Basic Concepts for Programming an S7-200 CPU
4-42
S7-200 Programmable Controller System Manual
A5E00066097-02
4.11 Background Time
You can configure the percentage of the scan cycle that will be dedicated to
processing communications requests that are associated with a RUN mode edit
compilation or STL status gathering. As you increase the percentage of time that is
dedicated to processing communication requests, you increase scan time, which
makes your control process run more slowly.
Select the Background Time tab to set the scan cycle time-slice that is allowed for
background communications (Figure 4-24). Edit the properties for the
communications background time and then download the modifications to the
CPU.
The default percentage of the scan dedicated to processing communications
requests is set to 10%. This setting was chosen to provide a reasonable
compromise for processing compilation/status operations while minimizing the
impact to your control process. You can adjust this value by 5% increments up to a
maximum of 50%.
System Block
OK Cancel
Configuration parameters must be downloaded before they take effect.
PasswordPort(s) Retentive Ranges
Analog Input Filters
Output Table Input Filters
Pulse Catch Bits
Background Time
Select Communication Background Time (5 - 50%)
Not all PLC types support every System Block option. Press F1 to see
which options are supported by each PLC.
Default = 10%
10
Figure 4-24 Background Time Configuration Screen
To Next Page
Loading...
