Fire-fighting industrial bus encoding method

Abstract

The invention discloses a fire-fighting industrial bus encoding method comprising the following steps: a fire alarm controller carries out encoding with a low-level pulse of which the duty ratio is below 0.3 as the starting point of bit code division, and synchronizes the signal; (2) during encoding, the bit '0' is determined according to the pulse width between two level falling edges, and the bit '1' is determined according to the pulse width between two level rising edges; and every two falling edges are given a separate synchronization signal during encoding; and (3), the step (2) is repeated, continuous encoding is carried out until encoding is completed, and a code is sent to an intelligent component through a bus. The process is simple. The mode of encoding is easy. The problem that a bus is idle for a long time is avoided while the accuracy of data transmission is ensured. Therefore, the method is suitable for popularization and application.

Description

Technical field [0001] The invention relates to the field of fire protection technology, and in particular to a fire protection industrial bus coding method. Background technique [0002] In the existing fire alarm control system, when using the bus to send codes, the controller host must first pull it up in a low level state. When the host sends a string of data, such as "00101", the start bit of the information transmission For the first bit of data, the time for each bit of data transmission is fixed, so the time for transmitting a string of data is also a fixed value. In this encoding method, the clock may be advanced or delayed in the process of information transmission. Therefore, when encoding, an error occurs during the transmission of the first bit of data, which will cause the entire data encoding process to form a cumulative error. The encoding is incorrect, which reduces the accuracy of the clocks at both ends of the communication, which in turn reduces the accuracy ...

AI Technical Summary

Problems solved by technology

Although in this way, there are synchronous signals generated when the level changes, thereby reducing the error caused by the delay or advance of the clock during encoding, but in each level change period, due to the long idle time, the There will be higher requirements on the capacity of external component capacitors, and the hardware purchase cost will be higher; at the same time, the load capacity of the bus will also deteriorate, resulting in reduced power supply and drive capabilities for back-end devices

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