Specifications

Chapter 1 General Information 3
1.1 Introduction
The PCI-1757UP is a 24-bit DI/O card with PCI bus. It provides you
with 24 bits of parallel digital input/output, and emulates mode 0 of the
8255 PPI chip, but the buffered circuits offer a higher driving capability
than the 8255.
The card emulates one 8255 PPI chips to provide 24 DI/O bits. The I/O
bits are divided into three 8-bit I/O ports: A0, B0 and C0. You can
configure each port as either input or output via software. The dual
interrupt handling capability provides users the flexibility to generate
interrupts to a PC. A pin in the connector can output a digital signal
simultaneously with the card's generating an interrupt.
This card uses a DB 25-pin connector for easy and reliable connections
to field devices.
One feature gives the PCI-1757UP practical advantage in an industrial
setting. When the system is hot reset (the power is not turned off) the
PCI-1757UP retains the last I/O port settings and output values if the
user has set jumper JP1 to enable this feature. Otherwise, port settings
and output values reset to their safe default state, or to the state
determined by other jumper settings.
Numbering Convention
All numbers given in this manual are in decimal format unless
specifically noted otherwise. In particular, where a register address is
given as (Base + 32), the decimal number "32" should be added to the
base value.