Rockwell Automation 1756-IH16ISOE ControlLogix Sequence of Events Module - Manual (Page 119)

1 Publication 1756-UM528A-EN-P - April 2004
Appendix
B
Integrating The HiProm GPS Module
(1756HP-GPS) into a ControlLogix Sequence
of Events Module System
Overview Up to this point in this manual, the ControlLogix Sequence of Events
module is described as being used for Relative First Fault Detection. In
Relative First Fault Detection, the controller sorts the timestamps sent
by Sequence of Events module(s) to determine which transition
occurred first in an event cascade. However, each timestamp is
captured in CST format, a 64-bit number that has little meaning other
than to indicate which transition occurred first. The controller
determines an order of transitions but not the real-time of
each transition.
The most significant benefits to using the 1756HP-GPS module are:
• The 1756HP-GPS module provides a real-time reference for CSTs
captured in the ControlLogix system.
• By using the 1756HP-GPS module, you can make sure
geographically separated systems operate from a single
time reference.
• The 1756HP-GPS module can convert CST format timestamps to
a real-time reference.
IMPORTANT
u
This appendix offers a brief description of how to
use the 1756HP-GPS module with the ControlLogix
Sequence of Events module.
For more information on how to use the
1756HP-GPS module, see the 1756HP-GPS module
user manual, available at:
http://www.hiprom.com