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Entry  Sat Jul 26 10:12:19 2014, Akhil, Update, General, Data Acquisition from FC into EPICS Channels 
    Reply  Sat Jul 26 13:38:34 2014, Jamie, Update, General, Data Acquisition from FC into EPICS Channels 
       Reply  Sat Jul 26 14:35:28 2014, Akhil, Update, General, Data Acquisition from FC into EPICS Channels 
Message ID: 10274     Entry time: Sat Jul 26 10:12:19 2014     Reply to this: 10276
Author: Akhil 
Type: Update 
Category: General 
Subject: Data Acquisition from FC into EPICS Channels 

 I succeeded in creating a new channel access server hosted on domenica ( R Pi) for continuous data acquisition from the FC into  accessible channels. For this I have written a ctypes interface between EPICS and the C interface code to write data into the channels. The channels which I created are:

C1:ALS-X-BEAT-NOTE-FREQ

C1:ALS-Y-BEAT-NOTE-FREQ

 

The scripts I have written for this can be found in:

db script in:     /users/akhil/fcreadoutIoc/fcreadoutApp/Db/fcreadout.db

 Python code:  /users/akhil/fcreadoutIoc/pycall

C code:          /users/akhil/fcreadoutIoc/FCinterfaceCcode.c

I will give the standard channel names(similar to the names on the channel root)once the testing is completed and confirm that data from FC is consistent with the C code readout. Once ready I will run the code forever so that both the server and data acquisition are in process always.

Yesterday, when I set out to test the channel, I faced few serious issues in booting the raspberry pi. However, I have backed up the files on the Pi and will try to debug the issue very soon( I will test with Eric Q's R Pi).

To run these codes one must be root ( sudo python pycall, sudo ./FCinterfaceCcode)  because the HID- devices can be written to only by the root(should look into solving this issue). 

Instructions for Installation of EPICS, and how to create channel server on Pi will be described in detail in 40m Wiki ( FOLL page).

 

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