National Instruments Quadrature Input Module FP-QUAD-510 - Manual (Page 9)

© National Instruments Corp. 9 FP-QUAD-510
Note If the axis is stopped with the index condition true,
then reading the status bit causes the bit to reset to 0.
However, since the index condition is still true, the bit is
immediately latched back to 1.
If the Reset on Index attribute (see Position Counter Operation ) is
selected, then the index status bit does not need to be read between
successive index pulses in order for the position counters to reset.
The position counters respond to index pulses as programmed
regardless of the state of the index status bit.
Isolation and Safety Guidelines
Caution Before you connect any circuits that may
contain hazardous voltages to the FP-QUAD-510,
read the following information.
This section describes the isolation of the FP-QUAD-510 and its
compliance with international safety standards. The field wiring
connections are isolated from the
backplane provided by the
terminal base with an optical and galvanic isolation barrier
designed and tested to provide protection against fault voltages of
up to 2,500 Vrms. In addition, the FP-QUAD-510 provides double
insulation (compliant with IEC 1010-1) for working
common-mode voltages of 250 Vrms. Safety standards (such as
those published by UL and IEC) require the use of double
insulation between hazardous voltages and any human-accessible
parts or circuits.
Never try to use any isolation product between human-accessible
parts (such as DIN rails or monitoring stations) and circuits that
may be at hazardous potentials under normal conditions, unless the
product is specifically designed for such an application, as is the
FP-QUAD-510.
When you use a product like the FP-QUAD-510 in applications
with hazardous potentials, follow these guidelines to make sure
your total system is safe:
• The safety isolation of the FP-QUAD-510 is from input to
output, not between channels on the same module. If any of the
channels on a module are wired at a hazardous potential, make
sure that all other devices or circuits connected to that module
are properly insulated from human contact.
• Do not share the external supply voltages (V and C on the
terminal base) with other devices (including other FieldPoint
devices), unless those devices are isolated from human contact.