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IOO (OMC)
kenta.tanaka - 9:13 Tuesday 25 October 2022 (22648) Print this report
OMC Beacon ASC models are ready

I made the two 64 kHz models for OMC Beacon ASC. 

"k1sendbeacon" is the model for sending the 24 kHz excitation signal to ETMX in k1ex0. (fig. 1)

"k1ascbeacon" is the model for the demodulation of a 24 kHz beacon signal received with OMC REFL RFQPDs and passes the demodulated signal to the k1omc model. (fig. 2)

Now I have compiled both two models, but they have not been installed yet. 

And I would like to make the receiver port in the k1omc model to receive the signal from the k1ascbeacon model, but I hear the k1omc model is modifying now. So, I am waiting to finish it.

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takahiro.yamamoto - 11:37 Tuesday 25 October 2022 (22662) Print this report
These models will not work as you hope.

Front-ends at the end stations aren't connected to the Dolphin network.
They are connected to RFM-X and RFM-Y netwroks. (Note: X-arm and Y-arm are different networks.)

On the other hand, front-ends at the corner station except K1LSC and K1ASC aren't connected to RFM networks.
They are connected to the Dolphin network.

So sine and cosine signals as LO on k1sendbeacon in K1EX1 cannot be sent to k1ascbeacon in K1OMC via the "cdsIPCx_PCIE" block.
And also, DCPD signals on k1aso in K1OMC cannot be sent to the sender model in K1EX1.

For LO signals, the most simple solution is to put "cdsOscFixedPhase" block on k1sendbeacon and k1ascbeacon.
Phase of LO signal generated by this block is defined as 0 at GPS=0.
So we can obtained synchronized sinusoidal signals on different models even if front-ends are also different.
In this way, digital clock delay of Dolphin, RFM, and Shmem communication can be removed.

For the DCPD signal as trigger reference, I have no good idea.
Possible solution is to send signal from k1aso in K1OMC to a some model on K1LSC or K1ASC via Dolphin network.
After then signals received on K1LSC or K1ASC can be sent to k1sendbeacon via the RFM-X network.
In this case, you must use the "card=0" of "cdsIPCx_RFM" block for communications via the RFM-X network instead of the "cdsIPCx_PCIE" block.
("card=1" for the RFM-Y network.)
Please take care the digital clock delay. In this way two digital clock delay is occurred.
kenta.tanaka - 19:12 Thursday 27 October 2022 (22709) Print this report

Thank you for advice, Yamamoto-san

I modified both models based on your advice. I confirmed both models are compiled after the modification.

takahiro.yamamoto - 22:54 Friday 28 October 2022 (22728) Print this report

I remembered that RFM was able to be used only on the model that sampling rate was lower than or equal to 16kHz.
In fact, RFM communication for sending OMC DCPD signal from k1lsc to k1sendbeacon is always failure as shown in Fig.1.

I guessed this limitation comes from the light travel time over the 3km arm.
In 65kHz model, sampling interval is ~15us. So all calculation defined on the matlab/simulink model must be finished within 15us.

RFM communication spends at least 10us as 3km light travel time (maybe additional delay exists e.g. media conversion overhead, 3km round trip like TCP protocol, etc.).
Anyway, there is no enough time to process the user code.
So we need to re-consider the way to shut excitation signal out.

According to the Ushiba-kun's suggestion, beacon feedback on the k1ascbeacon should be shut out after lockloss ASAP but shut out speed of test mass excitation on k1sendbeacon may not require such a high speed. Guardian or Ezca block may be enough.

 

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kenta.tanaka - 1:29 Friday 04 November 2022 (22790) Print this report

I modified the trigger part of the k1sendbeacon model (fig.1). I add the EzcaRead block to obtain the value of K1:OMC_TRANS_DCPD_SUM_OUT instead of the RFM. The model was succeeded to complie. 

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takahiro.yamamoto - 23:00 Friday 04 November 2022 (22800) Print this report
Ezca block can get only EPICS channels (probably).
So "OUT16", "OUTPUT" or "OUTMON" must be used instead of "OUT".

And also, channel name is "K1:OMC-" not "K1:OMC_".

Bit mask for COILOUTF is also wrong.
"K1:ETMX_TM" => "K1:VIS-ETMX_TM"
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