Mitsubishi Electric Implementation

Modbus TCP/IP for Mitsubishi Electric

Ethernet-based variant of Modbus using TCP/IP. Combines simplicity of Modbus with speed and scalability of Ethernet.

Type: Industrial EthernetSpeed: 10/100/1000 MbpsReleased: 1999Organization: Modbus Organization

1 Gbps capable

Bandwidth

Unlimited (network dependent)

Max Nodes

100m per segment (with switches: unlimited)

Max Distance

Real-Time

Protocol Overview

Mitsubishi FX5U/Q-series support Modbus TCP through built-in Ethernet ports. GX Works3 provides MODBUS_TCP_Client and MODBUS_TCP_Server function blocks with intuitive configuration.

When to Use Modbus TCP/IP

Choose Modbus TCP/IP for SCADA systems, plant-wide networks, remote monitoring, or when integrating industrial equipment with IT systems.

Mitsubishi Electric Hardware Requirements

Compatible Communication Modules

FX5U-xMy/ES built-in Ethernet

QJ71E71-100 (Q-series Ethernet)

RJ71EN71 (redundant Ethernet)

FX5-ENET (Ethernet adapter)

Wiring Details

Network Setup

Configure IP in GX Works3 Network Settings. Port 502 standard. Supports 100/1000Mbps auto-negotiation.

Mitsubishi Electric Software & Programming

Function Blocks & Instructions

MODBUS_TCP_Client

MODBUS_TCP_Server

SOCKET_Send/Recv (low-level)

ModbusTCP_Master_Multi (multiple slaves)

Mitsubishi Electric Code Example

MODBUS_TCP_Client(
  Enable := M100,
  Command := 3,  // FC03
  IPAddress := '192.168.1.10',
  Port := 502,
  UnitID := 1,
  StartAddr := 0,
  NumRegs := 10,
  DataAddr := D100,
  => Done := M102,
  => Error := M103
);

Mitsubishi Electric-Specific Implementation Notes

String-based IP address configuration. Error codes: 2001H = connection failed, 2002H = timeout, 2003H = data error. FX5U supports up to 8 simultaneous TCP connections. Response time typically 5-15ms on Gigabit Ethernet.

Technical Specifications

Physical Layer

Physical Layer: IEEE 802.3 Ethernet
Cable Type: Cat5e/Cat6 Ethernet
Topology: Star, Tree, Ring
Power Over Cable: No

Data Layer

Data Link: TCP/IP
Encoding: Binary
Error Detection: TCP checksum
Frame Size: 1500 bytes (MTU)

Performance

Scan Time: 1-10ms typical
Deterministic: No
Real-Time: No

Certification

Certification Required: No
License Cost: Free (open standard)
Version: Current

Advantages & Disadvantages

Advantages

✓High speed (up to 1 Gbps)
✓Uses standard Ethernet infrastructure
✓Unlimited nodes and distance (with switches)
✓Easy IT integration
✓Simple protocol (Modbus heritage)
✓Open standard and free
✓Remote access capability

Disadvantages

✗Not deterministic (not real-time)
✗No built-in security (requires VPN/firewall)
✗Higher latency than dedicated fieldbuses
✗Requires managed switches for large networks
✗No device profiles or configuration tools

Common Use Cases & Applications

SCADA systems

Plant-wide data collection

Building management systems

Remote monitoring

Enterprise system integration

Large distributed systems

Industry Adoption

Adoption LevelVery High

Market Share25-35% of industrial Ethernet

Geographic PresenceWorldwide

Primary Industries

Oil & GasWater/WastewaterBuilding AutomationManufacturingEnergy

Supported Message Types

Read Coils

Read Discrete Inputs

Read Holding Registers

Write Single Coil

Write Single Register

Write Multiple Registers

Supported PLC Brands

Siemens Allen-Bradley Mitsubishi Schneider Electric Beckhoff ABB Rockwell

Phoenix Contact

Wago

Protocol Comparisons

Modbus TCP/IP vs EtherNet/IP

Modbus TCP is simpler and open; EtherNet/IP offers better diagnostics and CIP ecosystem

View Detailed Comparison →

Quick Links

Alternative Protocols

Related Standards

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