of the lamps is an important basis for system maintenance. The staff can set the upper computer software to send corresponding data frames, requesting the lamps to send back the current working information, and the instruction frame for correspondingly reading the working parameters of the lamps is determined by the frame flag field The start code, the data frame length field, the address field to read the lamp information and the frame check field;

The lamp is required to send back the current working information, and the command frame for reading the working parameters of the lamp is as follows:

Slot definition Ranges 0 Start Code 7AH 1 Packet Length Low Bit (LSB) 04H 2 Packet length high bit (MSB) 00H 3 Lamp Address Low Bit (LSB) 00H-FFH 4 Lamp address high bit (MSB) 00H-FFH 5-6 2-byte simple checksum (CHKSUM), including "packet length" and "packet" all byte data is accumulated and the last 2 bytes are taken. 0000H-FFFFH

When the DMX signal decoder receives the frame data, it forwards the data to the lamps at the preset baud rate, and the lamps that meet the address requirements receive the data frame and send the corresponding response data frame to read the data of the specified lamp working parameters The frame format consists of the start code of the frame flag field, the data frame length field, the lamp model address field, the control program version field, the lamp current temperature field, the LED open circuit status indication field, the lamp address field and the frame check field;

The data frame format for reading the working parameters of the specified lamp is as follows:

Slot definition Ranges 0 Start Code 7BH 1 Packet Length Low Bit (LSB) 18H 2 Packet length high bit (MSB) 00H 3-14 ASCII characters of 12-byte lamp model 20H-7FH 15-20 ASCII character of 6-byte program version number 20H-7FH twenty one 1 byte temperature value (highest bit 1 means negative temperature, 0 means 00H-FFH positive temperature) twenty two 1 byte LED working status* 00H-07H twenty three Lamp Address Low Bit (LSB) 00H-FFH twenty four Lamp address high bit (MSB) 00H-FFH 25-26 2-byte simple checksum (CHKSUM), including "packet length" and "packet" all byte data is accumulated and the last 2 bytes are taken. 0000H-FFFFH

If the DMX signal decoder does not receive the response data frame within a certain period of time, the DMX signal decoder will continue to receive the DMX signal from the DMX signal generator and forward it to the lamp again. If the response message is not received for 3 consecutive times, it will be considered The line is abnormal or the lamp is not working properly.

(4) Adjust the brightness of the lamp

Adjusting the brightness of lamps is the core work of the system. The standard DMX signal contains 512 bytes of data. Each DMX dimming data frame can control up to 512 channels. Each lamp occupies 3 channels, and the 3 channels correspond to the red color of the lamp. , green, and blue primary colors, the total light brightness information of the entire system, the dimming data frame contains 513 bytes, the first byte is the start code of the DMX data frame 00H, and the 1st to 450th bytes correspond to the 1- Dimming information of 450 DMX channels, the first channel corresponds to the red dimming parameter of the first lamp, the second channel corresponds to the green dimming parameter of the first lamp, and the third channel corresponds to the blue dimming parameter of the first lamp Optical parameters, and so on, the 451st to 512th bytes are spare bytes;

The dimming data frame format is as follows:

Slots definition Ranges 0 Start Code #00H 1 The lamp with the address "#1" displays data in red 00-FF 2 The lamp with the address "#1" displays data in green 00-FF 3 The lamp with the address "#1" displays data in blue 00-FF 4 The red display data of the lamp whose address is "#2" 00-FF 5 The lamp with the address "#2" displays data in green 00-FF 6 The lamp with the address "#2" displays data in blue 00-FF . . . . . . . . . . . . . . . 448 The red display data of the lamp whose address is "#150" 00-FF 449 The lamp with the address "#150" displays data in green 00-FF 450 The blue display data of the lamp with address "#150" 00-FF 451-512 spare bytes

When the DMX signal decoder receives the dimming data frame, it forwards the dimming information according to the lamps within the address range it is responsible for, reducing the baud rate of the communication between the DMX signal decoder and the lamps, thereby reducing the interference of data transmission and improving the system reliability. When the lamp receives the data frame, it intercepts the three-byte dimming information belonging to its own address range, and configures PWM to dim the three LEDs.

In the above example, a specific communication protocol and frame format are set to illustrate the present invention in more detail, and the communication protocol can be re-set according to different requirements of different occasions in actual application. In a word, those skilled in the art can make various changes and modifications to the communication protocol of the present invention without departing from the spirit and scope of the present invention. If these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

The system circuit diagram of the lighting control system based on DMX512 protocol in Figure 2

Host computer 101 and DMX signal generator 102 are connected through Ethernet interface, and its communication protocol adopts TCP/IP protocol, DMX signal generator 102 and DMX signal decoder 103 are connected through 5-wire DMX512 (RS485) interface, realize two-way data communication.

The hardware structure adopted by the DMX signal decoder 103 and the lamp 104 is a general asynchronous serial interface.

The communication between the DMX signal decoder 103 and the lamp 104 adopts a single data bus to realize two-way asynchronous data transmission, and the communication link design adopts signal amplification and power buffer circuit to realize long-distance signal transmission.

The data transmission between the DMX signal decoder 103 and the lamp 104 uses the neutral line as a reference ground.

The DMX signal decoder 103 analyzes the standard DMX signal, performs frequency modulation on the received signal, sends the modulated signal to the lamp at a rate consistent with the system transmission, and can demodulate the information returned by the lamp into a standard DMX signal Return to the DMX signal generator and play the role of data transmission repeater.

The address of each lamp 104 is programmed online, and the host computer 101 monitors the working status of each lamp in real time.

Claims (10)

1. lamp light control system based on the DMX512 agreement, comprise host computer (101), DMX signal generator (102), DMX decoding signals (103), (104) four parts of light fixture, it is characterized in that, various piece adopts distributed connection, host computer (101) is connected by network with DMX signal generator (102), DMX signal generator (102) is connected by interface with DMX decoding signals (103), and communicating by letter between DMX decoding signals (102) and the light fixture (104) adopted the forms data bus.

2. the lamp light control system based on the DMX512 agreement according to claim 1 is characterized in that system's each several part adopts distributed connection, respectively the following work of Fu Zeing:

(1) host computer (101) is responsible for the parameter of Configuration Online DMX signal generator and is monitored the light fixture operating state;

(2) DMX signal generator (102) is responsible for the DMX signal of transmission standard;

(3) DMX decoding signals (103) is responsible for the DMX signal decoding to receiving, and the signal that receives is carried out sending to light fixture after the frequency modulation(FM);

(4) light fixture (104) is adjusted running parameter according to the DMX signal that receives, and returns the job information of light fixture as requested.

3. the lamp light control system based on the DMX512 agreement according to claim 1, it is characterized in that, described host computer (101) is connected by Ethernet interface with DMX signal generator (102), its communication protocol adopts ICP/IP protocol, DMX signal generator (102) is connected by 5 line DMX512 interfaces with DMX decoding signals (103), realizes bidirectional data communication.

4. the lamp light control system based on the DMX512 agreement according to claim 1 is characterized in that, described DMX decoding signals (103) is universal asynchronous UART serial line interface with the hardware configuration that light fixture (104) adopts.

5. the lamp light control system based on the DMX512 agreement according to claim 4, it is characterized in that, communicating by letter between described DMX decoding signals (103) and the light fixture (104) adopts the forms data bus to realize two-way simultaneous asynchronous data transmissions, the communication link design adopts signal to amplify and the power buffer circuit, realizes the signal long-distance transmission.

6. the lamp light control system based on the DMX512 agreement according to claim 5 is characterized in that, the transfer of data between described DMX decoding signals (103) and the light fixture (104) adopts zero line as reference ground.

7. according to each described lamp light control system of claim 1～3, it is characterized in that described host computer (101) is a common PC based on the DMX512 agreement.

8. lamp light control system method based on the DMX512 agreement, its process is as follows:

DMX decoding signals (103) adopts semiduplex mode with communicating by letter of light fixture (104), configuration or dim signal that the DMX decoding signals sends by the bus transmitting controller, light fixture (104) returns to the DMX decoding signals by bus with response message, the DMX decoding signals is transmitted to response message the DMX signal generator again and finally receives for host computer (101), each light fixture disposes independently light fixture address, adopt the method contention bus of time-sharing multiplex, do not disturb mutually

During the system operate as normal, host computer (101) disposes the running parameter of DMX signal generator (102) in real time, and the data frame head time of DMX signal is set, the baud rate that signal sends, and the DMX signal generator sends the DMX512 Frame by the RS485 interface; Generally, the signal baud rate is set to 250kbs, 513 bytes of frame data, the initial code of a byte, 512 byte datas; Initial code is used to identify the concrete implication of the follow-up data of every frame data initial code, be used to distinguish light modulation information, revise light fixture information, read light fixture information, the information that configuration information is different, the whole system operate as normal, at first to dispose some basic information, the light fixture address, communication baud rate, each light fixture must be finished writing configuration information in advance before being articulated to system, when writing configuration information, only allow a light fixture on the bus, light fixture configuration-direct frame is by the initial code of flag of frame field, Frame length field, light fixture model field, the control program version number field, light fixture address field and frame check field are formed;

When the DMX signal generator sends the data of above-mentioned frame format, the DMX decoding signals detects the 5A initial code, judge that these these frame data are configuration light fixture information data frame, and give light fixture with this data forwarding, light fixture is according to the information that receives, configuration information is written to nonvolatile storage, write after the configuration information, light fixture postbacks the reply data frame and gives the DMX decoding signals, the DMX decoding signals is transmitted to host computer by the DMX signal generator with response message, upper computer software is according to the data of receiving, whether light fixture information is this time disposed in judgement successful, and light fixture configuration information reply data frame is by the initial code of flag of frame field, Frame length field, configuration successful acknowledgement field and frame check field are formed;

After writing the configuration information of light fixture, just light fixture can be articulated in the system, the data/address bus of each DMX decoding signals articulates several light fixtures, hardware configuration is passed through in the address of three DMX decoding signals, each DMX decoding signals is responsible for several light fixtures in the address realm separately, after system installs, can be achieved as follows operation: revise the system communication baud rate, revise the light fixture address, read the running parameter of specifying light fixture, regulate lamp brightness, specify above four kinds of operations below;

(1) revises the system communication baud rate

When system powered on, the system communication baud rate was fixed, and when system moves, if need to revise communication baud rate, revised the Frame of communication baud rate and was made up of initial code, Frame length field, baud rate value field and the frame check field of flag of frame field;

The DMX decoding signals receives this frame data, send these frame data to light fixture with the baud rate before not changing, send the baud rate that modification is immediately communicated by letter with light fixture, light fixture is received the baud rate of revising current communication behind these frame data immediately, returns to the Frame of DMX decoding signals and is made up of initial code, Frame length field, baud rate value field and the frame check field of flag of frame field;

If host computer do not receive this acknowledgement frame, think and this time revise invalidly that during system reset, the system communication baud rate reverts to default value,

(2) revise the light fixture address

Revising the light fixture address is the common operation of system maintenance, definition revise the command frame of light fixture address by initial code, the Frame length field of flag of frame field, need to revise light fixture address field, the new address field of light fixture and frame check field and form;

When the DMX decoding signals is received these frame data, give light fixture with predefined baud rate with data forwarding, the light fixture that meets the address requirement receives this Frame and rewrites non volatile register, echo reply information data frame after revising is successfully replied command frame and is made up of initial code, Frame length field, need modification light fixture address field, the new address field of light fixture and the frame check field of flag of frame field;

(3) read the running parameter of specifying light fixture

It is the important evidence of system maintenance that the running parameter of light fixture is monitored in real time, the staff can be provided with upper computer software and send corresponding Frame, require light fixture to postback current job information, the corresponding command frame of light fixture running parameter that reads is made up of initial code, Frame length field, the address field that need read light fixture information and the frame check field of flag of frame field;

When the DMX decoding signals is received these frame data, give light fixture with predefined baud rate with data forwarding, the light fixture that satisfies the address requirement receives this Frame and sends corresponding reply data frame, reads and specifies the data frame format of light fixture running parameter to be made up of initial code, Frame length field, light fixture model address field, control program version field, light fixture Current Temperatures field, LED open-circuit condition indication field, light fixture address field and the frame check field of flag of frame field;

If the DMX decoding signals is not received this reply data frame within a certain period of time; the DMX decoding signals can continue to receive the DMX signal of DMX signal generator and be transmitted to light fixture once more; do not receive response message if send continuously 3 times, think that then unusual or this light fixture of circuit is in abnormal operating state.

(4) regulate lamp brightness

Adjusting lamp brightness is the work of the core of system, the DMX signal of standard comprises the data of 512 bytes, every frame DMX light modulation Frame can be controlled 512 passages at most, each light fixture takies 3 passages, 3 corresponding light fixture tools of passage are red, green, primary colors, whole system lamplight brightness information altogether, light modulation Frame lattice contain 513 bytes, first byte is DMX Frame initial code 00H, the light modulation information of the 1st to the 450th corresponding 1-450 the DMX passage of byte difference, the red color tone optical parameter of corresponding first light fixture of first passage, the green hue optical parameter of second corresponding first light fixture of passage, the 3rd corresponding first light fixture blue cast optical parameter of passage, by that analogy, the 451st to 512 byte is spare bytes;

When the DMX decoding signals is received the light modulation Frame, transmit light modulation information according to the light fixture of self being responsible in the address realm, reduced the baud rate of DMX decoding signals with light fixture communication, thereby reduce the interference of transfer of data, the reliability of raising system, when light fixture was received this Frame, intercepting belonged to the light modulation information of three bytes of address realm own, and configuration PWM carries out light modulation to three paths of LEDs.

9. the lamp light control system method based on the DMX512 agreement according to claim 8, it is characterized in that, DMX decoding signals (103) is resolved the DMX signal of standard, carry out frequency modulation(FM) to the received signal, the speed that signal after the modulation is transmitted with a kind of compliance with system sends to light fixture, and the demodulates information that light fixture can be returned is that standard DMX signal returns to the DMX signal generator, plays the effect of data link.

10. the lamp light control system method based on the DMX512 agreement according to claim 8 is characterized in that the address of each light fixture (104) is an online programming, and host computer (101) is monitored the operating state of each light fixture in real time.

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