User manual

110 Rockwell Automation Publication 1769-UM011I-EN-P - February 2013
Chapter 7 Develop Applications
Service communication is any communication that you do not configure through
the I/O configuration folder of the project.
• The system overhead time slice specifies the percentage of time (excluding
the time for periodic or event tasks) that the controller devotes to service
communication.
• The controller performs service communication for up to 1 ms at a time
and then resumes the continuous task.
To select a system overhead percentage, perform this procedure.
1. In the Controller Organizer of RSLogix 5000 programming software,
right-click on your controller and choose Properties.
The Controller Properties dialog box appears.
2. Click the Advanced tab.
3. From the System Overhead Time Slice menu, choose a percentage.
System overhead time slice functions include:
• communicating with programming and HMI devices, such as RSLogix
5000 software.
• responding to messages.
• sending messages.
The controller performs system overhead functions for up to 1 millisecond at a
time. If the controller completes the overhead functions in less than one
millisecond, it resumes the continuous task.