ModBus

Modbus, published by Modicon in 1979, is a serial communications protocol widely used with programmable logic controllers (PLCs). Modbus has become a standard in the industry, known for its simplicity and robustness, serving as one of the most commonly used protocols for connecting industrial electronic devices. It finds extensive application in electronic control systems, enabling seamless communication among various industrial devices and components. The protocol"s reliability and efficiency contribute significantly to the integration and coordination of electronic control systems in industrial settings.

Logic Analyzer

TB3016B

TB3000 series Specifications PDF

MSO2116B (w/ analog channels)

MSO2000 series Specifications PDF

Modbus Decode

Protocol Quick Setup:

1. Click Quick Settings to select a protocol for logic analyzer capture.

2. Select ModBus for decoding.

3. The system provides recommended settings for trigger type, sampling rate, voltage threshold, and channel settings.

4. Click the icon to access the Decode Settings screen.

Decode Settings

Channel: Modbus (Tx) or Modbus (Rx).

Transmission Mode: ASCII and RTU mode.

Auto: Auto detection idle polarity.

Idle high: Idle condition shows High.

Idle low: Idle condition shows Low.

Auto Detect: Set the Baud Rate manually if not selected.

Baud Rate: Data rate (bits per second), and the range is 110 ~ 2M (bps).

Parity: N-None Parity, O-Odd Parity, E-Even Parity.

MSB First: The default is LSB first; click it to change to MSB first.

Show scale in the waveform: Display the waveforms with scales.

ModBus Decoding Examples