BEKA BA484DF, Руководство пользователя

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2. OPERATION
Fig 1 shows a simplified block diagram of the
BA488CF Fieldbus Display. When the optional
alarms and external switches are not used, the
instrument only requires a two-wire connection to
the fieldbus.
How much of the BA488CF configuration can be
performed via the fieldbus depends upon the
instrument version and the system host.
Parameters that can not be configured via the
fieldbus can be set via the six front panel push
buttons. Menus enable the required standard
display format to be selected and the units of
measurement, plus tag information for each
displayed fieldbus variable to be entered. Each
fieldbus variable may be individually offset and
scaled, and when a standard screen including a
bargraph is selected, the limits of each bargraph
can be set. Alarm function and setpoints can also
be configured.
Fieldbus configuration files for the BA488CF may
be downloaded from the appropriate Fieldbus
Foundation or Profibus web sites, or from the
BEKA associates web site at www.beka.co.uk.
Fig 1 Simplified block diagram of BA488CF
2.1 Controls
The user can scroll through the display screens by
operating the
Up or Down push-buttons. The
number of screens available depends upon how
the BA488CF display has been configured. If one
fieldbus variable per screen has been configured,
eight screens will be present; if four fieldbus
variables per screen have been configured, only
two screens will be available.
Irrespective of the number of fieldbus variables
assigned to the BA488CF, the instrument always
has provision for displaying eight variables.
Unassigned inputs are displayed as zero with a
bad data warning i.e. light digits on a dark
background. When a custom display format,
which requires programming is used, the number
of fieldbus variables displayed may be defined.
If enabled, operating the P and Up push buttons
simultaneously activates the Quick Access Menu,
allowing the user to adjust the display contrast
without providing access to any of the other
configuration parameters. Additional security may
be provided by an optional access code.