Issue
Clarification on whether four Modbus licenses are needed to support all four RS-485 ports on a Niagara R2 UNC-520.
Product Line
TAC IA SeriesEnvironment
Niagara R2 UNC-520
Cause
Site requires integration with four different vendor products using Modbus RTU over RS-485, leading to confusion about licensing requirements for multiple ports.
Resolution
A UNC-520 supports up to four separate Modbus Async Networks, each using a distinct ModbusAsyncService.
Only one Modbus driver license is required per UNC, regardless of the number of RS-485 ports used.
Only one Modbus driver license is required per UNC, regardless of the number of RS-485 ports used.
