Having issues with the wired internet connectivity of your APsystems ECU-R gateway? The problem might be with the choice of RJ45 port connected to your broadband modem.
APsystems ECU-R is the communications gateway for APsystems inverters. It collects and transfers module performance data to the cloud-based Energy Monitoring & Analysis software (EMA), and accessible by web-based devices.
The ECU-R’s internet connection can be made to a broadband modem with either a CAT5 ethernet cable or the built-in 802.11g/n Wi-Fi. When using CAT5 cable, the correct RJ45 port must be used or the ECU-R unit will not be able to access the internet.
There are two RJ45 ports on the back of the ECU-R. One is a 10/100 ethernet port labeled “RJ45-Internet” used for internet access. The other port is unlabeled, and not used in North American.
The unlabeled RJ45 port is designed for Demand Response Mode 0 (DRM0), which allows utilities to disconnect inverters from the grid, and only used in Australia. If an Ethernet cable intended for internet access is inserted in the unlabeled port, the unit will not be able to access the internet.
Installers should be sure to connect the Ethernet cable into the correct port, labeled “RJ45-Internet”. If connectivity issues persist, APsystems technical support can be reached at:
If you have any questions about these products, you are welcome to call us at 855-755-5855 or email the Renvu team at