Fil, Keita, Dave, Patrick, Rahul

Today morning Fil went to the CER room once again and continued with his investigation to see if it is a driver or a DAC issue in Ham2 suspensions. To test this, Fil requested me the following settings on MC1 and MC3 coil output filter (based on Keita's alog 57151),

(1) Turn off damping as well as alignment offset of MC1 and MC3, (2) Put the driver to state 2, (3) Enable 5000 counts offset for all of individual coils of MC1 and MC3 top coils e.g.  H1:SUS-MC3_M1_COILOUTF_T1_OFFSET.

His measurements showed that there were some issue in the AI chassis to coil driver (output was low) for MC3 T3 coil, which was then replaced.

After the AI chassis was replaced, Keita asked me check the voltmon for MC1, MC3, PRM, PR3 - m1, m2 and m3 coils (total 14 coil output filters per suspension). I set the offset (on Coil Output Filters) to 5000 and looked into the ndscope for the voltmon (in H1SUSMC1 Aux Ch medm - within MC1 medm screen). Please find the results attached below. The results shows that for m1 coils, all of the voltmon shows about 250 counts/5000offset value and for the m2/m3 coils it is around 450 count/5000offset value (some offset were set to 10000 to check for saturations). Keita was satisfied with these numbers. Next, I switched OFF all the offsets, switched ON the top mass damping and set the GRD to the following state (this resulted in some change in the voltmon values which is also reflected in the plots),

MC1 - ALIGNED,                MC3 - MISALIGNED,

PRM - MISALIGNED,         PR3 - ALIGNED

Final conclusions - now everything looks healthy in the HAM2 suspensions. Keita will also write his conclusions in another alog.