WPC-D Solar PV String Level Monitoring Device monitors current and voltage at the string level inside a combiner box This device iscompatible with PV string voltages up to 1500VDC. It canmonitor 8, 12, 16,20, and 24 strings and measure up to 20A per string.The WPC-D Solar PV String Level Monitoring Device can be directly powered by the solar array while providing reliable infomation anddata. It adopts an RS485 interface and supports the MODBUS protocol.