I. Project Background
Elevators are an indispensable component of high-rise buildings and a vertical transportation tool closely related to people's lives. The safe use and management of elevators are directly related to the safety of people's lives and property; therefore, the standardized and scientific management of elevator installation and use is urgently needed. Scientific management is also necessary considering the performance and characteristics of elevators as a modern means of transportation. It is understood that some developed countries developed and applied intelligent elevator safety remote monitoring systems more than a decade ago. These intelligent elevator safety remote monitoring systems integrate geographic information, computer control, and remote communication technologies. Through designated elevator data acquisition devices and information network systems, they transmit the operating status and fault information of elevators distributed in various locations to the monitoring terminal in a timely manner, thereby achieving remote monitoring and control of elevators in various locations.
Overview of Elevator Remote Monitoring System
Elevator remote monitoring systems represent a significant advancement in elevator control technology, marking another major technological leap forward. As the above analysis demonstrates, elevators in intelligent buildings should, of course, be intelligent. Remote monitoring service systems represent a further step beyond traditional remote surveillance. These advanced systems transmit elevator operation and fault information to a remote monitoring center via communication lines, offering real-time data storage, online analysis, online prediction and monitoring, and automatic data report generation. This allows management personnel to address problems. For example, if the car is trapped on a floor due to a door malfunction, the remote maintenance center, after assessing the fault, can remotely open the car and landing doors from the lobby.
In situations where no maintenance personnel are available on-site, trapped passengers can exit the elevator car. If a malfunction necessitates on-site maintenance, a combined approach of "central and on-site engineers" can be used to handle emergencies. To reassure trapped passengers, the central system immediately plays reassuring messages to the elevator car, alleviating anxiety. Besides monitoring operational status, the monitoring and maintenance center can perform rapid emergency stops based on displayed information to prevent accidents. The remote monitoring center continuously monitors the elevator system, knowing its operational status and the nature of any malfunctions at any time. Maintenance personnel or on-site engineers are aware of the required repairs before addressing the issue, reducing maintenance costs and time, making intelligent buildings more user-friendly.
The unique fault information recording database function of the elevator remote monitoring system allows maintenance centers to easily establish a database of elevator operation, faults, and maintenance records. Data such as when a malfunction occurred, when maintenance personnel arrived on-site, and when the elevator returned to normal are all recorded in the database. The provided data records are not simple data lists, but standard database files. Maintenance center operators can use relevant programs to open the database and periodically perform data processing, statistics, and report printing. For example, they can statistically analyze the faults and maintenance status of a specific elevator, a group of elevators, or a specific time period. Through these data files (not just record lists), the operational status and fault conditions of the elevators under the maintenance center's jurisdiction can be clearly understood, and the arrival and maintenance status of maintenance personnel after elevator malfunctions can be scientifically and effectively supervised and managed.
II. Introduction to GPRS
GPRS stands for General Packet Radio Service, a new packet data service. The fundamental difference between GPRS and the existing GSM voice system is that GSM is a circuit-switched system, while GPRS is a packet-switched system. Therefore, GPRS is particularly suitable for intermittent, bursty, or frequent small-volume data transmissions, as well as occasional large-volume data transmissions. This characteristic is well-suited for most mobile internet applications. Compared to the circuit-switched data transmission method of the original GSM dial-up system, GPRS, being a packet-switched technology, has advantages such as "real-time online," "pay-as-you-go billing," "quick login," "high-speed transmission," and "seamless handover."
GPRS theoretically boasts a bandwidth of up to 171.2 Kbit/s, with practical applications achieving approximately 40–100 Kbit/s. Providing TCP/IP connections on this channel allows for applications such as internet connectivity and data transmission. A GPRS modem is a new mobile data communication service that provides a connection between mobile users and the data network, offering high-speed wireless IP or X.25 services. GPRS employs packet switching technology, allowing each user to simultaneously occupy multiple wireless channels, and the same channel can be shared by multiple users, resulting in efficient resource utilization and data transmission rates up to 160 Kbps. Using GPRS technology for packet-based data transmission and reception ensures users are always online and are charged based on data usage, rapidly reducing service costs.
