Do-More 模擬器透過 Modbus TCP 與 Node-RED 整合

在 Do-more Designer 中設定 Modbus 伺服器

開啟 Do-more Designer 專案，前往 Project -> System Configuration -> Ethernet Ports。 
勾選 Modbus TCP Server，並確認監聽連接埠（Default Port）為 502。 [1]
確保你的 PLC 內部資料（例如 D 暫存器或 C 記憶位元）有對應對齊到 Modbus 的記憶體區塊。Do-more 內建對應的 Modbus 區域包含：
• MHR (Modbus Holding Registers, 功能碼 FC03 / FC06 / FC16)
• MC (Modbus Coils, 功能碼 FC01 / FC05 / FC15)
• MIR (Modbus Input Registers, 功能碼 FC04)
• MI (Modbus Inputs, 功能碼 FC02) 

在 Node-RED 中設定 Modbus 節點

在 Node-RED 內安裝 node-red-contrib-modbus 擴充套件。 
拖曳 Modbus Read 或 Modbus Flex Getter 節點至畫布中。 
雙擊節點設定 Server 參數（點擊鉛筆圖示新增 Modbus TCP 連線）：
• Type: Modbus TCP
• Host: 輸入你的 Do-more PLC 的 IP 位址
• Port: 502
• Unit-ID: 通常設為 1 (或對應 PLC 設定) [1, 2]
在讀取節點中設定對應的 FC（功能碼，例如 FC3 讀取保持暫存器 MHR）與 Address / Quantity 進行數據擷取。  

 

將 AutomationDirect Do-more PLC (透過 Do-more Designer 軟體設定) 的資料透過 Modbus TCP 輸出給 Node-RED 的 node-red-contrib-modbus 節點，最簡單的做法是將 Do-more 設定為 Modbus TCP 伺服器 (Server/Slave)，而 Node-RED 作為客戶端 (Client/Master) 來主動輪詢 (Poll) 資料。

1-Based 與 0-Based 的位址位移 (Offset)

• Do-more 內部與某些傳統 PLC 說明書會使用 1-based 定址（例如將 MHR0 稱為 40001）。
• Node-RED 預設使用 0-based 定址。因此在 Node-RED 的 Address 欄位中，請直接輸入 0 來代表第一個暫存器，不需要加上 40001。
• 如果發現讀出來的資料錯位了一個位置（例如讀 MHR1 卻讀到 MHR0），請嘗試將 Node-RED 的 Address 加 1 或減 1。

node-red程式

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