【文章內(nèi)容簡介】 evices’ information such as devices’ basic information, variable information, message protocol information, window information and controlling logics. Users of this subsystem, called advanced users, only need to be familiar with information of the kinds of devices. Project configuration subsystem is a developing platform for building a project instance, which simulates the connecting details of field devices. The kinds of devices in the device library are instantiated as stations. Users of this subsystem, called ordinary users, only need to be familiar with the field project instance.The running subsystem reads in the project instance information to build a realtime running platform for monitoring and controlling field devices. Users of this subsystem, called ultimate users, only need to be familiar with their monitoring and controlling tasks.Such architecture of three subsystems is more clearcut, more convenient to users, and more effective than other implementations, such as the ones described by and . In those implementations, the whole system is posed of two subsystems: developing subsystem and running subsystem. That architecture requires users to configure for the whole hardware system by one step in one subsystem, namely the developing subsystem. So, the configuration procedure is more plicated. In our architecture, users can first use one subsystem to configure for the devices, and then another subsystem for configure connections between field devices. What is more, the result of device configuration can be reused for configuring many project instances.IV. DEVICE CONFIGURATION SUBSYSTEMA certain type of device can be abstracted as an object, whose data members describe the device’s basic information, variable information, message protocol information, window information, etc. Whose methods describe the device’s controlling logics, such as malfunction diagnosing, auto alarming, etc. The value of device’s variable is a series of binary bits on the bus (which is referred to as message value in the rest part of this paper) such as “1010b” and decimal numbers in the view of users (which is referred to as variable value) such as “1 ampere”. The transformation between these two forms must obey code conversion formula defined by users through variable configuration. Different values under different units should obey the unit transformation rules (such as “1 ampere equals 1000 milliampere”), specified through the unit configuration.Device configuration subsystem is for configuring such information. Figure 2 describes its architecture. In window configuration, various kinds of window elements are provided, for example: 1, control ponents, such as label, text box, edit box, bo box, realtime curves control, histogram control and action button。 2, virtual instruments, such as voltage meter, current meter and power meter。 3, drawing elements, such as line, arc and rectangle。 4, images in image library。 5, icons in icon library. They can be associated with devices’ variables (via configuring) to reflect field devices’ state. By these elements, along with all kinds of editing operations (copying, moving, grouping, etc.), users can build powerful windows. So, the requirement of richness in customizing the windows for monitoring and controlling is satisfied.This subsystem fulfills patibility to different kinds of devices with different types and different bus protocolsthrough:A. Message Format ConfigurationUsers can define devices’ bus protocols. There are two kinds of messages: Up Message is sent by device to puter。 While down Message es the opposite direction. Message format describes the format of device’s message, including the posing rule of the device’s variables’ message values. For example, for every variable of the device, the offset and length of its message value in the device’s message are defined.B. Code Conversion Formula ConfigurationUsers can define the rules for transforming between message value and variable value. There are two kinds of such formulas: up code conversion formula which defines the mapping relation from message value to variable value and down code conversion formula which defines the opposite mapping relation.C. Unit ConfigurationUsers can define the kinds of units of physical quantities and their quantitative relationships. For example, when configuring the unit kind of voltage, 1 millivolt equals volt and 1 kilovolt equals 1000 volt.V. PROJECT CONFIGURATION SUBSYSTEMThis subsystem is for configuring a project instance according to the actual connecting conditions of field devices. Figure 3 presents its architecture. In the architecture, project tailor instantiates the types of devices in device library to stations (for example, there may be three devices typed breaker, so the device type breaker in device library may has three instances in the project.), according to their actual connecting conditions, and assigns their names (such as”Sta1”), bus addresses, port numbers, etc. YSS2000 provides C2000, a programming language specifically for configuration software. It resembles C and is much simplified. In C2000, many syntax elements and library functions specific to monitoring and controlling systems are provided. For example, the identifier “” refers to station Sta1’s voltage of phase A。 (“Sta1” is declared in project configuration and “Va” is declared in variable configuration.) the executing of library function “write to station()” will send message to field device to change the value of device variables. Users can use C2000 to configure expressions and programs for window elements, code conversion formula and any other monitoring and controlling functions. When it is used in device configuration, station name is omitted. Configuration language greatly facilitates the use of YSS2000 and enhances its functions. Architecture of device configuration subsystem Architecture of proj