First,DCS'sskeleton-thesystemnetwork,whichisthefoundationandcoreofDCS.網(wǎng)絡(luò)對于DCS整個系統(tǒng)的實時性、可靠性和擴充性，起著決定性的作用，各廠家都在這進行了精心的設(shè)計。Asthenetworkofthesystemforreal-timeDCS,reliabilityandscalability,playadecisiverole,sothemanufacturershavebeencarefulinthisareaofdesign.對于DCS的系統(tǒng)網(wǎng)絡(luò)，它滿足實時性的要求，即在確定的時間限度內(nèi)完成信息的傳送。DCSsystemforthenetwork,itmu
First, DCS's skelet
on- the system network, which is the foundation and core of DCS.網(wǎng)絡(luò)對于DCS整個系統(tǒng)的實時性、可靠性和擴充性，起著決定性的作用，各廠家都在這進行了精心的設(shè)計。
Asthe network of the system for real-time DCS, reliability and scalability, play a decisive role,
sothe manufacturers have been careful in this area of design.對于DCS的系統(tǒng)網(wǎng)絡(luò)，它滿足實時性的要求，即在確定的時間限度內(nèi)完成信息的傳送。DCS system for the network, it must meet the requirements of real-time, that is completed within defined time limits of information transmission.這里所說的“確定”的時間限度，是指在無論何種下，信息傳送都能在時間限度內(nèi)完成，而時間限度則是根據(jù)被控制過程的實時性要求確定的。Here called "OK" time limit refers to whether the circumstances, the information transfer can be completed within this time limit, but this time limit will be under the control of the process to be determined in real-time requirements.，衡量系統(tǒng)網(wǎng)絡(luò)性能的指標(biāo)并不是網(wǎng)絡(luò)的速率，即通常所說的每秒比特數(shù)（bps），而是系統(tǒng)網(wǎng)絡(luò)的實時性，即能在多長的時間內(nèi)確保所需信息的傳輸完成。Therefore, network
performance measurement system is not the network speed indicators, known as bits per second (bps), but the network's real-time system that can ensure long time to complete the required information transmission .系統(tǒng)網(wǎng)絡(luò)還非�？煽浚瑹o論在下，網(wǎng)絡(luò)通信都不能中斷，多數(shù)廠家的DCS均采用雙總線、環(huán)形或雙重星形的網(wǎng)絡(luò)拓?fù)浣Y(jié)構(gòu)。Network also have to be very reliable in any case, network communications are not interrupted, so most manufacturers of DCS were double bus, ring or dual star network topology.滿足系統(tǒng)擴充性的要求，系統(tǒng)網(wǎng)絡(luò)上可接入的最大節(jié)點數(shù)量應(yīng)比使用的節(jié)點數(shù)量大若干倍。Scalability to meet the requirements of the system, the system can access the network should be the maximum number of nodes than the actual number of nodes used in a large number of times.這樣，一可以隨時新的節(jié)點，另一也可以使系統(tǒng)網(wǎng)絡(luò)運行于較輕的通信負(fù)荷，以確保系統(tǒng)的實時性和可靠性。In this
way, one can always add new nodes, it can also make the system run on less communication network load conditions to ensure the system's real-time and reliability.在系統(tǒng)運行過程中，各個節(jié)點的上網(wǎng)和下網(wǎng)是隨時發(fā)生的，特別是操作員站，這樣，網(wǎng)絡(luò)重構(gòu)會經(jīng)常進行，而這種操作絕對不能影響系統(tǒng)的正常運行，，系統(tǒng)網(wǎng)絡(luò)應(yīng)該具有很強在線網(wǎng)絡(luò)重構(gòu)功能。Actual operation in the system process, each node of the Internet and into the net may occur at any time, especially operator station so that network reconfiguration will be conducted frequently, and this operation definitely not influence the systems up and running, so the system network should have a strong online network
