Can-bus(Corltroller Area Network)即控制器局域網(wǎng),是國際上應(yīng)用最廣泛的現(xiàn)場總線之一。它是一種多主方式的串行通訊總線,在工業(yè)控制通訊方面擁有高位速率,高抗電磁干擾性,而且能夠檢測出產(chǎn)生的任何錯誤。作為一種靈活,可靠的通訊系統(tǒng),CAN總線已被廣泛運(yùn)用于各個工業(yè)控制現(xiàn)場。 基于FPGA+DSP的CAN總線通訊系統(tǒng)設(shè)計(jì)主要目標(biāo)是完成CAN總線的多節(jié)點(diǎn)可靠高速性傳輸,通過各節(jié)點(diǎn)之間的數(shù)據(jù)通信以及結(jié)點(diǎn)處理單元內(nèi)部對數(shù)據(jù)的處理實(shí)現(xiàn)整個通信系統(tǒng)間各個單元的協(xié)同工作。 本論文中的 CAN 總線通訊系統(tǒng)是完成紅外目標(biāo)探測系統(tǒng)和控制系統(tǒng)與圖像處理系統(tǒng)的實(shí)時通信,其硬件部分采用 DSP+FPGA 作為核心通訊處理單元,通過對 DSP硬件編程和FPGA邏輯模塊的設(shè)計(jì)實(shí)現(xiàn)了在處理單元外部CAN總線多節(jié)點(diǎn)之間的信息可靠性傳輸以及處理單元內(nèi)部DSP和FPGA基于SPI的串行通信,從而完成了在FPGA中對CAN總線數(shù)據(jù)的處理和運(yùn)用。
以太網(wǎng)和CAN總線應(yīng)用廣泛,但由于其通信協(xié)議不同,兩種總線器件間無法進(jìn)行數(shù)據(jù)通信,因此,設(shè)計(jì)了基于CP2200與C8051F040的以太網(wǎng)總線與CAN總線接口轉(zhuǎn)換電路,并給出部分相關(guān)硬件電路與軟件設(shè)計(jì)分析。在保證數(shù)據(jù)完整和協(xié)議可靠的前提下,通過握手協(xié)議和簡化的以太網(wǎng)協(xié)議,不僅實(shí)現(xiàn)了以太網(wǎng)數(shù)據(jù)與CAN數(shù)據(jù)的轉(zhuǎn)發(fā),同時還順利的解決了以太網(wǎng)的高速性與CAN的低速率沖突,以及兩者數(shù)據(jù)包之間的大小不同的矛盾。
Abstract: In the development of actual application, Ethernet and CAN bus are used very extensively. Owing to its various communication protocols, the communicating between two kinds of bus device can’t be carried out. Therefore, in order to solve this problem, the Ethernet-CAN bus interface circuit based on CP2200 and C8051F040 was designed in this paper, and part of the related hardware circuit and software design analysis were given. On the condition of data’s integrity and protocols’reliability, through the handshaking protocols and the simplified the Ethernet protocol, not only the data switching between CAN and Ethernet was realized, but also the differ in velocity and packet size was solved.
介紹一種基于CAN總線的牽引變電站自動化系統(tǒng)通訊規(guī)約的設(shè)計(jì),CAN通訊規(guī)約采用標(biāo)準(zhǔn)幀,報文采用主動發(fā)送和發(fā)送查詢兩種處理形式。該設(shè)計(jì)在城市輕軌與地鐵牽引變電站中的應(yīng)用表明:可實(shí)現(xiàn)間隔層和通訊處理層的數(shù)據(jù)快速、可靠的交換,提高牽引變電站的安全性和穩(wěn)定性
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Abstract:
This paper firstly presents a kind of design dealing with communicational protocol to the traction substation automation system based on CAN bus,and then comes up with the ideas that all frames of CAN communicational protocol should adopt the standard frame,and that messages be processed by two ways:sending initiatively and sending quiries.Subway and light rail application shows that the use of the CAN bus is possible to exchange data quickly and reliably between the layers of the middle and the communicational processing,hence to improve the safety and stability of traction substations.
對于瀝青混凝土攤鋪機(jī)自動找平控制系統(tǒng)來說,數(shù)字式控制系統(tǒng)的研制是目前的一個方向。介紹了一種基于CAN總線的數(shù)字式自動找平控制系統(tǒng)。該系統(tǒng)以CAN總線作為通信方式,PWM控制信號通過C8051F040單片機(jī)內(nèi)部PCA可編程計(jì)數(shù)器陣列產(chǎn)生,并具有結(jié)構(gòu)簡單、信號穩(wěn)定、實(shí)時性強(qiáng)、易擴(kuò)展的特點(diǎn)。通過硬件實(shí)現(xiàn)和系統(tǒng)運(yùn)行達(dá)到了比較理想的控制效果,驗(yàn)證了系統(tǒng)的可行性。
Abstract:
A digital auto-leveling control system based on CAN Bus is introduced.It uses CAN Bus as the method of communication and creates PWM signals by programmable counter array in C8051F040 microcontroller. The system is simple, stable, real-time and expansive.