In modern industrial automation systems, reliable communication between human-machine interface (HMI) and programmable logic controller (PLC) is the core to achieve process monitoring and control. Mitsubishi Heavy Industries, Ltd.'s DIASYS Nettation system, as a high-performance process control platform, is often used in conjunction with the Pro face series human-machine interface. This article is aimed at on-site engineers and system integrators, detailing the complete process of establishing communication between Pro face and DIASYS Netmation through MODBUS TCP protocol, including system topology selection, parameter configuration, address mapping, redundant CPU processing, and common error troubleshooting, to help you quickly complete project deployment and solve communication failures during operation.
System configuration and network topology selection
The Pro face human-machine interface and Netmation CPU support multiple network connection methods to meet the needs of control systems of different scales. Before starting the configuration, it is necessary to select a suitable topology based on the actual structure on site. All connections are based on Ethernet (TCP/IP), and the Netmation system follows the MODBUS TCP specification, so this driver does not support GP-4100 series monochrome models.
1.1 Connection method for single CPU system
When there is only one Netmation CPU in the system, the following topology can be used:
1: 1 Connection: A Pro face is directly connected to a Netmation CPU. This is the simplest structure, suitable for single machine equipment or small sections.
1: N-connection: One Pro face communicates with multiple Netmation CPUs simultaneously. For example, a central monitoring station needs to read data from multiple decentralized controllers.
n: 1 Connection: Multiple Pro faces access the same Netmation CPU. Commonly used for multiple operator stations to monitor the same large-scale process.
n: M-connection: Multiple Pro faces and multiple Netmation CPUs form a mesh communication. Suitable for complex production lines with multiple control areas and independent operation stations in each area.
1.2 Connection method of dual redundant CPU system
The Netmation system supports CPU redundancy configuration to improve availability. In a dual CPU architecture, the primary CPU and secondary CPU run synchronously, and in the event of a primary CPU failure, the secondary CPU automatically takes over. The Pro face driver has specifically designed a control mode detection mechanism for this purpose.
1: 1 Connection: Connect one Pro face to a pair of redundant CPUs. By configuring the 'Control State Storage Address', Pro face can detect which CPU is in the master control state every second and automatically switch communication targets.
1: N-connection: One Pro face connects multiple pairs of redundant CPUs. IP addresses and control mode detection addresses need to be specified separately for each pair of CPU's primary and backup instances in the device settings.
n: 1/n: m hybrid connection: suitable for scenarios with multiple HMIs and multiple pairs of redundant CPUs. Reasonable planning of communication load and redundant switching logic for each HMI is required in the project.
Engineering suggestion: Regardless of the topology used, IP address conflicts should be avoided, and the IP addresses of all Ethernet nodes (including Pro face, Netmation CPU, switches, etc.) must be in the same subnet and unique. When connecting a dual redundant system, it is necessary to configure the control state storage address (such as CDO0001) in the Netmation dedicated software, otherwise Pro face will not be able to correctly recognize the current active CPU.
External device selection and driver configuration
In the Pro face programming software GP Pro EX, it is necessary to correctly select the external device type to enable the corresponding communication protocol.
2.1 Equipment selection steps
Open the GP Pro EX project and enter the 'System Settings' window.
Click on 'Device/PLC Settings' to add a new device to the device list.
Select 'Mitsubishi Heavy Industries' from the' Manufacturer 'dropdown menu.
Select 'DIASYS Netmation MODBUS TCP' from the 'Driver' dropdown menu.
2.2 System Area Usage Options
This driver provides a 'Use System Area' option. After activation, the Pro face system data area (LS area) will synchronize with the specified device address in Netmation. With this feature, engineers can switch HMI display screens, pop up alarm windows, or write values by modifying specific addresses in Netmation's ladder diagram program, achieving deep integration of HMI and PLC control logic. The specific setting method of the system area can refer to the "LS Area (Direct Access Mode Area)" chapter in the GP Pro EX reference manual.
2.3 Port selection
Some models of Pro face offer multiple Ethernet interfaces. Please specify the actual port connected to Netmation (such as LAN1, LAN2) in the settings. This setting can also be modified in HMI offline mode.