m340 plc和編碼器串行rs485通信采用modbus rtu通信規(guī)約，這個(gè)通訊協(xié)議已廣泛被國內(nèi)外各行業(yè)作為系統(tǒng)集成的一種通用工業(yè)標(biāo)準(zhǔn)協(xié)議，有利于系統(tǒng)的維護(hù)和擴(kuò)展。plc為主站，編碼器為從站。

　　查編碼器技術(shù)手冊，水位測值的modbus地址是4x0000，根據(jù)modbus通信規(guī)約信息幀結(jié)構(gòu)讀取地址 1 傳感器的水位測量值，應(yīng)發(fā)送以下通信碼：m340 plc讀取水位信息主要用read_var功能模塊：140CRA21110分布式I/O  

廈門仲鑫達(dá)自動(dòng)化設(shè)備有限公司

：李素云

企業(yè)QQ：，2851195466

手機(jī)：

：

　　01 03 0000 0001 840a

　　站地址 　功能碼 　　首地址 　　個(gè)數(shù)　　 crc校驗(yàn)碼

　　功能模塊說明[1]

　　adr

　　通信地址：語法為 addm (`r.m.c.node`機(jī)架號.模塊號.通道號.站地址) 類型。

　　obj 要讀取的對象類型

　　’%m’：內(nèi)部位

　　’%mw’：內(nèi)部字

　　’%s’：系統(tǒng)位

　　’%sw’：系統(tǒng)字

　　num 讀取的個(gè)對象的索引。

　　nb 要讀取的對象的數(shù)量。

　　recp輸出參數(shù)包含所讀取對象的值的字表。

　　gest交換管理表：4個(gè)字的數(shù)組。

　　表1 交換管理表

Omega FMA5416ST Gas Mass Flow Controller, Gas: N2, Max Gas Pressure: 500psi

　　Allen Bradley 800T-D Mushroom Head E-Stop Button w/800T-XA Contact Block 1NO/1NC

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　　Lot of 2 IDEC RH2B-U DC24V Relays 24VDC Coil 120/240VAC 10A Contacts DPDT

　　THK HRW21CA Carriage on 380mm Long Rail, Dimensions: 21mm x 68mm x 58.8mm

　　Telemecanique LC1 D2510 Contactor 3-Pole + N.O Aux Rated @ 40A 1000V, 120V Coil

　　Lot of 2 IDEC RH4B-U DC24V Relays 24VDC Coil 120/240VAC 7.5/5A Contacts 4PDT

　　New ACE MC75-3 Miniature Shock Absorber 75in-lbs/cycle 0.4" Stroke 1/2-20 Thread

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　　Parker RS33C-DNNPS Stepper Motor, Shaft: 0.375" Diameter, 340VDC Winding

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　　GE Fanuc IC3000CS200H Operator Interface Panel 24VDC 180mAABB A8PU05ABFW02

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　　ABB 3HAC14549-3/09A

　　ABB 3AUA489002B4562

　　ABB 35AE92A

　　ABB 2012AZ10101B

　　ABB 1SAR330020R0000

　　ABB 07SK90R1

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　　ABB 07KT94

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　　ABB 07AI91

　　ABB 07AI90-S

　　ABB 07AC91

　　SMC CXSM10-60 Dual Rod Cylinder, 0.7MPa Max (101psi), 10mm Bore, 60mm Stroke

　　G-Dok GD-80 Footmaster Swivel Caster with Leveling Leg 500kg Capacity per Caster

　　Hose Master Stainless Corrugated Hose With Stainless Steel Braid, 36" Long

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　　Flex Cable FC-CFBM6DF-CBAF-M003 Feedback Cable, 28-Pin to Flying Leads, 3m Long

　　Flex-Cable FC-FPBM6DF-16AF-M003 Motor Power Cable w/ Brake Flying Lead

　　New In Box Pentair SF0524414 Filter Fan, Power: 24VDC 0.17A, Speed: 3050RPM