Re: MRF Delay Compensation Function

["Wang, Lin via Tech-talk" <tech-talk at aps.anl.gov>]

Hi Guobao,

CSNS has passed the national inspection and acceptance successfully in 2018, and is still in stable operation now.

Thanks for raising these very practical questions. To be honest, I did not do these tests, so I have no idea, and I am looking forward to more experience sharing about the delay compensation function.

Thanks,

Lin

-----Original Messages-----
From:"Shen, Guobao" <gshen at anl.gov>
Sent Time:2020-02-19 10:43:12 (Wednesday)
To: "Wang, Lin" <wanglin at ihep.ac.cn>
Cc: tech-talk <tech-talk at aps.anl.gov>
Subject: Re: MRF Delay Compensation Function

Hi Lin,

How is everything at CSNS?

That is good that you did get a chance to have a simple test.

During your test, did you observe any jitter issue?

Were you able to turn on and off the delay compensation function smoothly?

Or do you have to go with a work around solution, for example leaving the compensation function on and putting zero delay there?

When you disable the delay compensation, how about the signal quality? Any performance issue?

Thanks,

Guobao

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---

From: Wang, Lin <wanglin at ihep.ac.cn>
Sent: Tuesday, February 18, 2020 7:59:54 PM
To: Shen, Guobao <gshen at anl.gov>
Cc: tech-talk <tech-talk at aps.anl.gov>
Subject: Re: MRF Delay Compensation Function

 

Hi Guobao,

In 2018, in the task of event timing system prototype of the HEPS-TF project, I built a test stand with MRF VME-EVM-300 and VME-EVR-300, and did a simple test of the delay compensation function.

Hardware platform:

MVME-5100

VME-EVM-300

VME-EVR-300

Software platform:

Debian 8.7 32-bit running in VirtualBox

vxWorks 6.8

PSI fork of mrfioc2 [1]

EPICS-3.14.12.3

devlib2-2.8

The caQtDM OPI (included in mrfioc2) developed by PSI was very straightforward and contained everything I wanted. I enabled the delay compensation mode in both VME-EVM-300 and VME-EVR-300 as well as some other configurations, and set a appropriate delay compensation target value to VME-EVR-300, then the internal FIFO in VME-EVR-300 did the compensation.

Actually, the only test I did was switching optical fiber from 3 meter to 6 meter, and it turned out that the compensation function worked properly. Due to my work assignment, I did not do any further test since then. Shortly, I will send you a memo document written in Chinese which records my test procedure. 

Regards,

Lin

[1] https://github.com/paulscherrerinstitute/mrfioc2

-----Original Messages-----
From:"Shen, Guobao via Tech-talk" <tech-talk at aps.anl.gov>
Sent Time:2020-02-19 02:43:22 (Wednesday)
To: Tech-Talk <tech-talk at aps.anl.gov>
Cc:
Subject: MRF Delay Compensation Function

Hi all,

Is there anyone who has been using MRF EVM-300 delay compensation function for any purpose, in the lab, test stand, real machine, etc?

If yes, would you mind to share us your experience?

 

Thanks,

Guobao

 

--------

Guobao Shen

gshen at anl.gov

Controls Group Leader

Advanced Photon Source

Argonne National Laboratory

9700 S. Cass Avenue, Lemont, IL 60439