#Modbus protocol
45 articles tagged with #Modbus protocol. This page is set to noindex per SEO configuration.
Modbus TCP Beckhoff TwinCAT: Client and Server Setup
Modbus TCP Beckhoff TwinCAT configuration with TF6250: client function blocks, server XML mapping, licensing by TwinCAT version, and the usual failure points.
Modbus TCP CODESYS: Step-by-Step Configuration
Modbus TCP CODESYS configuration for WAGO, Phoenix Contact, ABB, and Delta PLCs: master and slave setup, channel configuration, and vendor-specific notes.
Modbus TCP ControlLogix Setup in Studio 5000
Modbus TCP ControlLogix setup three ways: the ProSoft MVI56E-MNETC module, AOI socket messaging, and a gateway, with pitfalls and performance notes for each.
Modbus to MQTT: How the Gateway Bridge Works
Modbus to MQTT explained: how a gateway maps registers to topics, builds JSON payloads, and handles reads, writes, QoS and TLS. With a worked example.
Modbus Parity and Character Format
Modbus parity and character format: data bits, parity, and stop bits for RTU and ASCII, the even-parity default, the two-stop-bit rule, and what parity misses.
Modbus Unit Identifier Explained: Unit ID by Scenario
Modbus Unit Identifier (Unit ID) explained by scenario: direct TCP devices, RTU gateways, multi-port gateways. Value ranges, common defaults, troubleshooting.
Modbus Broadcast Function Codes: Address 0 Explained
Modbus broadcast on address 0: which function codes support it, how serial and TCP differ, turnaround timing, gateway behavior, and when to actually use it.
Modbus Client-Server vs Master-Slave Terminology
Modbus client-server vs master-slave: the 2020 terminology change explained. What stays the same, translation table, and how to read mixed-terminology docs.
Modbus TCP MBAP Header Explained: 7 Bytes Byte by Byte
Modbus TCP MBAP header decoded byte by byte: Transaction ID, Protocol ID, Length, and Unit ID, with a real hex dump, network byte order, and common mistakes.
Modbus TCP Security Explained: TLS on Port 802
Modbus TCP Security explained: TLS on port 802, X.509 certificates, role-based access control, deployment alongside port 502, cipher suites, real setup.
Modbus Byte Order and Word Order: Fix Your 32-Bit Values
Modbus byte order and word order decoded: ABCD, CDAB, BADC, and DCBA. Fix reversed floats and byte-swapped longs, with a five-minute test and vendor defaults.
Modbus TCP S7-1500: MB_CLIENT and MB_SERVER Setup
Modbus TCP S7-1500 setup in TIA Portal: MB_CLIENT, MB_SERVER, and TCON_IP_v4 configured, MB_MODE mapped to function codes, and status codes 8200 and 809B fixed.
Modbus TCP Mitsubishi iQ-R: GX Works3 Setup Guide
Modbus TCP Mitsubishi iQ-R setup in GX Works3: RJ71EN71 module parameters, MODBUS Device Assignment, float byte order, exception codes, and troubleshooting.
Modbus TCP Schneider M340: Unity Pro Setup Guide
Modbus TCP Schneider M340 configuration: CPU embedded port, NOE 0100 and NOC 0401 modules, server and client roles, READ_VAR, WRITE_VAR, and ADDM explained.
Modbus Exception Codes Explained: Complete Reference
Modbus exception codes 01 through 0B in full: Illegal Function, Illegal Data Address, Slave Device Failure, and gateway errors, each with the fix that works.
Top 10 Free Modbus Simulators
Top 10 free Modbus simulators for RTU and TCP testing — slave and master tools with setup steps, command-line examples, and download links.
Wireshark Modbus RTU: Decode Serial RS-485 Traffic
Wireshark Modbus RTU over RS-485: COM port setup with a serial adapter, DLT 147 configuration, display filters, and how to read framing and CRC errors.
Modbus TCP CompactLogix Setup in Studio 5000
Modbus TCP CompactLogix setup with Rockwell's free AOI in Studio 5000: client and server roles, AOI parameters, polling multiple devices, and gateway options.