Re: Data transport problem with CA

[Mark Rivers via Tech-talk <tech-talk at aps.anl.gov>]

Hi Jörn,

> I can see reasonable Data when calling caget with a low number of elements

> to read, but fails with a warning "virtual circuit disconnect" when

> attempting to read the full image and all data is shown to be 0.

> Read operation timed out: some PV data was not read.

The error message you got was a timeout.  So I suggest increasing the timeout in the caget command above the default of 1.0.

 caget -w5 imagePV:ArrayData

Mark

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From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Jörn Dreyer via Tech-talk <tech-talk at aps.anl.gov>
Sent: Tuesday, January 31, 2023 7:31 AM
To: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Re: Data transport problem with CA

 

HI Yong,

Am Dienstag, 31. Januar 2023, 14:17:17 CET schrieb Hu, Yong:
> Hi Jörn,
>
> Firstly you missed one ‘0’ in your caget’s EPICS_CA_MAX_ARRAY_BYTES which is
> 40MB (not 400MB as you configured in Phoebus).
Thar difference was a typo in my mail.
>
> Having said that, 40MB should be enough for the ASI1600MM if your
> ‘imagePV:ArrayData’ is 16-bit data type: 4656*3520*2 = 32778240 < 40MB.
> What is your settings for the data type ‘imagePV:ArrayData’’? 16-bit,
> 24-bit, 32-bit?
>
The datatype is UINT16.
 
> Also, it is worth checking the settings of EPICS_CA_MAX_ARRAY_BYTES inside
> your IOC (i.e. st.cmd). I guess it is big enough, otherwise you will have
> trouble with the Phoebus reading. Anyway, what is the number you used for
> the ASI1600MM IOC?
EPICS_CA_MAX_ARRAY_BYTES=500000000

Regards,

Jörn

>
> Cheers,
> Yong
>
> From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Jörn Dreyer via
> Tech-talk <tech-talk at aps.anl.gov> Date: Tuesday, January 31, 2023 at 6:33
> AM
> To: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
> Subject: Data transport problem with CA
>
> Hi,
>
>
> I run into a problem with transporting the data of an areaDetector image
> over CA. It works in one case, but not the other.
>
> I have one IOC that reads out three cameras
>
>
> 1) Two basler cameras with 659*494 pixels
>
> 2) One ASI 1600MM with 4656 x 3520 pixels
>
>
> Now to the problem:
>
> The Basler cameras do not make any problem, only the ASI1600MM is affected:
>
>
> It works in Phoebus when setting org.phoebus.pv.ca/max_array_bytes=400000000
>
>
> I can see reasonable Data when calling caget with a low number of elements
> to read, but fails with a warning "virtual circuit disconnect" when
> attempting to read the full image and all data is shown to be 0.
>
>
> The first lines of caget output are:
>
>
> caget imagePV:ArrayData
>
> Read operation timed out: some PV data was not read.
> imagePV:ArrayData 16389120 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0 0 0 0
>
> Limiting the amount of data read:
>
>
> caget imagePV:ArrayData -# 100
> imagePV:ArrayData 100 3520 3888 4080 4480 4560 4992 4480 4864 5136 5184 5536
> 6096 5488 4672 3024 2192 1536 1264 848 944 816 608 560 640 480 496 464 432
> 544 416 336 400 336 33 6 464 320 400 480 352 304 336 256 304 272 240 320
> 272 288 272 288 256 320 256 304 240 224 304 288 240 240 256 256 288 320 288
> 304 256 304 272 256 240 288 256 352 304 320 304 304 288 304 256 288 28 8
> 320 352 336 368 368 304 320 288 352 336 288 304 320 272 224 272 256
>
>
>
> The environment vaiable EPICS_CA_MAX_ARRAY_BYTES is set to 40000000 to match
> the setting for phoebus.
>
>
> What setting might need to be changed to get that working?
>
>
> Regards,
>
>
> Jörn