@cvdd https://github.com/UniPiTechnology/neuron_tcp_modbus_overlay is only for Neurons and will not work for the UniPi 1. For UniPi 1 there is only Evok as API from us. But if you need Modbus and do not want to use the HTTP REST api, websocket or JSON RPC, then take a look at someone implementing Modbus for UniPi 1