48 TTL level digital I/O lines.
Emulates mode 0 of 8255 PPI
Buffered circuits provide higher driving capability
Interrupt handling
Interrupt output pin for simultaneously triggering external devices with the interrupt
High density SCSI 68-pin connector
Output status readback
Two 16-bit timers can be cascaded to one 32-bit timer, and can generate watchdog timer interrupts
One 16-bit event counter can generate event interrupts
Keeps port I/O settings and digital output states after hot system reset
Supports dry contact and wet contact
Industrial AC/DC I/O devices monitoring and control
Relay and switch monitoring and control
Parallel data transfer
Sensing the signals of TTL, DTL, CMOS logic
Driving indicator LEDs
Two lines in each I/O port (C0 and C4) and two of the three counter outputs (Timer 1 and Counter 2) are connected to the interrupt circuitry. The "Interrupt Control Register" of the PCI-1751 controls how the combination of the 6 signals generates an interrupt. Two interrupt request signals can be generated at the same time, and then the software can service these two request signals by ISR. The dual interrupt sources provide the card with more capability and flexibility.
The PCI-1751 includes one 8254 compatible programmable timer/counter chip which provides three 16-bit counters. Each has 6 operation modes. Counter0 and Counter1 can be used separately as Timer0 and Timer1 or can be cascaded to create one 32-bit timer. Both Timer 1 and Counter 2 can generate interrupts to the computer. Please refer to hardware manual for more information on the operation modes of the counter chip.