How to re-connect a MESSIA optical fiber after the instrument exchange

Introduction

There are two MESSIA fibers connecting the OBCP computer at the computer room and the FOCAS in the dome.

Computer room <- optical fiber -> IR stand-by room
Computer room <- optical fiber -> Telescope CS flange

Since there are no optical hub (such as ether-network hub) is installed, the Messia fiber cable needs to be exchanged (re-connected) according to the FOCAS location in the computer room (on the 2nd floor of the control building) after the instrument exchange (Cs->Standby room, or Standby room->Cs).

The fiber link is established after resetting the Messia board on-board the FOCAS.

Procedure

In the computer room

While the FOCAS is on the standby room:

Connect an orange fiber (with a tag of STBY/FOCAS/Messia) into the FOCAS OBCP computer at its rear panel.

While the FOCAS is at the telescope (Cs flange):

Connect a green fiber (with a tag of Cassegrain/FOCAS/Messia) into the FOCAS OBCP computer at its rear panel.

Note: The FOCAS OBCP computer is located within a computer rack near the far side wall of the computer room, and can be seen from the front computer room door near the main entrance of the building. Since there are several computers with similar appearance, search for the FOCAS computer with care. Some stickers with FOCAS name are hanging around it.

Initialize the fiber communication after re-connecting the fiber

In the dome, move a toggle switch of the Messia VMI on board the FOCAS for re-connection to be completed.
Cycle the toggle switch from on-line (left) to off-line (center) -> reset (right) -> off-line (center) -> on-line (left).
While resetting the toggle (from central position to the right), you need to pull the toggle a little to go over the latch. The toggle automatically goes back to the off-line position (center) after resetting (right).