NAOJ GW Elog Logbook 3.2
Participants: Matteo Tacca, Eleonora
Today we moved the BS suspension in order to have the reflecting surface of the mirror 10 cm south with respect to the center of the chamber, according to the telescope design.
We have also installed the fixed mirror support and connected the in-vacuum and out-of-vacuum cable to move the picomotors. We had some issues in moving the pitch and the translation picomotors in one direction (the other direction works fine).
The picomotors seems to receve signals from the drivers since they make a noise but most of the time they don't move and sometimes they move very slowly.
NB: Ony few days ago I I have checked that the 3 picomotors can work in both directions (entry 420)
We made many checks in order to find out the cause problem:
1) We checked carefully all the connections in and out of the vacuum chamber. They were all fine.
2) We changed the picomotor with a spare one but it didn't solved the problem. So it is not a problem of the picomotor itself.
3) We have tried to control them by PC using labview: nothing changed.
4) We have changed the pad of the driver: nothing changed.
5) We have changed the slot at which the cable was connected in the driver: nothing changed.
6) We have inverted the pins of pitch and yaw in the in vacuum connector and this time the pitch was working fine in both directions while the yaw was now showing the issue.
This last test made as to suspect the driver which, by the way, showed some other problems ( i.e the knob to change the controlled slot gets often stuck and it is necessary to switch it on and off).
I found a similar driver in the instrument shelf at the first flor but it didn't switch on.
Tomorrow we will:
1) Check the driver on other picomors, as those of the PR suspension which were also succesfully tested before.
2) Look for other GPIB picomotor drivers in TAMA. (NB according to their label these drivers have been bought in 1999)