A terminal resistance automatic matching system and method for PLC expansion bus
A technology for expanding bus and terminal resistance, which is used in general control systems, control/regulation systems, electrical program control, etc.
Active Publication Date: 2018-04-20
深圳市合信自动化技术有限公司
View PDF5 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
However, in the prior art, in a system in which PLCs and expansion modules are cascaded, it is necessary to manually determine which expansion module is the last expansion module, and manually connect the terminal resistor set at the expansion module.
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0021] Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.
[0022] Such as figure 1 As shown in FIG. 1 , it shows a schematic structural diagram of an embodiment of a terminal resistance automatic matching system of a PLC expansion bus provided by the present invention. In this embodiment, the terminal resistance automatic matching system of the PLC expansion bus includes PLC1 and a plurality of expansion modules 2, and the expansion bus is used for cascade connection between PLC1 and the plurality of expansion modules 2; wherein, in one embodiment, the The expansion bus adopts the MLVDS bus, which belongs to the half-duplex communication of the bus topology. The expansion buses mentioned in the following are all described as the MLVDS expansion bus. It can be understood that in other embodiments, other type of bus. The expansion modules 2 are cascaded. Each expansion module is an independent entity and has n...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention discloses an automatic matching system for terminal resistors of a PLC expansion bus. The system comprises a PLC and multiple expansion modules, and the PLC and the multiple expansion modules form a bus topolopy structure through expansion bus concatenation, wherein each expansion module is provided with a forward direction communication interface and a backward direction communication interface, each forward direction communication interface is provided with a first switch, each backward direction communication interface is internally provided with a second switch, and each first switch and the corresponding second switch are connected in parallel and connect a terminal resistor to the expansion bus; the first switches and the second switches are all normally-closed switches, when being plugged into a certain forward direction communication interface, a cable abuts against the corresponding first switch and gets the corresponding first switch to be switched off, and when being plugged into a certain backward direction communication interface, a cable abuts against the corresponding second switch and gets the corresponding second switch to be switched off. The invention discloses a corresponding automatic matching method for the terminal resistors of the PLC expansion bus. By means of the technical scheme of the automatic matching system and method for the terminal resistors of the PLC expansion bus, the terminal resistors can be matched automatically and quickly.
Description
technical field [0001] The present invention relates to the field of programmable logic controller (Programmable Logic Controller, PLC), in particular to a terminal resistance automatic matching system and method of PLC expansion bus. Background technique [0002] In the prior art, PLC is to expand I / O (Input / Output, input or output) points or functions. Generally, various I / O modules or functional modules need to be connected through an expansion bus to form a PLC control system. The expansion bus communicates with I / O modules or function modules. [0003] Existing PLCs and expansion modules use expansion buses such as serial peripheral interface (serial peripheral interface, SPI) or controller area network bus (Controller Area Network, CAN) for connection and communication. In specific applications, in PLC Before communicating with the expansion module, it is necessary to complete the matching process of the terminal resistor. Among them, the terminal resistance is the r...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G05B19/05
CPCG05B19/052G05B2219/1109
Inventor 王精
Owner 深圳市合信自动化技术有限公司