The ET-7052/PET-7052/ET-7252/PET-7252 provides 8 wet contact digital input channels and 8 source-type digital output channels. It features optical isolation for 2500 VDC of transient overvoltage protection but doesn’t provide channel-to-channel isolation. Each input channel can be used as a 32-bit counter and each output channel can drive 650 mA load. The power-on value and safe value of digital output channel are programmable. It can safely be used in applications where hazardous voltages are present.