07KT98-GJR5253100R427807KT98-H3 机器人备件

DCS网络的结构形式大致是三种，分别是总线形、环形和星形。星形结构通常只用于小系统。通讯协议有令牌广播式，问询式和存储转发式。问询式协议的网络要有交通指挥器。

所有人机界面要向控制器请求数据时，必需通过交通指挥器，由交通指挥器来向控制器请求数据。控制器才能发送信息给人机界面。如HONEYWELL的TDC2000，FISHER的PROVOX，都有交通指挥器。在星形网络中，人机界面(操作站)可以作为交通指挥器。它只能连接一个人机界面的结点。把它作为操作站。网络的覆盖面也比较小。由一些回路控制器组成的系统通常都连成星形网络。令牌广播式由一个结点发出一个令牌(令牌是特别的比特组，比特组内无源地址和目的地址)，令牌沿环绕行。

拿到这个令牌的结点就改变令牌中一个特定位，将令牌变成一信息帧的帧起始定界符，加挂上构成一帧所需要的其余字段以发送信息，网络上的其它结点都在接收信息。

07KT98-GJR5253100R427807KT98-H3 机器人备件

The structure of DCS network is roughly three forms, which are bus, ring and star. Star structures are usually only used for small systems. Communication protocols include token broadcast, inquiry and store-and-forward. Interrogative protocol networks should have traffic controllers.

When all human-machine interfaces want to request data from the controller, they must pass through the traffic director, and the traffic director requests data from the controller. The controller can send information to the human-machine interface. HONEYWELL's TDC2000, FISHER's PROVOX, both have traffic controllers. In a star network, the human-machine interface (operator station) can act as a traffic controller. It can only connect to one node of the human interface. Use it as an operating station. The network coverage is also relatively small. A system consisting of several loop controllers is usually connected as a star network. Token broadcast is a token issued by a node (a token is a special set of bits, with no source address and destination address within the set), the token along the surrounding row.

The node that gets the token changes a specific bit in the token, turning the token into the frame start delimiter of a message frame, attaching the remaining fields needed to form a frame to send the message, and other nodes on the network are receiving the message.