SUNSPEC protocol over MODBUS TCP - PV Plant sensors - SCADA in ...I have a project...what hardware do I need? Posted November 28, 2018 · Report reply 3 hours ago, Joe Tauser said: Any of the Unitronics Vision or UniStream PLCs can be a blank slate capable of both Modbus RTU and Modbus TCP communication in both Master and Slave mode at the same time. Whether a unit is a server or client depends on the point of view of data flow, but generally the "Server" is the slave and the "Client" is the master. Your requests #1 and #5 are kind of ambiguous and need more details. As to what hardware you need, I would lean toward the UniStream family as it has much more powerful networking capabilities and the Modbus is easier on it. All you have to decide is how big the display needs to be and a list of I/O connected to it. Joe T. Hello and thanks for the support. #1 SCADA communication with the grid operator might be stand alone to the inverters from this system (machine to machine sim card operated already provided from grid operator). They are going to provide the values of power factor , power limitation , power offset etc.. this values we have to pass to inverters through modbus RTU over RS485. (for control). I'm waiting from inverters provider to confirm that, but the idea would be like that. What you recommend for that ? #5 Ability to export on third party energy management portal - can be done in 2 basic ways. 1. send CSV file to FTP and the platform will do the handling to the database 2. have another one modbus TCP "Server" available (for the third party portal) with all the values available !! In that case, how we are going to pass values from one modbus TCP Server to another? What if we have irradiation sensor sitting on the MODBUS RTU site somewhere in the field, and this value must be passed to everyone !! grid operator, inverter portal through SUNSPEC and third party portal. This is as complicated might be. nothing more.