Application of domestic PLC-IKON Drive PLC in fire protection system
Author: Xiamen IKON Drive Technology Co., Ltd.
1. Keywords: PLC multi-network communication for fire protection system
With the development of the economy, there are more and more buildings in the city, so it is very important to prevent and eliminate fire. The fire self-control system is a system that can prevent and eliminate fire and can automatically extinguish the fire in the early stage of the fire. When a fire occurs, the alarm system sends out a fire signal and informs the fire-fighting automatic control system, which then fires the fire. Now make a detailed introduction to the automatic control fire protection system.
3. Control requirements:
1. This system is used in the fire protection system of a large building. The system has 43 fire-fighting equipment, which are distributed in different places of the building, and the distance between the two equipment is relatively long (tens of meters to hundreds of meters). Now, 43 devices on site should be networked and centrally monitored.
2. In order to ensure the reliability of the work, the center can monitor every device on site. The fire signal can be communicated to the corresponding equipment from time to time, and the corresponding equipment can be controlled to extinguish the fire. At the same time, it is also required that the on-site equipment can not only be controlled by the center, but also can be controlled on site.
3. In order to be able to check the situation of the fire scene first, it must be required to switch the video of the first fire scene to the video, so as to facilitate the checking of the fire and extinguishing conditions on the scene.
4. When the center operates a certain device on site, it should also switch to the video of the current operating device to realize manual control.
5. When a device fails to communicate with the center network, the center and the site must be able to alarm from time to time.
6. In order to ensure the stable control of the center, there must be more than two operating systems.
7. The real-time and reliability of data communication between the center and 43 devices should be guaranteed.
8. Economy and operability are also an important factor in actual construction.
Fourth, the solution:
1. 43 fire-fighting equipment should be connected to the network and the center should be controlled remotely. Taking into account the convenience of cost, wiring and construction, the RS-485 network will be used. Because RS-485 only needs to pull two lines, the wiring is convenient and the cost is relatively low, and the distance of a network span is large, which can be as long as more than 1 km. At the same time, considering the large amount of data in network communication and the large number of units, there are not only switch and digital quantities, but also on-site analog quantities. The real-time communication of a single communication port is not enough. After consideration, it is decided to use three RS-485 networks for communication, which not only ensures the problem of large amount of communication data and real-time performance, but also improves the reliability of work. It also brings convenience to wiring, and multiple networks can be laid.
1. The on-site PLC controls the execution of various actions of a single fire-fighting equipment. The center controls all on-site single equipment through the network. The control program is placed on a single device, and the central PLC is placed on the communication control program.
2. When the center operates which equipment or which area sends out a fire alarm signal, it is necessary to see the first scene through video, so add a video in the center to check the fire situation on site. Because each device has a video, add a video matrix for 43-channel video switching. Automatically switch to the video of which device when a fire occurs or which device is controlled.
3. When the network fails, both the site and the center should have an alarm. Center fault alarm: using the simple communication command of IKON Drive PLC, only one command is needed to complete the communication of each station address, and there is also a flag bit for the success of communication with each communication address, which can be used for Do the center communication failure alarm. In order to achieve an effective alarm between the center and a certain equipment on the scene communication failure. On-site network failure alarm: When the communication with the center is normal, the center will always set “ON” to a certain local M position. The local program will turn the M bit “OFF” for a period of time. If the M bit is not “ON” for a long time, it means that the communication with the center is faulty. This M bit can be used to judge whether the network communication between the site and the center is successful. To do network fault alarm.
4. The center is an important control point, and there must be two or more sets of control methods, so a computer and a touch screen are used in the center to control the center to increase the reliability of the control. The two controls are independent of each other, and can control the same center at the same time. When one of them fails, the other can be controlled, so that the normal operation of the center will not be affected, and the center can be controlled reliably.
To sum up the above requirements, the network diagram of the fire protection system is shown in the following figure:
<1> COM1 and COM2 are the two communication ports of IKON Drive PLC host itself, COM1 port (RS-232) is used for online monitoring with the host computer, and COM2 (RS-485) port is used for the center touch screen connection. Then expand three communication ports (COM3, COM4 and COM5) for networking of 43 fire-fighting equipment’s. Each communication port of IKON Drive can upload and download programs and communication, and supports parallel execution to ensure real-time communication.
<2> The DI module is used to transmit the fire alarm signal to the center, and the center then transmits the fire alarm signal to the corresponding fire fighting equipment through processing, and generates a fire alarm prompt in the center, and outputs the signal of the current fire area through the DO module Give the video matrix, through the video matrix switch the video that is currently on fire in the video TV.
1. Large program capacity: 16K
2. There are many expandable communication ports: 3 communication ports can be expanded to reach 5 communication ports. Each communication supports parallel work, and can upload and download programs or communication.
3. More control points: one host can expand 7 modules
4. Simple communication instructions: One device can complete one instruction, no need to manually control the timing to avoid communication conflicts between ports, and there are flags for whether the communication is successful or not, which facilitates the debugging work of technicians and improves work efficiency.
5. High communication efficiency: The communication program has nothing to do with the scanning cycle. The communication program and other programs are executed in different CPUs, which ensures the real-time communication.
IKON Drive powerful networking and communication capabilities, interval-free communication execution, and easy-to-use communication commands enable this large networking to be realized by RS-485 network, reducing costs, ensuring real-time communication and high reliability. reliability.