RE: how to change the MEAN without reboot IOC?

["Mark Rivers" <rivers@cars.uchicago.edu>]

Title: how to change the MEAN without reboot IOC?

One thing to look at is the asynInt32Average device support already in asyn/devEpics.  This device support averages the callback (interrupt) readings from a device until the next time the record is processed.  So if the record is periodically processing at 10Hz it averages all the readings for 0.1 second, and if the scan rate is changed to 1Hz it automatically increases the averaging period to 1 second.  This requires no changes to the driver, beyond the required support for asynInt32 callbacks.  We run some ADCs at 1kHz callback rate, so the device support does a lot of averaging.

 

Mark

 

 

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From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-bounces@aps.anl.gov] On Behalf Of Graham Cross
Sent: Monday, March 16, 2009 10:46 AM
To: '???'
Cc: 'Mark Woodward - Hytec'; tech-talk@aps.anl.gov
Subject: RE: how to change the MEAN without reboot IOC?

 

Hi Wang,

 

Hytec currently have work in progress to provide Asyn Driver support for our ADCs. We are currently working on the 8401 ADC code and will support the 8413 next. This new support includes functionality to allow run time modification of many parameters including sampling rate, collection mode, number of samples and number to average over.

You will have to stop the ADC sampling to make a change but you will not need to reboot the IOC.

 

The specification for this work has been driven by requirements for Diamond and agreed with them.

 

When the code is tested and approved it will be available to download, hopefully soon.

 

Regards,

Graham Cross
Hytec Electronics Ltd

 

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From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-bounces@aps.anl.gov] On Behalf Of ???
Sent: 16 March 2009 02:20
To: tech-talk@aps.anl.gov
Subject: how to change the MEAN without reboot IOC?

 

hi,all

I am using the hytec8401 and the correponding hy8401ip driver from Diamond. The record can be follows:

record(ai,"AI")
{
 field(DTYP,"Hy8401ip")
 field(INP,"#20S0 @ MEAN=10)
}

Sometimes i want to change the samples to average. But i do not know how to change this field without reboot the ioc? AI.INP looks like can not be change in running. By the way i use edm.

Wang Qisheng
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