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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 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.
Link Master Configuration
An option to set a device as a basic or link master device. Only devices
that are capable of being a Link Active Scheduler have this option on
the Field Communicator.
Link Scheduling time
Link Scheduling time is a link-specific time represented as an offset
from Data Link Time. It is used to indicate when the LAS on each link
begins and repeats its schedule. System management uses it to
synchronize function block execution with the data transfers scheduled
by the LAS.
Lithium Ion Power Module
A Lithium Ion (Li-Ion) battery used to power the 475 Field
Communicator. The battery has a green, 6-pin power supply/charger
connector. See Figure 2-1 on page 12 for the location of this
connector. The battery must be charged by the Field Communicator
power supply/charger with the matching green connector.
Online licensing
A feature in the Field Communicator Easy Upgrade Utility to select and
download new licenses that enable additional functionality in the 475
Field Communicator. You can order and download licenses for Easy
Upgrade and Fieldbus application. The 475 Field Communicator must
be licensed for the Easy Upgrade option before you can download a
license for the Fieldbus application. See the Easy Upgrade Utility Help
for more information.
Personal computer (PC)
Synonymous with microcomputer, a computer that serves one user in
the office or the home.
Polling
A method of sequentially interrogating a network to determine which
devices are present.
Process variable (PV)
A process parameter that is being measured or controlled (for
example, level, flow, temperature, mass, or density).
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