40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Fri Jun 27 12:54:13 2014, Akhil, Update, Electronics, Gain plots of UFC-6000 for 0.1s Sampling Rate  Sampling-0.1s.pdf12.png
    Reply  Tue Jul 1 21:20:37 2014, Akhil, Update, Electronics, Gain plots of UFC-6000 for 0.1s Sampling Rate  gain.pnggain.pdf
Message ID: 10107     Entry time: Fri Jun 27 12:54:13 2014     Reply to this: 10118
Author: Akhil 
Type: Update 
Category: Electronics 
Subject: Gain plots of UFC-6000 for 0.1s Sampling Rate  

 Finally, the 0.1s sampling rate of the frequency counter(FC) has been achieved. For this I had to :

 Send in byte codes to set a particular range of the frequency counter.

I was digging  in to find how exactly the circuit inside the frequency counter works and how the processor inside is able to read and write bytes through a HID-USB interface. I found out that the 'AutoRange' setting (which I have been using so far) has an independent  multiplexing circuit  which consumes some time(that varies with the drift in frequencies) and thus, the the processor waits for some specific time for this process and cannot reach the minimum 0.1 s sampling time. To mitigate this issue, I set the range bytes to the appropriate range of frequencies so that I can bypass the MUX  delay. Here is the list of Range and frequencies for the FC:

Range 1:    1 - 40 MHz

Range 2:    40 - 190 MHz

Range 3:    190 - 1400 MHz

Range 4 :   1400 - 6000 MHz

I then took measurements for sampling time of 0.1 s at carrier frequencies of 5 MHz and 25 MHz from SRS DS345  and plotted the improvised gain plots(attached) to those in my previous elog(10070)  with the same procedure mentioned before.

 

To do Next:

Plot the gain plots for higher carrier frequencies till range 3 using Marconi Function generator.

Write the data from FC into C1: ALS-Y_SLOW_SERVO1_OFFSET EPICS channel.

 

 

Attachment 1: Sampling-0.1s.pdf  6 kB  | Hide | Hide all
Sampling-0.1s.pdf
Attachment 2: 12.png  11 kB  Uploaded Sun Jun 29 15:42:40 2014  | Hide | Hide all
12.png
ELOG V3.1.3-