Lucia, Yoshinori,

= ITMX =
We tried to correct the driving matrix for the IP, since in the transfer functions which were measured with the previously calculated matrix, the phase was flipped, even thought the diagonalization performance was good indeed.

== What we did ==
-- First, we tried the measurement/calculation again with the following procedure (more detailed procedure is summarized in klog#6118):
  -- send 2Hz sinusoidal signal from each coil, and then measure the LVDT signal in L/T/Y, and used the transfer functions like IP_DAMP_L_IN / IP_COILOUTF_H1_OUT. (So far we were using IP_DAMP_L_IN / IP_COILOUTF_H1_EXC since *I* thought this was the cause of this issue.)

Then we found that the procedure with (IP_DAMP_L_IN / IP_COILOUTF_H1_EXC), i.e., the original procedure made sense indeed. But instead, the signs of (either sensing matrix or) COILOUTF-gain was to be corrected; Originally, we set the sign(+/-) of COILOUTF-gain so that the LVDTINF_OUT_H* signal went to + direction when + signal was inserted to COILOUTF-OFFSET. However, this frame seemed to have opposite sign compared with the frame which was used after this diagonalization work.

== Next ==
-- Check the frame used in the calculation again
-- After confirming the sensing matrices are correct, (and if this is yes) we will change the sign of COILOUTF-gain.


Lucia,
    Can you send me a figure about the frame of ITMX/ETMX/SR3 which you (and your company) were using in the diagonalization work? I would like to summarize the information into a figure. What I want to have is like the attached, please let me know in an email. About the diagonalization work mentioned in the above, I will let you know in the coming week again with more words; your method for driving matrices looked correct, the issue seemed to be caused by the other part.
    And one thing, more in general:
It would be great for us to propose what we want to do in the coming week at the end of every week like Friday: proposing about when/how long do we want to do our measurement (including for what). Otherwise we will not be able to start any discussion about arranging the time slot for the the measurements. Can you please write your next-week's plan into a page under the VIS wiki page if you agree with this? I will make the page and let you know where the page is within this weekend.
We can insist at the pubilic space more, not between us!
Sincerely,