Modbus workbench

Modbus RTU / TCP Debugger

Builder

Frame builder

Common PDU fields Used by both RTU and TCP

Slave ID Function Start address Length / quantity Write values

Modbus RTU Adds CRC16 automatically, for serial RTU

RTU frame

Modbus TCP Uses a transaction ID and MBAP header

Transaction ID TCP frame

Parser

Response parser

Response frame

Web Serial

Serial port

Disconnected

Baud rate Data bits Stop bits Parity

Command queue

Frame type Station Function Address Quantity Write values Transaction ID

Timed command Interval ms Timer off

Communication log

Local processing

Checking Web Serial…

Frame generation, CRC checks, MBAP assembly, PDU parsing and response parsing all run locally in this browser. Serial data only passes through the local port you authorize and is never uploaded.