A system of remote monitoring of engineering facilities is composed of several subsystems. They are data acquisition subsystem at the remote site, data transmission subsystem, subsystem receiving and processing the data. Each of the subsystems construing the complex is an essential and integral part of the system of remote monitoring. Let us consider a system of monitoring based on the controllers of the series «Impulse 112».
In this case, the acquisition subsystem will be represented by a controller of the series «Impulse 112» together with the connected sensors, measuring elements and means of fixation of events. A controller of the series «Impulse 112» polls connected sensors and the survey results get stored in the memory to be further sent to a centralized facility for processing and visualization. The device is able to gather status from sensors of the "dry contact" type, analog sensors and digital sensors with the protocol 1-Wire (12V), Modbus or other protocols (such as DLMS/COSEM for interfacing utility meters).
Our equipment provides the capability to connect IP-cameras for taking snapshots on a signal capture from a particular sensor.
The results of measurements from the equipment at location are transferred to the processing centre using the subsystem of data transmission - an important element of the system of remote monitoring. Transmission is performed by one of two paths: a wired Ethernet channel and a wireless GPRS (or CDMA EVDO) link using different protocols based on IP. A special case of the use of the wireless channel is a built-in in certain versions of controllers «Impulse 112» possibility of sending SMS-messages. Furthermore, the subsystem is capable of selecting the data transmission channel depending on the availability status of the remote server - to establish a connection. Thus, automatic switching is provided between the transmission mediums: if data cannot be sent through the Ethernet-connection and it will be sent via the mobile network.
The remote monitoring system can be represented as follows:
The subsystem receiving and processing the data provides reception of information from the object equipment located at remote locations, processing, systematization and visualization of the received information. In fact, it finalises the system of remote monitoring and provides the functionality of submitting of statistics and alarms to external systems through a set of interfaces such as ODBC, SNMP, HTTP, and others. Other component parts comprising the subsystem are a user interface, authentication mechanisms, mechanisms of archiving of information. Processing and visualization of the data occurs with the use of a complex of Web-based applications belonging to the said subsystem using a common interface to the DBMS.