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<== Date ==> | <== Thread ==> |
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Subject: | RE: increasing scan rates |
From: | [email protected] (Peregrine McGehee) |
To: | "'Jeff Hill'" <[email protected]>, "'Geoff Savage'" <[email protected]>, "[email protected]" <[email protected]> |
Date: | Fri, 14 Aug 1998 13:46:13 -0600 |
For rates less than your vxWorks clock rate (default 60Hz) you can add periodic scan rates to EPICS by modifying menuScan.ascii as described in the IOC Applications Developers Guide. For R3.13 see Chapter 14. Database Scanning. The caveat is that your specified scan rates in seconds should map to a integral number of clock ticks - otherwise you will not get the timing you expect. I've routinely used 20Hz (.05 second) scan rates for servo loops. This would be implemented by adding the following to the menu(menuScan) definition: menu(menuScan) { : choice(menuScan__5_second, ".05 second") } With a 60Hz vxWorks clock, this scan task gets processed once every 3 ticks. Aloha, Peregrine Peregrine M. McGehee [email protected] LEDA Control System Project Engineer (505) 667-3273 Accelerator Controls & Automation Group Los Alamos National Laboratory