Modbus is a request/reply protocol that has one Modbus client in its network and may have many Modbus servers. Servers can control only their own internal states and clients can read and write data in them. Modbus is not restricted by the network type, in theory it can use any QIODevice . However, not every plugin supports all classes derived from QIODevice .
每個 Modbus 服務器擁有可以在其中存儲數據的 4 個錶。
| 名稱 | 一字段數據範圍 | 客戶端權限 |
|---|---|---|
| 離散輸入 | 0-1 | 讀取 |
| 綫圈 | 0-1 | 讀/寫 |
| 輸入寄存器 | 0-65535 (0xffff) | 讀取 |
| 保持寄存器 | 0-65535 (0xffff) | 讀/寫 |
Modbus API 提供瞭訪問 Modbus 設備的一些公共 API：
