This section provides a collection of procedures to be used for the iSMA-B-FCU Modbus drivers in order to build networks of devices with Modbus points. The iSMA-B-FCU device has two RS485 ports. The COM2 port (with RJ12 connector) can be used as a Modbus RTU/ASCII master. There is no software limit of devices connected to the Modbus Async bus, but the total number of all Modbus points cannot exceed 200.