Modbus Nodes
Modbus is the most widely deployed protocol in industrial automation. MaestroHub supports all three variants: TCP, RTU, and ASCII so you can communicate with PLCs, sensors, meters, and supervisory systems from a single node set.
Configuration Quick Reference
| Field | What you choose | Details |
|---|---|---|
| Parameters | Connection, Function, Function Parameters optional Timeout Override, Debug Mode | Choose the shared Modbus connection profile (credentials, transport method, retry settings) and its saved function, then fill in the parameters specified within the function. Inputs accept literal values or Maestro expressions that are validated at save time and resolved during each execution. |
| Settings | Retry on Fail, On Error, Notes, Display Note In Pipeline | Configure pipeline-level behavior: retry strategy, whether errors stop or continue, and operator notes that can surface on the canvas for quick context. |
Parameters inherit validation from the stored function, while node-level settings apply Maestro pipeline controls such as retries and inline documentation.
Modbus Read Node
Modbus Read Node
Read data from PLCs, sensors, meters, and industrial devices.
Supported Function Types:
| Function Name | Purpose | Common Use Cases |
|---|---|---|
| Read Coils (0x01) | Read digital outputs | Motor status, valve positions |
| Read Discrete Inputs (0x02) | Read digital inputs | Limit switches, sensors |
| Read Holding Registers (0x03) | Read holding registers | Setpoints, configuration |
| Read Input Registers (0x04) | Read input registers | Temperature, pressure, flow |
| Read FIFO Queue (0x18) | Read FIFO queue | Event logs, alarm history |
Modbus Write Node
Modbus Write Node
Write control values, setpoints, and configuration to devices.
Supported Function Types:
| Function Name | Purpose | Common Use Cases |
|---|---|---|
| Write Single Coil (0x05) | Write single digital output | Start/stop motor |
| Write Single Register (0x06) | Write single register | Update setpoint |
| Write Multiple Coils (0x0F) | Write multiple digital outputs | Batch control |
| Write Multiple Registers (0x10) | Write multiple registers | Configuration update |
| Write Masked Register (0x16) | Masked register write | Bit manipulation |
| Read/Write Multiple Registers (0x17) | Atomic read+write | Synchronized operations |
Safety First
Always implement validation and safety checks before writing to industrial equipment. Consider adding condition nodes to verify values are within safe ranges.