ADLINK PCI-9524 User Manual

Page 55

Signal Connections

ADLINK Technology Inc.

Line-driver outputs

A Line-driver output stage is of differential output type, providing a
normal output and a complementary output for each signal port. A
Line-driver usually works at a much lower supply voltage and can
toggle quickly. By utilizing differential transmission topology, the
transmission distance can be extended considerably and with rel-
atively low EMI.

The line-driver used on PCI-9524 is of voltage-driving type
AM26LS31, compliant with ANSI TIA/EIA-422-B requirements.
Either one of the two complementary outputs can be regarded as
a single-ended push-pull output, and can be connected to an opto-
isolated input or a TTL input.

Opto-coupler Inputs

Opto-coupler inputs are of current input type devices, made of a
light-emitting-diode (LED) and an integrated light-sensitive transis-
tor. They accept wide input voltage ranges, provided that the input
current is limited by a series external resistor in order to protect
the integrated LED device.

Line-receiver inputs

The line-receiver, as its name implies, is used to accept signals
from line-drivers. It's of differential input type, providing a normal
input and a complementary input for each signal port.

NOTE:

1) The isolated ground (ISOGND) is shared between all iso-
lated functions in PCI-9524. Make sure the ISOGND is con-
nected to a known ground potential, only at one point in the
system.
2) Do not let the ISOGND float, nor connect it directly to a
chassis, as it may cause EMI and/or accumulate a charge that
lead to safety hazards.
3) Shield the exposed ISOGND pins, connectors, and wiring, if
possible to run a ground potential that is greater then 30-VDC.
4) Do not connect the ISOGND to analog ground (AGND), the
noise on ISOGND will ruin analog performance.