RE: CA loss package on 1 Hz rate

["Liyu, Andrei" <liyua@ornl.gov>]

Hi, Motoki

If I am not mistaken
1. dbGetLink() uses CA monitor if PV is placed on another IOC.
2. I have misunderstanding concerning PV gateway. If it is CAGateway
then you have additional buffer (=possible trouble). My experience (6
months ago) gave awful result at SNS. Then Jeff Hill came and he found
one problem and fixed that. But I didn't use CAGateway after that.
3. CaArchive uses CA monitor if you setup "Monitor" in PV definition. In
another case (without Monitor) CaArchive uses caget or monitor.
(CaArchive does "investigation" or depends of other parameters of engine
level. Manual is not clear and I don't remember well Kay's explanation
because I don't use CaArchive without Monitor.) 
About timeout definition in CaArchive. I don't know concerning your
previous explanation "1s CaArchive vs 1.0001s PV period". From my small
experience it works well. I wrote 1s in PV definition and data by
monitor come ~1Hz rate (data timestamp is defined from trigger; 1 Hz
trigger is little less - little more 1 s). But I don't remember any
suitable information about that from CaArchive manual.

About your variants.
	I am sorry but I haven't sense what is difference in your 4
variants.
	If CalcRecord is the same and 4 variants work in the same time
so "miss" ":-)" problem is not in IOC 1st. IOC 2nd has one (!) CA
Channel for CalcRecord - this CaRepeater's care. (Jeff, am I correct?)
	So IOC 1st with CalcRecord and LAN are Ok. CaRepeater of IOC 2nd
is Ok too. Then I don't know :-(

Have a good day, Andrei.

-----Original Message-----
From: Motoki Ooi [mailto:ooi@cens.tokai.jaeri.go.jp] 
Sent: Tuesday, August 23, 2005 9:25 PM
To: tech-talk@aps.anl.gov
Cc: Liyu, Andrei
Subject: Re: CA loss package on 1 Hz rate

Hi Andrei

I'm sorry, I was misunderstanding about caget.
It was not caget nor camonitor method.
What I want to say is "dbGetLink" using in 'aiRecord.c' and other
record.

In the following four case, No 1 and No 3 is almost perfect.
But  once AiRecord ( or PV gateway) on IOC 2nd is used,
(No 2 and No 4) there is some data loss in archived or camonitored data.
1. CalcRecord(IOC 1st) => LAN => camonitor(IOC 2nd)
2. CalcRecord(IOC 1st) => LAN => aiRecord(IOC 2nd) => camonitor(IOC 2nd)
3. CalcRecord(IOC 1st) => LAN => Channel Archiver(IOC 2nd)
4. CalcRecord(IOC 1st) => LAN => aiRecord(IOC 2nd) => Channel 
Archiver(IOC 2nd)
Access method of camonitor and Channel Archiver is differ from AiRecord 
or dbGetLink (dbPutLink)?

Motoki Ooi


Liyu, Andrei wrote:

>Hi,
>	I don't use any (sync or async) caget method. I use monitor
>method. So I don't lost data like your case. Also I use caget for
simple
>(=test) program. For normal program monitor is better.
>	I also don't care about CPU loading in my case. I control that
>and I know when program uses that. It is tied to trigger and I know how
>many mc uses BLM thread after trigger. After that CPU is unloaded and
>CAS can take everything.
>
>Andrei.
>
>-----Original Message-----
>From: Motoki Ooi [mailto:ooi@cens.tokai.jaeri.go.jp] 
>Sent: Monday, August 22, 2005 9:08 PM
>To: Liyu, Andrei; tech-talk@aps.anl.gov
>Subject: Re: CA loss package on 1 Hz rate
>
>  
>
>  
>