Advantech PC-LabCard PCI-1784 - Manual (Page 6)

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Counters
The PCI-1784 has four independent 32-bit counters. The maximum
quadrature input rate is 2 MHz, and the maximum input rate in counter
mode is 8 MHz. You can individually configure each counter for
quadrature decoding, pulse/direction counting or up/down counting.
Digital Input and Interrupts
The PCI-1784 provides four digital input channels. Each channel
accepts digital input as an index input for a rotary encoder or as a home
sensor input for a linear encoder. The card can generate an interrupt to
the system based on a signal from its digital inputs, overflow/underflow
and over-compare/under-compare of its counters, or on a programmed
time interval. It can repeatedly generate interrupts at any time interval
you specify, from 20 micro second to 51 second. These interrupts let
you precisely monitor the speed of a control system.
Flexible Digital Output function
The PCI-1784 provides four digital output channels. Each channel
accepts digital output as a normal TTL output for a rotary encoder, or as
an indicated output with pulse/level mode for a linear encoder. The PCI-
1784 can generate an indicated output based on a signal from over-
compare/under-compare of its counters. The pulse width of an indicated
output is depends on the counter clock or clear interrupt.
Special Shielded Cable for Noise Reduction
The PCL-10137H shielded cable is specially designed for the PCI-1784
for reducing noise. Its wires are all twisted pairs, and the input signals
and output signals are separately shielded, providing minimal cross talk
between signals and the best protection against EMI/EMC problems.
Keeping the Counter Values and the Output Status after system
reset
Users can independently use the four counter channels. When the
system is hot reset (power not shut down), the PCI-1784 can either
retain the last counter values and the output status, or return to its