As the automatic technology comes of age, more and more subways are considering and adopting comprehensive monitoring systems. With this system in place, integrating comprehensive monitoring software and hardware platforms and sharing resources among them are made workable, which facilitates emergency response and handling, and improves overall operation and deployment. Although the implementation scheme of comprehensive rail-transit monitoring system is variously received among the transportation industries in different countries, the majority of subways that had been constructed have adopted the system to varying degrees, which is representative of the trend of subway automatic technology.
KVM Technology Overview
KVM is an abbreviation for keyboard, video and mouse. The centerpiece of KVM technology is the idea that the appropriate configuration of keyboards, mice and videos can realize the centralized administration and control of systems and networks, increase the working efficiency of system administrators, economize on the machine room space and cut down the total ownership costs of networks and servers. A KVM host computer switching system can enable a set or several sets of KVMs to switch between several host computers with different operating systems. Thus it also enables a set of peripherals to visit and operate more than one host computer.
KVM host computer switching system dose not depend on the hardware, operating system or application software of a single computer. Remote workstations or peripherals can do the switching between several host computers by operating buttons of KVM switcher, hot keys of the keyboard or the screen menus. By logging on KVM host computers, remote workstations (or centralized workstations) can have simulated operation on any host computer, including restarting.
The common KVM structure is shown as below.

KVM Used in Subway Comprehensive Monitoring
Strictly speaking, KVM system has already has partial application in comprehensive monitoring. For example, the master and standby servers used in monitoring systems usually use the same set of display devices. The switching between the master server and the standby server is done by the KVM switcher, the details of which are spared here. Given practical management of subway mechanical and electrical equipment, another 2 solutions are worth considering.
1. The system integration and remote maintenance
Comprehensive monitoring systems aim to enable viewing and acquisition of information from different systems. KVM is capable of achieving this function at lower costs. The solution is as follows. Link the terminal workstations to the IP-based KVM host computer. Via KVM networks, the host computer can simulate the function of terminal workstations and achieve the monitoring and control of the devices of different systems.
This solution both achieves the functionality and lowers the costs, from the perspective of management. The IP-based KVM system provides simultaneous access to multiple remote terminals. It also allows the setup of access authority. Besides, the redevelopment of KVM enables access to embedded comprehensive monitoring systems and achieves the administration of ATS signals via workstations. Meanwhile, it is possible to establish virtual channels (Serial over IP, which is similar to network gateway) via KVM administration devices with serial ports (or USBs). Thus it is much easier to maintain remote workstations with devices with serial ports.