Yep. Thought about exactly that about an hour after I wrote it. Thanks.
Corey
|---------+---------------------------->
| | "Johnson, Alex |
| | (Foxboro)" |
| | <ajohnson@Foxboro|
| | .com> |
| | Sent by: |
| | foxboro-bounce@fr|
| | eelists.org |
| | |
| | |
| | 06/25/2003 05:26 |
| | PM |
| | Please respond to|
| | foxboro |
| | |
|---------+---------------------------->
>------------------------------------------------------------------------------------------------------------------------------|
|
|
| To: foxboro
|
| cc:
|
| Subject: Re: [foxboro] CPU loading Accuracy in STATION block (was CP
Load ) |
>------------------------------------------------------------------------------------------------------------------------------|
Two different issues, Corey.
The clock isn't wobbling. It's just that the granularity on loading
measurements is the granularity of the clock. We can't tell if the machine
is busy for those 20ms or idle hence the error.
The clock runs on schedule, the BPCs are predictable, but the STATION block
cannot see how full a 20ms interval is.
In 500ms system, a 20ms interval is only 4% error, but it is 10% of a 200ms
interval and that is a big difference.
Make sense?
Alex Johnson
Invensys Systems, Inc.
10707 Haddington
Houston, TX 77043
713.722.2859 (office)
713.722.2700 (switchboard)
713.932.0222 (fax)
ajohnson@xxxxxxxxxxx
For the latest information on ArchestrA, go to
www.invensys.com/Archestra.html.
_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
foxboro mailing list: http://www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave