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˫485ͨѶϵͳӦũ⻥վ

ߣƽ ʱ䣺2018-10-25ԴΤֹ
߰˫485ͨѶϵͳӦũ⻥վ˴ͳϵͳͨѶܵĿܣһ485ͨѶģʽͨӲϣͨŵֿʽ·485ͨѶ϶档Ӳģ黯ƣͳһơбƽѾʹáһ·֧תϢȡ˰ȫͿɿԣһ·Ҫڵվݽָ·ǰ֧ҪϢϴʵʱݺϢϴվǰ˺ͺ̨ݽϢݣָʱ·Ϊվܻ绯Զṩļ

ƽ ԴƼ޹˾( 214200)

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ƽ (1976-)Уʦо򣺸Ʒз

ժҪͨѶϵͳӦվ˴ͳϵͳͨѶܵĿܣһ485ͨѶģʽͨӲϣͨŵֿʽ·485ͨѶ϶档Ӳģ黯ƣͳһơѾʹáһ·֧תϢȡ˰ȫͿɿԣһ·Ҫڵվݽָ·ǰ֧ҪϢϴʵʱݺϢϴվǰ˺ͺ̨ݽϢݣָʱ·Ϊվܻ绯Զṩļϡ

0

ĿǰĹվϵͳУϢ绯ܻѾԽԽܵӣʹôΧʹãվҲ⣬漰ϵͳиģϢ͹վǰ˵ĿնϢĴߡߡ˵ȷʽϵͳͨ·485ͨѶʵ֣Ϣϴ´һ·֧תƣһ·ڵվ̨ƣڴͳͨŷʽ·ͨģʽʹϵͳϢݸơܻΪվṩ˻ļϡ

1 ϵͳܹ

ϵͳ֧ܣǶǴٿƺУPLCп䡢䡢⽻վ߷վͼ1ʾٿƺвɼǶǴźţƵ·485ͨѶʵվĺ߷վ֮ݽһ·485ͨѶ·߷վźŽѾõľγȺʱоƬṩʱ䣬֧С̫ܵذԶ̫߶ȽǺͷλǶУֹͣǶɽǶȴȡڶ·485ͨѶ·PLCп䡢⽻վݵĽһҹʱڣʵԶ٣ҹԶҹһںٵȴһԶڵĿʼ쳣վͨͨѶ··ָʵܹٿƺаѵǰ֧Ϣʵʱϴվ[2,3]ϵͳͼ1

2 ٿԭܹ

ٿϵͳAVRôԴḻԼ۱ȸߣȫʵʹ󡣵͹AVR ȽRISCṹ ָ;16 MIPSָٶȣ·ɱ̵USARTڣɹ/ӻģʽSPIڽӿڣڸô·485ͨѶUSARTڣҪʽģ⴮ͨѶվǰ˹ٿƺ󡣸ٿƺзֱ·485ͨѶɼǶǴ˻ãʵʱʾϢ·485ͨѶҪʵ߷վվݽԶƹܣ[3]ǰ˸ٿƺΧܽṹͼ2

3 µ

3.1·485ͨѶӲ໥ģ黯޶ǿܡѡþ߱·UARTӲĴԵ·ƣ·UARTӲȫ˫ʿã߱Ӳֵ֧ż飬֡⣬˲ӲжϷʽAVR߱·UARTӲڣ߱ܣ˹ȥҪģ⴮ͨѶĹ͹Ѷ;·ƥ为迹ƣշƶ˿ڵ[1,2]ص·ĵԭЩʹͨѶĿɿԵõܴߣԶԶģͨѶʽ˫ӲUARTͨѶڴѡú·ļΪʵͨѶṩ˿ɿӲϡ

3.2·485ͨѶͨѶִֿײͬЭ飬󣬴ԵĿ·ͨѶЭ飬Ӳ·ͨѶһ·ǻĿǰҵڵModBusЭ飬ҵͨѶֻҪModBusЭ豸նˣ벻ͬ豸ն֮ݴݡվеͨѶݲɼϵͳӡԻ߼ʵչһ·ΪҵڲԶЭ飬ҪϵͳڲͨѶ䣬Эƶɶ壬ͨѶģʽкܴɶȡ磬ֽΪ豸ַѡۼƷʽЧ飬ӵCRCЧ飬֡ɹ̶ΪijݡпɶݴɣֻҪۼӺͼɣڱϵͳʹ̫ĸ߶ȽǺͷλݣװݣͨѶ֡СӻȶĹд䡢ݽɿϢĴݺͲɼΪϵͳԶܻṩ˱ҪϢ֧֡

4 ԭ

4.1 һ·485ͨѶ·

ͨ룬485ͨѶоƬݽ485оƬABӿͨѶģԽӡA/B ˫TVSܣ˲̬ƸѹͨѶ·쳣ѹڱϵͳв120ŷķƥ迹ͼеR8ʾ485ͨѶоƬ봦֮շ˾룬ǿڱϵͳУշRE/DEоƬķͶˣܿQ1ȷշ״̬л·ϵ·룬PCBռͽʡԪշݾӦUART˿ڡжϻƵĴ£ݵĽպͷ͡

4.2 ڶ·485ͨѶ·

ڶ·485ͨѶڵһ·485·ͼ4ʵ򻯣ȥ벿ֲ֣䣬ΨһǿշֱܿڴĶ˿ڣ4.7 Kȷƽƽȡ·ͨѶ·ϵͳڲͨѶ磬Щȥ룬򻯵·ͳɱԪһ·485·

4.3 ͨѶЭ鲢

ϲжϼӲѯʽ·485ͨѶжϷʽյݣòѯʽݰĽװشͼ5

5

ͨѶϵͳĿǰѾɹɽ̩߹վϵͳãܸ֧ͨ˫485ͨѶϵͳʵʱϴվݹģվĿָʱݵǰܸ֧ܣɶܸ֧ܻܵǶܸ֧ܹϢĻȡΪϵųṩıϡ£ʵʱزܸ֧ܵУ˶еķա˫485ͨѶϵͳܸ֧Ϣϴ´ͨѶṩҪļͨѶ·ǰ˵ĸ̨֧վĺ߷վγһϵͳʵվϵͳܻ绯Զ;ͬΪƼṩ˻ͨѶ·

οף

[1] Richard Anslow. źź͵ԴRS-485ֳߵĸٻ͹Ľ.Τֹ[J].2018,1:76.

[2] . ͼϵͳ.Τֹ[J].2017,8:40.

[3]Ӣ.̫ϵͳʩӦ[M].еҵ, 2014.

ԴڡΤֹ201811ڵ54ҳӭдʱãע



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