Burkert 8746, Руководство по эксплуатации

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Setting and operation
Type 8746 Profibus, 8746 Analogue
10.9 choose the source giving the set-
point value (Mfc)
The process set-point value can be set by different sources. You
can choose which source is active at a time. The source for the
set-point value can be changed during operation.
If you change the source for the set-point value, then the operating
mode of the MFC is changed.
To change the source for the set-point value, change the setting
of the parameter set-point value source with the Bürkert Com -
municator software. To connect the product to the Bürkert Com -
municator software, refer to chpt. 10.4 .
On a product variant Profibus you can alternatively change the
related object. Refer to the related procedure in the product-specific
help in the documentation of the initiation files. Download the initi -
ation files and the related documentation at country.burkert.com .
The setting of the parameter
set-point value source
is
kept after a restart, except when the product performs the
function analyze system .
The possible choices for the parameter set-point value source
are:
•
Product variant Profibus:
automatic :
the set-point value is set
via the fieldbus.
•
Product variant Analogue: analog set-point value : the set-
point value is set via the analogue input.
•
manual set-point value : to manually give in a set-point value
for testing purposes or to make sure that the set-point value is not
overwritten by other fieldbus participants.
•
stored set-point value : to use a fixed set-point value (w).
When the product is restarted the fixed set-point value remains
active.
•
Open-loop control mode : to directly set the set-point position
(y) to the control valve. The value that is given in the menu
actuator parameter actuating variable
is
the set-point position (y) that is used. A restart of the product
sets the set-point position (y) to zero.
•
analyze system
: the product operates in the normal operating
mode, but according to a predefined chronological sequence
with set-point values. Use the resulting diagram in combination
with the graphical representation of process values to analyse
the system with the Bürkert Communicator software.
10.10 Set-point values without
communication (Mfc Profibus)
The function makes it possible to specify the set-point values of
an MFC even if the communication with the external set-point
value provider (for example a PLC) is broken. If the function is
used, then the set-point is kept constant.
By using the function, the fluid can continue to flow even
if the communication is broken.
▶
Make sure that the process is safe when you use the
function.
→
To use the function, refer to the related procedure in the prod -
uct-specific help in the documentation of the initiation files.
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