Siemens SIMATIC NET Manual page 59

Table 5-1
Parameter Possible Settings / Significance
/ Function / Function
Scan cycle Here, you make the settings to control
time updating by the OPC Server.
The scan cycle time decides how often
the OPC server updates the values the
OPC items.
Access You can specify the access rights to
protection individual variables or variable groups for
each specific protocol. You can, for
example, prevent variables calculated
internally by the controller from being
overwritten.
As default, no access protection is
activated.
VFD VFD (Virtual Field Device) is the neutral
description of a device used in FMS.
Communication connections (FMS
connections) are then configured for the
VFDs in project engineering.
Here, you inform the OPC server of the
required VFDs. During project
engineering, you then assign the VFD to
the FMS connection. When accessing
variables in the PC application, you also
reference the VFD.
Extra function: creating the object
dictionary
Here, you can also create the object
dictionary (OD) belonging to a VFD. The
FMS variables (name and structure) are
defined in the object dictionary.
Connection Here, you can make the settings required
parameters for communication for services that do
not require specific connections to be
configured in project engineering.
Segmenta- Special settings for providing the data
tion buffers independent of specific
connections.
Use
symbols
Please note that the parameters are described in detail in the online help for each
individual dialog in NCM PC.
Commissioning PC Stations - Manual and Quick Start
Release 5/2005
C79000-G8976-C156-07
5 Project Engineering for the OPC Server
Can be set for a specific protocol
x x x x x
x x x x x
x
x
x
x
x x x x
x x x x
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