The Human Machine Interface (HMI) and Programmable Logic Controller (PLC) are pre-programmed and the interface of Digi One IAP’s Ethernet is organized. You have an available system with a single-port slave and serial master; such as a low-end PLC and local HMI. The Digi One IAP permits you to retrofit this program so the serial master can distribute this slave with the world.
The HMI linked to the port of screw terminal and the PLC to the port of DB-9. This can be opposite, depending on your requirements. The order doesn’t matter but you necessary to adjust the steps as appropriate. This local HMI or panel of operator on port 1 and a single-port PLC on port 2 when pass-thru is enabled:
• Port 1 is the terminal screw and can be EIA-485,232, or 422.
• Port 2 is EIA-232 and is the DB-9 only.
Theory of Operations
The Digi One IAP maintains this program because it is Modbus protocol-aware. It understands Modbus/TCP, Modbus/RTU, and Modbus/ASCII responses and requests. Offered this thoughtful of the protocol of Modbus, the Digi One IAP works like a “network print server”; it can fit in & interrupt needs from many masters to many slaves. Demands from the HMI are implicit to be predetermined for the PLC. The similar is true requests from network-enabled PLC, remote OPC, or programming software.
Link your devices
The Programmable Logic Controller (PLC) and Human Machine Interface (HMI) can be linked to either physical serial interface. This article supposes that the HMI is on the PLC is connected via the ‘DB-9’ connector and the ‘screw terminal’ block. If you tie in the opposite order, you just require to update the steps.
Arrange the firmware in the Digi One IAP
You have two choices for configuring the Digi One IAP. You can utilize your web browser to contact a Web Wizard, or you can use HyperTerminal to access the Digi One IAP by port of TCP 23.