All were 8-channel test boards with an 18-bit sampling resolution. The other four channels are fixed high voltage input channels with a maximum test voltage of ±2000 VPEAK. The unique modular design allows each of the two boards to have 4 channels for installing different test type modules (SUB modules) for direct current input or voltage input. This test module is easy to replace, and users can complete the module replacement by themselves. The flexible test type combination enables almost any current or voltage sensor to be connected to Xinyuan Yutong's power analyzer.