In order to launch the Modbus communication properly, it is necessary to follow these steps:
Step 1: Having the device added correctly in the iC Tool, expand the Networks container, and go to the Modbus component.
Step 2: The Interfaces component with the Serial and Ethernet components are added by default. Go to the Serial component to configure the RS485 port for Modbus RTU client communication. Go to the Ethernet component to configure the IP port for Modbus TCP/IP communication.
Step 3: The RAC18-IP controller allows to communicate as the Modbus RTU client device and Modbus TCP/IP client or server device.
(a): The RAC18-IP component (LocalDevice) for Modbus TCP/IP server device is also added by default. In order to configure the Modbus server device, go the the component.
Worth to Notice:
The RAC18-IP component (LocalDevice) has a Modbus gateway extension, which allows Modbus RTU server devices (for example, RS485 I/O modules) to communicate with the Modbus TCP/IP network through a gateway device (for example, a RAC18-IP).
(b): In order configure the Modbus RTU or TCP/IP network, the Network and Device components need to be added, along with AnalogPoint, BinaryPoint, and StringPoint components, as necessary. Go to the Device Libraries and expand the Core library for the Network component and Modbus library for other components. Choose components to be added—components may be added one by one or grouped in one selection. Drag the selected component(s) and drop it(them) under the Modbus component in the Networks container.
Worth to Notice:
Please remember that the components' hierarchy needs to be preserved here: the Network component has to be located under the Modbus component, the Device component under the Network component, and the AnalogPoint/BinaryPoint/StringPoint components have to be placed under the Device component.
If the superior component is selected in the Workspace Tree window and its special view (Network Manager/Device Manager/Point Manager) is opened in the main screen, the Device Libraries shows only the components that can be added directly under it. For example, if the Modbus component is selected in the Workspace Tree window, the Device Libraries shows only the Network component in the Core library.
Step 5: Go to each added component, open its Property Sheet (or go the the Modbus component's Property Sheet and expand each component there), and set their parameters (enable, addresses, etc.). Make sure to save the changes.
Ready to Use: Configured components are ready for proper Modbus communication.