(Joe, Yuta)
Summary:
We found some mistakes in whitening filter switches yesterday(see elog #3748).
One was the mis-connection between LL/LR and the second was the bit invert.
So, we fixed it and checked that they are now switching correct by probing MAX333A.
Why we made mistake:
1. LL/LR mis-connection
Simply, Simulink model was wrong.
It occurred because UL/UR/LR/LL order is currently arbitrary and confusing.
For now, we just swap the connection(Attached #1).
In the future, we should fix all orders corresponding to the actual wiring order(UL > LL > UR > LR).
2. Bit invert
It occurred from counter-intuitive output of Contec 32 BO(See Attachment #2(taken from this wiki page)).
If "1," current goes from A to B, so MAX333A input will be 0V, which means analog WF is on.
If "0," no current, so MAX333A input will be +15V, which means analog WF is off(bypassed).
Next work:
- There are no digital WF in SDSEN inputs. So, we have to put them.
- Dewhitening filters are totally messed up now. Switches are wrong, some optics have digital DW but some doesn't, some have 28Hz elliptic LPF.......
We have to grand unify them. |