
Rockwell Automation Publication 1756-RM001I-EN-P - May 2012
91
Chapter
9
Use of Human-to-Machine Interfaces
Precautions
You must exercise precautions and implement specific techniques on HMI
devices. These precautions include, but are not restricted to the following:
•
Limited access and security
•
Specifications, testing and validation
•
Restrictions on data and access
•
Limits on data and parameters
For more information on how HMI devices fit into a typical SIL loop, see
Use sound techniques in the application software within the HMI and controller.
Accessing Safety-related
Systems
HMI- related functions consist of two primary activities: reading and writing
data.
Reading Parameters in Safety-related Systems
Reading data is unrestricted because reading doesn’t affect the operation or
behavior of the safety system. However, the number, frequency, and size of the
data being read can impact controller performance. To avoid safety-related
nuisance trips, use good communication practices to limit the impact of
communication processing on the controller. Do not set read rates to the fastest
rate possible.
Topic
Page
Содержание 1756-L6 Series
Страница 24: ...24 Rockwell Automation Publication 1756 RM001I EN P May 2012 Chapter 1 SIL Policy Notes ...
Страница 60: ...60 Rockwell Automation Publication 1756 RM001I EN P May 2012 Chapter 5 ControlLogix I O Modules Notes ...
Страница 76: ...76 Rockwell Automation Publication 1756 RM001I EN P May 2012 Chapter 6 FLEX I O Modules Notes ...
Страница 120: ...120 Rockwell Automation Publication 1756 RM001I EN P May 2012 Appendix C PFD Calculations for a SIL 2 System Notes ...
Страница 126: ...126 Rockwell Automation Publication 1756 RM001I EN P May 2012 Appendix D Checklists Notes ...
Страница 133: ...Allen Bradley Motors ...