网址忘记了，下边是我以前摘的笔记

QUESTION:
How can you change the acquisition cycle of Alarm Logging?
ANSWER:
In the Registry you can define for the message system the update time for the event variables and the process values. If you increase the update time, you can improve performance. But you must pay attention to the necessary message speed. You must make the entries manually by creating the code at the following point in the Registry:
1. Start menu > Run, enter "regedit".
2. Find the code:
HKEY_LOCAL_MACHINE\SOFTWARE\SIEMENS\WINCC\Alarm Logging\CONSTANTS
3. Add two new values (right-click\new\DWORD value)
"CycleAlarms"= "00000000" // Message variable cycle (default value 0)
"CyclePValues"= "00000000" // Process value variables (default value 3)
You can enter the following values for the update time in the Registry values:
0 = Upon change (500ms)
1 = 250ms (DO NOT USE, INCREASES SYSTEM LOAD)
2 = 500ms
3 = 1s
4 = 2s
5 = 5s
6 = 10s
7 = 1min
8 = 5min
9 = 10 min
10 = 1h
IMPORTANT
Basically, no warranty can be given for direct changes in the registry database, because this is entirely the responsibility of the user. In any case it is recommended to make a backup of the registry before proceeding as described below. Furthermore, these settings are computer-specific. This means that when copying the project to another computer, the settings have to be made again.

其中归档周期和变量刷新周期都能改的