Industrial Universal PCI card with 12 Digital Inputs and 16 Digital Outputs. The PCI-M512/PCI-M512U provides battery-backup 512 KB SRAM, 12-bit DI and 16-bit DO. In addition, the PCI-M512U supports both 5 V and 3.3 V PCI bus, while the PCI-M512 supports 5 V PCI bus only..