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JoshuaWilliams - 30 Apr 2020
Raise Primary Mirrors / Recovering from Primary Mirror Panic
Auth: Josh Williams
v1.0 April 29th, 2020
**You’ll first want to bring the telescope to zenith prior to raising a mirror.**
**Do NOT try to raise the primary mirrors while telescope is at horizon.**
(The mirror can raise at any elevation, but cannot raise while the elevation is changing. It is faster to raise the mirror while parked at zenith.)
If raising the M1 due to a mirror panic, in the appropriate (Left/Right) Primary Mirror Cell GUI (PMCL/PMCR), first click on
Recover Panic.
Click on
All Air On to start raising air pressure.
While air pressure is being raised, in the PMCL/PMCR GUI, click on
Air Pressure to bring up the
PMC Air Loops Status and Control subGUI.
From
PMC Air Loops Status and Control subGUI, you should keep an eye on all air loops (Blue-1, Green-2, etc.), until they reach a value between 100 & 120.
Once the air loop values are stable between 100 & 120, from the PMCL/PMCR GUI, click on
Auto-Raise to start raising the primary mirror again, then click on
Hardpoints to bring up the
Hardpoints Status and Control subGUI.
From the
Hardpoints Status and Control subGUI, you should keep an eye on the load cell values, as they go from >500 to ~0, and eventually the limits all read “OK”.
While the mirror is being raised, from PMCL/PMCR, click on
Actuators to bring up the
Actuators Status and Control subGUI.
From the
PMC Actuators Status and Control subGUI, click on
Enable All to enable all actuators. You should see all disabled actuators in the “Disabled” box eventually disappear.
From the PMCL/PMCR GUI, you should watch the weight return to 100%, and Chase state become “Idle”.
If a mirror panic happens during night observations, in the PMCL/PMCR GUI, click on
Collimate. This isn’t necessary, but it can save time. The primary mirror is now ready.
Tips & tricks
If the air pressure doesn’t want to come on when you first press
All Air On in PMCL/PMCR, you can check the status of the air compressors (
AC) from
Environmental Control Subsystem GUI (ECS) to make sure they’re on.
Lowering Primary Mirrors
In the (Left/Right) Primary Mirror Cell GUI, click on
Auto-Lower.
- Wait for 0% in Weight section and “Auto-lower complete” in log.
- In Air Control section, click on All Air Off.
- Wait for “Complete” message in log.