Modbus協(xié)議常被用在工業(yè)現(xiàn)場，用于各類設(shè)備的數(shù)據(jù)采集以及遠程控制，Node-RED社區(qū)有很多開發(fā)者為Modbus協(xié)議提供了各種類型的Modbus節(jié)點，有用于邊緣采集的“node-red-node-arc-modbus” ，也有通用Modbus協(xié)議?！?/span>node-red-contrib-modbus”，接下來就通過使用Modbus協(xié)議棧演示Modbus IO設(shè)備接入Node-RED網(wǎng)關(guān)。
與以往添加節(jié)點的方式一樣，先選擇菜單，進入“節(jié)點管理”，輸入節(jié)點名稱“node-red-contrib-modbus”，帶搜索完成后選擇對應(yīng)的節(jié)點，點擊安裝，帶安裝完成后會出現(xiàn)一系列的Modbus操作節(jié)點。
本片文章主要對靜態(tài)操作節(jié)點“Modbus-Read”、“Modbus-Write”、“Modbus-Response”，以及動態(tài)操作節(jié)點“Modbus-Flex-Connector”、“Modbus-Flex-Getter”、“Modbus-Flex-Write”進行說明，利用上述節(jié)點即可實現(xiàn)遠程IO數(shù)據(jù)的采集和控制。
“Modbus-Read”，網(wǎng)關(guān)作為主機，配置靜態(tài)連接參數(shù)以及靜態(tài)Modbus參數(shù)，通過網(wǎng)絡(luò)、串口，以及配置的協(xié)議（Modbus RTU與Modbus TCP）去讀取指定Modbus從機的指定寄存器數(shù)據(jù)。
“Modbus-Write”，網(wǎng)關(guān)作為主機，配置靜態(tài)連接參數(shù)以及靜態(tài)Modbus參數(shù)，通過網(wǎng)絡(luò)、串口，以及配置的協(xié)議（Modbus RTU與Modbus TCP）與傳入的參數(shù)配置指定Modbus從機的指定寄存器數(shù)據(jù)。
“Modbus-Read”與“Modbus-Write”在使用前都需要提前配置網(wǎng)關(guān)如何連接設(shè)備，左圖說明通過串口查詢的配置，右圖說明通過網(wǎng)絡(luò)查詢的配置；
“Modbus-Read”節(jié)點需要配置設(shè)備的地址（Unit-id）,我這里配置為104，也可以不輸入，若不輸入則采用連接時配置的默認設(shè)備地址，還需要配置采用的功能碼，我這通過讀取AO的整型值為例（查詢IO設(shè)備的寄存器表可以得到AO存放在40100-40103），所以FC（功能碼）配置為3（讀取保持寄存器），如果讀取AI該配置FC為4（讀取輸入寄存器，查詢IO設(shè)備的寄存器表可以得到AO存放在30100-30103），在配置節(jié)點的地址為100，寄存器數(shù)量為4，自動輪詢?yōu)?/span>10s（可根據(jù)自己需要調(diào)整時基為毫秒、秒、分、時），選擇上一步配置的連接參數(shù)。
“Modbus-Write”和“Read”都具有地址、寄存器地址、數(shù)量、連接服務(wù)器，相同的參數(shù)配置方法相同不在單獨說明，寫入節(jié)點還需要傳入數(shù)據(jù)，如右圖，傳入4個寄存器參數(shù)。
“Modbus-Response”用于輸出前端Modbus節(jié)點的返回數(shù)據(jù)在Node-RED控制臺顯示的節(jié)點，一般不使用。
“Modbus-Flex-Connector”用于與Modbus設(shè)備動態(tài)建立連接的節(jié)點，使用該節(jié)點需要傳入連接所需的參數(shù)，以及配置存儲連接信息的空間（配置一個新的服務(wù)器節(jié)點，IP和端口可以任意配置，其余參數(shù)根據(jù)實際需求調(diào)整，這里采用TCP連接并通過Modbus TCP協(xié)議通信，超時時間為1000），其余參數(shù)可通過前端節(jié)點傳入。
添加“inject”節(jié)點，添加“payload”對象，輸入JSON數(shù)據(jù){"connectorType":"TCP","tcpHost":"192.168.88.35","tcpPort":502}，點擊部署，可通過手動觸發(fā)連接；
連接成功后調(diào)試日志接口輸出一下數(shù)據(jù)；
“Modbus-Flex-Getter”用于動態(tài)查詢IO設(shè)備參數(shù)，需要傳入設(shè)備地址、功能碼、首地址寄存器、寄存器數(shù)量，目前該控件支持01、02、03、04功能碼，動態(tài)連接一樣，在節(jié)點前端添加一個“inject”傳入Modbus請求參數(shù)；
“Modbus-Flex-Write”用于動態(tài)寫入IO設(shè)備數(shù)據(jù)，需要傳入設(shè)備地址、功能碼、首地址寄存器、寄存器數(shù)量、操作數(shù)據(jù)，目前該控件支持單個操作的05與06也支持連續(xù)操作的15、16功能碼，與其他動態(tài)連接的節(jié)點一樣，在節(jié)點前端添加一個“inject”傳入Modbus請求參數(shù)和數(shù)據(jù)；
下面為節(jié)點配置，可通過Node-RED導(dǎo)入功能復(fù)制本文案例；
動態(tài)連接參數(shù)輸入：
[{"id":"e45d6bd45793ccad","type":"modbus-flex-connector","z":"5d4fa2aa0a8f4fcf","name":"","maxReconnectsPerMinute":4,"emptyQueue":false,"showStatusActivities":false,"showErrors":false,"server":"904086e697ba6c29","x":370,"y":620,"wires":[["b4159f0075e37cfc"]]},{"id":"902892a0233fc0e2","type":"inject","z":"5d4fa2aa0a8f4fcf","name":"連接參數(shù)輸入","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{"connectorType":"TCP","tcpHost":"192.168.88.35","tcpPort":502}","payloadType":"json","x":110,"y":620,"wires":[["e45d6bd45793ccad"]]},{"id":"904086e697ba6c29","type":"modbus-client","name":"測試設(shè)備","clienttype":"tcp","bufferCommands":true,"stateLogEnabled":false,"queueLogEnabled":false,"failureLogEnabled":true,"tcpHost":"192.168.88.105","tcpPort":"502","tcpType":"DEFAULT","serialPort":"/dev/ttyUSB","serialType":"RTU BUFFERD","serialBaudrate":"9600","serialDatabits":"8","serialStopbits":"1","serialParity" :"none","serialConnectionDelay":"100","serialAsciiResponseStartDelimiter":"0x3A","unit_id":"1","commandDelay":"1","clientTimeout":"1000","reconnectOnTimeout":true,"reconnectTimeout":"2000","parallelUnitIdsAllowed":true,"showWarnings":true,"showLogs":true}]
動態(tài)查詢參數(shù)：
[{"id":"bb9ead56ab51483e","type":"modbus-flex-getter","z":"5d4fa2aa0a8f4fcf","name":"" , "showStatusActivities":false,"showErrors":false,"showWarnings":true,"logIOActivities":false,"server":"904086e697ba6c29","useIOFile":false,"ioFile":"","useIOForPayload":false,"emptyMsgOnFail":false,"keepMsgProperties":false,"delayOnStart":false,"startDelayTime":"","x":350,"y":720,"wires":[[],["a051c717d9537768"]]},{"id":"181a3bf2d08b472d","type":"inject","z":"5d4fa2aa0a8f4fcf" ,"name" : "動態(tài)查詢AO狀態(tài)","props":[{"p":"payload.fc","v":"3","vt":"num"},{"p":"payload.unitid","v":"105","vt":"str"},{"p":"payload.address" , "v":"100","vt":"str"} , {"p":"payload.quantity","v":"4","vt":"str"}],"repeat":"","crontab":"","once": false ,"onceDelay" : 0.1,"topic":"","x":120,"y":720,"wires":[["bb9ead56ab51483e"]]},{"id":"904086e697ba6c29" , "type":"modbus-client" , "name" ： "測試設(shè)備" ，"clienttype"："tcp","bufferCommands" : true," stateLogEnabled":false , "queueLogEnabled" : false,"failureLogEnabled":true,"tcpHost":"192.168.88.105" , "tcpPort":"502","tcpType":"DEFAULT","serialPort":"/dev/ttyUSB","serialType":"RTU-BUFFERD" , "serialBaudrate" : "9600","serialDatabits" : "8","serialStopbits" : "1" , "serialParity":"none" ,"serialConnectionDelay":"100","serialAsciiResponseStartDelimiter" : "0x3A" , "unit_id":"1","commandDelay" :"1","clientTimeout":"1000","reconnectOnTimeout":true,"reconnectTimeout":"2000","parallelUnitIdsAllowed":true,"showWarnings":true,"showLogs":true}]
動態(tài)修改寄存器：
[{"id":"2d5ea26349786e57","type":"modbus-flex-write" , "z" : "5d4fa2aa0a8f4fcf" , "name" : "","showStatusActivities":false,"showErrors":false,"showWarnings":true,"server":"904086e697ba6c29","emptyMsgOnFail":false,"keepMsgProperties":false,"delayOnStart":false,"startDelayTime":"","x":350,"y":780,"wires":[[],["a051c717d9537768"]]},{"id":"00d9fdbe7e55a434","type":"inject","z":"5d4fa2aa0a8f4fcf","name":"動態(tài)寫入AO","props":[{"p":"payload.value","v":"[20000,20000,20000,20000]","vt":"json"},{"p":"payload.fc" ,"v":"16","vt":"num"},{"p":"payload.unitid","v":"105","vt":"str"},{"p":"payload.address" , "v":"100","vt":"str"},{"p":"payload.quantity","v":"4","vt":"str"}],"repeat" :"","crontab" :"","once":false,"onceDelay" :0.1,"topic" :"","x":110,"y":780,"wires":[["2d5ea26349786e57"]]},{"id":"904086e697ba6c29","type":"modbus-client" ,"name" :"測試設(shè)備" , "clienttype" : "tcp","bufferCommands" : true,"stateLogEnabled" : false," queueLogEnabled": false,"failureLogEnabled" : true,"tcpHost" : "192.168.88.105" , "tcpPort" :"502","tcpType":"DEFAULT","serialPort":"/dev/ttyUSB","serialType":"RTU-BUFFERD" , "serialBaudrate" :"9600","serialDatabits":"8","serialStopbits":"1","serialParity":"none","serialConnectionDelay":"100","serialAsciiResponseStartDelimiter":"0x3A","unit_id":"1","commandDelay":"1","clientTimeout":"1000","reconnectOnTimeout":true,"reconnectTimeout":"2000","parallelUnitIdsAllowed":true,"showWarnings":true,"showLogs":true}]
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