(privileges may be required)
(privileges may be required)
Instructions for Changing PoPs During the Night
This page has been updated JAN 2020 to reflect the use of the new obsgtks and POPPERIGTK for pop changes. Last update 2-13-23
(The old version can be found by logging into the wiki and selecting the old revisions icon on the right.)
It is proper protocol for the PI's, remote or visiting scientists to announce any PoP changes 10 minutes before needed so the operator can bring up the required windows. Please give the PoP's for only the telescopes that need changing. Use this format: E1-1, E2-2, W1-3, etc. Give the desired PoP only.
1. Check the small “POP Mirror Control Box” next to the troubled pop underneath the delay line rails. (Fig. POP-trouble 1)
2. Slide the CONTROL switch on the box to “Local”. The red “Timeout” LED will most likely turn ON and maybe one of the green ones (Fwd or Rev limit) indicating the current position of the pop. (Fig. POP-trouble 2) Try to use the RESET button: push it with a small enough Allen key. Slide the command switches according to the chart on the box to command the mirror to the other position. 010 moves the pop mirror in, 011 moves the mirror out. Wait about a 30 seconds. If you hear the motor running in the pop can, it is working. If the other green led will come on indicating that the mirror moved, then you are done. It was a simple timeout. Return the CONTROL Switch to Remote and you are done.
Otherwise take the next step.
3. Disconnect all the cables; take the box off the velcro and to a convenient place. Unscrew the four Philips screws at the corners and slowly take off the lid. Do not disconnect the wires inside the box. On the backside of the lid you will see two fuses. Set the meter to continuity mode, which makes a beep when there is continuity, and check the contact between the two ends of each fuse. ( Fig. POP-trouble 3-4 )
A beeping fuse is good. You have to replace the fuse if the meter does not beep. It could be that both of them were blown.
4. This is the type of fuse that you have to use. Look for the cardboard box labeled “Pop Control Box Fuses” in the BC lab. This box now resides at the E1 Pop 1 location.
5. Use tweezers to take out the blown fuse from its holder, and insert a new one. Put the lid back; be mindful of the right orientation with respect to the connectors. (Look at the first picture.) Secure the lid with the screws, and attach the all the connectors.
6. Test the box in “Local” mode. Slide the command switches to FWD: 0 1 0 or REV: 0 1 1 to get the mirror moving and hit the Enter button. Wait until the green limit switch led lights up. When the mirror goes against the hard stops, a clinking sound can be heard from the pop box.
7. If the mirror still does not move as expected further investigation is needed, and probably the pop box has to be opened after letting air into the pipe. If the mirror moved as expected go to the next step.
8. Slide the CONTROL switch to “Remote”. Make sure you did not leave anything on the rail.