Siemens OP17, Equipment Manual

Page: 52 / 198

5-2
Equipment Manual OP7, OP17
Release 04/99
5.1 Screen Entries
Screens consist of entries. Every screen may contain up to 99 entries. Irre-
spective of the configured number of lines, precisely one entry is displayed
per display page on the OP. Lines which may have not been fully configured
are displayed as blank lines.
An example of a screen entry is the two lines in the afore mentioned example
(figure 5-1)
Furn1 temp.: 80
°
C
Furn1 cont.: 1200 l
.
A screen entry consists of the following components:
entry text
The static text contains explanations for the operator. It may also include
information on how the soft keys have been assigned.
fields for the
– output of PLC actual values, date, time,
– input of PLC tags which are immediately transferred to the PLC after
being entered,
– combined I/O of PLC tags.
soft keys
Different function calls for the different screens are assigned to the soft keys.
The configuration defines the intervals at which PLC values are updated, i.e.
read again from the PLC and displayed.
With large screens containing more than 159 actual values or setpoint-actual
values, ”partial screen updating” is automatically enabled. To enhance per-
formance, only those values are updated which are currently present on the
display. This may mean that an older value is briefly displayed when scrol-
ling through screen entries. Updating of the visible actual values is faster as a
result, however.
Output fields display actual values of the PLC in numerical or symbolic
form; input fields define tags in numerical or symbolic form. In input fields,
the flashing cursor is visible.
For symbolic I/O fields, you can configure up to 256 text elements which you
can call on the OP using a selection field and apply to the screen entry.
With inputs of numerical values, configured number formats and limit values
apply with respect to the number of places before and after the decimal point.
Displaying a
screen entry
Components of a
screen entry
Updating values in
screen entries
I/O fields