The PCI-1751 and PCI-1750 are add-on cards for the PCIbus that provide 48 TTL digital I/O channels and 32 isolated high voltage 0 to 48 vdc digital I/O channels, respectively. Other features include dual interrupt sources, output port settings on system start-up with PCI-1751 and dry contact support for PCI-1750. Both cards have passed the CE Mark test and meet Class B EN55022 EMI standards. The PCI-1750 has 16 digital input and output channels with 2500 vdc isolation protection. The input channels support wet contact and dry contact connections, and an on-board isolated counter and 32-bit internal timer can count events and generate watchdog interrupts. The PCI-1751 provides 48 TTL digital input or output lines and emulates mode 0 of the 8255 PPI chip. Users can set each I/O port for either input or output.