Emerson 475 User Manual page 106

G-iv
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 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 2-3 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 F fieldbus application.
OUNDATION
The 475 Field Communicator must be licensed for the Easy Upgrade option before you
can download a license for the F fieldbus application. See the Easy
OUNDATION
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).
Resource CD
A CD included with the purchase of a 475 Field Communicator. It contains electronic
copies of product documentation, the install file for the Easy Upgrade Utility, and the
latest system software and device descriptions at the time the CD was created.
Segment (Fieldbus only)
The section of a fieldbus that is terminated in its characteristic impedance. Segments
are linked by repeaters to form a complete Fieldbus.
Shout/deaf mode
A communication mode in the 475 Field Communicator where the amplitude of the 475
signal is increased. The 475 Field Communicator determines when to enter this mode.
The icon (with a solid or hollow heart) indicates when the 475 Field
Communicator is in this mode.