The NI monitoring devices can read data using Modbus TCP or serial communication. Modbus data will be included in the trend points stored on the server and can be used in collection triggers and alarms.
Serial communication—The device can address one or more Modbus slaves and the Modbus slaves can communicate directly with the device.
Ethernet communication—The device establishes a TCP connection with a Modbus slave on a specific IP address and port. The device can support TCP connections to multiple Modbus slaves.
OPC UA Communication
The device acts as an OPC UA (Open Platform Communications Unified Architecture) client and initiates queries from the OPC UA Server. The device establishes a connection with the specific URL of the OPC UA Server. The device typically connects through TCP.