Design and implementation of elevator monitoring system in building automation

At present, the elevator group control system in China has been widely used, but the remote monitoring of group-controlled elevators has yet to be studied and developed. Therefore, the realization of remote monitoring of group-controlled elevators is more realistic and can better reflect the humanized service of contemporary society.

1. Overview of elevator monitoring system

Classification of elevator monitoring systems at present:

1. At present, most domestic and foreign elevator companies have their own monitoring systems, but such monitoring systems are only developed for their own brands, and various systems are incompatible with each other, which are subject to many restrictions in application.

2. Network communication monitoring composed of PLC. PLC can easily form a system. The development of such a system completely saves the cost of hardware development. As long as the software development is mature, it can be installed. Moreover, the system generally adopts a standard communication interface, which is easy to form a network with other intelligent devices in the building, but the cost is high. However, as the price of PLC drops, it is also a good method.

3. Use a single chip to form an independent sampling communication unit to form a two-level monitoring system. The initial development cost (including hardware and software) of such monitoring is high, but after the system is formed, the cost of resale is very low. However, due to the small market and difficulty in scale formation, most systems do not use standard accessories, which makes maintenance difficult in the future. It can be seen that none of the above methods is an ideal form.

2. Design of elevator monitoring system

(I) Composition and principle of elevator monitoring system

The composition of the elevator operation monitoring system is shown in Figure 1, which mainly includes the central dispatching unit, the acquisition unit, the transmission bus and the field controller. It is characterized by: ① The central dispatching unit is responsible for realizing the group control function of the elevator (through the method of learning, using and acquiring experience knowledge, that is, the self-learning of the system, and then according to the current status information of each elevator, a certain deployment strategy is adopted, and the algorithm is used to analyze which elevator responds to the call to make the elevator system get the best performance, and then this signal is distributed to the corresponding controller); ② The data acquisition unit is mainly responsible for the collection of elevator status information; ③ The bus is used for data transmission between the central dispatching unit and the acquisition unit and remote monitoring.



Here we focus on the communication between the elevator system and the monitoring center, as well as the specific implementation of the monitoring system in the upper computer. The remote monitoring of elevator systems is generally realized in the building automation system (BAS). Of course, it can also be realized through the interface provided by the elevator system and integrated with the building management system (BAS).



What kind of communication the elevator controller and the BA system adopt is the key to realize remote monitoring. The elevator system provides RS232 or RS485 interfaces, etc., directly to the monitoring center, which will be limited by the transmission distance of RS232 or RS485. Although the conversion module can realize the conversion from RS485 to TCP/IP to achieve long-distance transmission, when there are multiple elevators, especially when the distance between buildings is far, it will waste wires. Therefore, the advantages of each dispatching machine first networking and then going to the monitoring center are particularly prominent, as shown in Figures 2 and 3. Of course, in this case, the optical fiber of the integrated wiring can be used for data transmission. The weak current system can use the optical fiber of the integrated wiring, which will also be a development direction of the weak current system of the intelligent building. [page]



(II) Implementation of remote monitoring in the upper computer

Remote monitoring of elevators can be realized by writing simple program codes through Vb or Vc. In VB6O, MSC0mm is used for communication programming. The necessary settings are made for the CommPort, Setting, Portopen, InBufferCount, and InputLen properties of the control to receive the information sent by the elevator, and then the required information is obtained through decoding. However, when using the MSC0mm control to receive data, due to the limited number of COM ports, the number of elevators to be monitored is also limited accordingly. Only 8 elevators can be monitored, which is not easy to use when monitoring multiple elevators; by using the Winsock control, up to 256 elevators can be monitored. Therefore, it is best to use the Winsock control when monitoring multiple elevators.

According to the interface protocol characteristics of the elevator (Guangzhou Hitachi Elevator) used in a certain building complex in Shenzhen, when it is necessary to obtain the elevator data, a request call should be issued to the elevator first, and the elevator will send data after receiving the call information. Directly use the Sendoata function of the Winsock control to issue a call, and use the OataArrlval event to obtain data. Open the Winsock connection as follows:

tcpclientRomoteHost = 19216802"The data can be read from the system database.

TcpclientRemotePort = 4010

TcpclientConnect

uses the control function Getoata to obtain the elevator data and put it into strTemp:

Private Sub tcpclient_DataArrival (ByVal bytestTotal As Long) Dim strTemp () As Byte

Tcpclient GetData strTemp

StrCat ReceiveBuffer, strTemp"The StrCat function connects the Byte type data.

RefreshDisplay strTemp " RefreshDisplay is a decoding function. Through the decoding function, the information represented by the corresponding bit can be determined, so as to obtain the correct elevator data.

End Sub

Since we need to obtain the real-time data of the elevator, we can use the clock control in VB6O to send out call data at appropriate time intervals so as to update the monitoring data in time. By using tools such as Vb and Vc to create a beautiful operation interface, and then writing the corresponding interface program, we can achieve communication connection with well-known integrated systems such as Honeywell, Siemens and Jonhnson Controls to achieve system integration. Considering the stability and openness of the system, we use Moxa card OE311 to realize the conversion of data information to Ethernet. Each elevator interface uses an OE311 to transmit RS485 or RS232 data information to Ethernet, and the elevator management program monitors multiple elevators in a unified manner. The system is equipped with a dedicated elevator management workstation, and uses a monitoring program to manage the data of multiple elevators in a unified manner, which is open to the integrated server in the form of OPC server. On the integrated system server, through OC The client program monitors the elevator in real time and displays it in a graphical form on the integrated platform.

III. System Optimization

In the future, elevator monitoring will inevitably develop in the direction of humanization and comfort. Therefore, it is more important to realize wireless remote control of the system (when the elevator fails, the elevator can send fault information to the mobile phone through a wireless device, and send signals to the mobile phone to simply control the elevator, making the system more humanized); of course, passenger identification system, fingerprint identification system, digital intelligent safety control technology (through passenger identification system or IC card and digital monitoring equipment, outsiders are refused to enter), so that the system can provide humans with safer and more comfortable services.

IV. Conclusion

First, the signal acquisition unit of the elevator operation monitoring adopts photoelectric isolation to completely isolate it from the original elevator system. Secondly, the device adopts a large number of large-scale integrated circuits and advanced printed circuit board technology and the world's most advanced SCM production process, so that its reliability is effectively guaranteed, which is convenient for centralized and real-time monitoring of the operation of the elevator and timely helping maintenance personnel to eliminate elevator failures.