Modbus & Industrial Automation
PLC Commissioning Checklist for Modbus Communication
Published September 21, 2026
A reusable checklist for testing Modbus communication between PLCs, HMIs, meters and controllers.
A repeatable checklist prevents simple configuration errors from consuming commissioning time.
Connection
- Confirm RTU or TCP
- Verify serial parameters or IP/port
- Check wiring and network reachability
Protocol
- Confirm slave/unit identifier
- Confirm function code
- Confirm register address and quantity
Data
- Confirm 16-bit or 32-bit representation
- Check byte and word order
- Confirm engineering units and scaling
Verification
- Start with Read Once
- Inspect HEX TX/RX when needed
- Enable polling after a known-good request works
- Log important values to CSV during extended tests