A kind of address distribution method and plc system

Abstract

The invention discloses an address distribution method and a PLC system. The address distribution method is applied to the PLC system. The PLC system includes at least one PLC and at least two modules, wherein the PLCs form a daisy chain structure with the modules. The address distribution method includes the steps of when address data sent by a component at the previous level of the ith module isreceived, determining the address of the ith module on the basis of the address data, wherein when i is equal to 1, the component at the previous level of the ith module is the PLCs, and when i is greater than 1, the component at the previous level of the ith module is the (i-1)th module; according to a preset data processing method, processing the address data received by the ith module, and obtaining the processed address data; sending the processed address data to the (i+1)th module, wherein i is selected from 1, 2, 3, 4, ... and n-1, and n refers to the number of the modules in the PLC system. According to the scheme, on the premise of reducing modification on hardware of the PLC system, addresses can be distributed for the modules.

Description

technical field [0001] The invention belongs to the technical field of programmable logic controllers, and in particular relates to an address allocation method and a PLC system. Background technique [0002] In the Programmable Logic Controller (PLC) system, a modular system structure is generally adopted, that is, the daisy chain structure of "PLC+module". The PLC accesses each module through the backplane bus, and before accessing the module, Addresses must first be assigned to the individual modules. The traditional method is to add an additional address line to assign an address to the module, or use a chip select signal similar to the Serial Peripheral Interface (SPI) bus, but no matter which method is used above, if the number of modules needs to be expanded, It is necessary to modify the hardware and add more address lines to meet the requirements, and adding additional address lines will inevitably increase the hardware cost, which leads to the weak ability of the ...

AI Technical Summary

Problems solved by technology

The traditional method is to add an additional address line to assign an address to the module, or use a chip select signal similar to the Serial Peripheral Interface (SPI) bus, but no matter which method is used above, if the number of modules needs to be expanded, It is necessary to modify the hardware and add more address lines to meet the demand, and adding additional address lines will inevitably increase the hardware cost, which leads to the weak ability of the traditional method to expand the module address

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