Emerson 375 User Manual page 108

G-iv
Intrinsic Safety
Circuits that are designed to limit the amount of energy consumed or
provided to field devices to levels below those that are required to
ignite specific types of hazardous materials under fault and no fault
conditions.
Also a method of providing safe operation of electronic
process-control instrumentation in hazardous areas, such as
flammable environments. IS systems keep the available electrical
energy in the system low enough that ignition of the hazardous
atmosphere cannot occur.
Intrinsic Safety barrier
A physical entity that limits the current and voltage into a hazardous
area in order to satisfy Intrinsic Safety requirements.
IrDA
Infrared Data Association, a non-profit trade association that
establishes standards for infrared communications between devices
such as personal computers, printers, and handheld devices.
Link Active Scheduler (LAS)
The bus arbiter for the segment. The LAS, recognizes and adds new
devices to the link, removes non-responsive devices from the link,
and distributes Data Link (DL) and Link Scheduling (LS) time on the
link.
Link master
A Link Master device controls when devices access the fieldbus and
executes the link schedule which synchronizes communications with
function block execution on the fieldbus. The H1 card or any field
device that supports Link Master functionality can function as a Link
Master device. Only one Link Master device can be active at a time
on the fieldbus segment. This device is called the LAS.