Select A System Overhead Percentage - Allen-Bradley SoftLogix 5800 User Manual

Chapter 2 What is the SoftLogix System?
Select a System Overhead
Percentage
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The Controller Properties dialog box lets you specify a percentage of controller
time (excluding the time for periodic tasks) that is devoted to communication
and background functions.
1. In the Logix Designer application, from the Controller Organizer, right-
click the controller and choose Properties.
2. Click the Advanced tab.
3. In the System Overhead Time Slice box, enter a percentage.
The system overhead function interrupts the continuous task. The percentage
you specify determines the amount of the continuous task to allocate to system
overhead functions, which include the following:
• Communicating with programming and HMI devices (such as
RSLogix 5000 software)
• Responding to messages
• Sending messages, including block-transfers
• Re-establishing and monitoring I/O connections (such as RIUP
conditions); this
during program execution
• Bridging communication from one communication device to another
communication device across the virtual chassis
This function allows the controller to take care of communication requests that
occur from other controllers or from queued requests from within the controller's
application program. If communication is not completing fast enough, increase
the system overhead percentage.
Because the SoftLogix controller runs natively on your computer's Pentium CPU,
the default setting of 10% yields satisfactory performance for most applications.
Rockwell Automation Publication 1789-UM002K-EN-P - January 2015
include normal I/O communication that occurs
does not