A method for implementing bus control

Abstract

The present invention relates to the field of networking smoke detection, and in particular to a bus control implementation method. The method comprises that: whether the bus protocol is a two-level bus protocol or a three-level bus protocol is determined; relevant parameters are configured; an enable side of a comparator is started; the bus voltage is compared with the threshold voltage; whether the receiving mode is an up mode or a down mode is determined; burr filtering is carried out; and finally a bus communication module carries out communication processing. According to the method disclosed by the present invention, both the two-level bus protocol and the three-level bus protocol can be solved, and burrs with different widths can be filtered out.

Description

technical field [0001] The invention relates to the field of networked smoke detection, in particular to a method for realizing bus control in the field of smoke detection. Background technique [0002] In the field of networked smoke detection, the main controller and each slave detector are generally connected through a two-wire bus. The two-wire bus supports bus protocols with two or three level states. There are only two coding states of 0 and 1 when the two-level bus protocol sends codes, and different codes need to be matched with the length of time, while the three-level bus protocol can have three types of 0, 1, and 2 when sending codes Coding status, more coding can be achieved without matching the length of time. To achieve the same encoding within a period of time, the three-level bus protocol has shorter code length and higher encoding efficiency than the two-level bus protocol, so when the system is implemented, the three-level bus protocol can greatly shorten...

AI Technical Summary

Problems solved by technology

[0004] In addition to the fact that the existing bus control implementation method can only handle two-level bus protocols, there are still the following problems: First, when the host uses different code sending modes to send codes, the existing bus control implementation method adopts the up receiving mode and down receiving mode are processed separately, which wastes the subsequent hardware overhead; second, the interference of noise to communication cannot be eliminated in the bus control. For this problem, the existing method is to provide analog filtering and connect a capacitor externally to the LN24CAP port. However, this method cannot filter out glitches caused by short-term bus voltage fluctuations (wrongly sent codes), code return currents that pull down bus voltages in sending mode, etc.

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