WTB (Wire Train Bus) node polling method

Abstract

The invention discloses a WTB (Wire Train Bus) node polling method, which comprises the following steps: Step 1: reading a characteristic period array, the characteristic period array comprising a characteristic period of each slave node; Step 2: acquiring the number of WTB nodes, and judging whether the number of WTB nodes is greater than a preset maximum number of nodes for basic period pollingor not, wherein if YES, Step 3 is performed, otherwise, Step 4 is performed; Step 3: calculating a maximum allowable configuration number of each characteristic period according to data of the characteristic period array, adjusting the number of nodes according to the maximum allowable configuration number of each characteristic period, and then performing Step 4; and Step 4: performing the basicperiod polling on the balanced nodes, and constructing a list of completion periods. The method can ensure that the number of nodes polled in each period is less than or equal to the maximum number ofnodes that can be polled in the period, and avoids the problem of process data loss caused by the fact that the number of nodes to be polled is greater than the maximum number of nodes that can be polled in the period.

Description

technical field [0001] The invention relates to the technical field of rail transit, in particular to a WTB node polling method. Background technique [0002] WTB (Wire Train Bus) is a twisted train bus. The WTB bus is mainly used for train-level communication. Its transmission rate is 1Mbps, which can realize the transmission of process data and message data. The biggest feature of the WTB bus is that it has the function of the initial operation of the train. The function of the initial operation of the train is that when the configuration of the train vehicle changes, it can automatically address the vehicle and form a new train topology structure. This process does not require human participation. Therefore, the WTB bus is especially suitable for train vehicles that require dynamic grouping. [0003] The WTB bus can transmit process data periodically, and its transmission period is an integer multiple of the basic period (25ms), and the maximum length of the transmitted ...

AI Technical Summary

Problems solved by technology

However, when there are many WTB nodes and the characteristic cycle set by the slave nodes is faster and the values ​​are relatively concentrated, the existing WTB node polling method is likely to cause the number of slave nodes that the WTB master node needs to poll to be greater than The maximum number of basic periodic polls, which will cause a part of the slave node's process data to be lost

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