OTTER is the name of the program that is used to control the receiver selection on the 26m telescope. There are two components - a server and client. The server accepts TCP connections and talks to the hardware while the client is a GUI that provides information on the current status.
To start the GUI, run
The list of available commands is listed in the lower section of the GUI. The commands are entered by typing the character in the square brackets and pressing enter e.g to select the 8.4 GHz receiver, type
Selecting a receiver
Always make sure that the telescope is parked before changing receivers. Otherwise, there’s a serious risk of damage if cabling gets caught on the platform as it moves.
Check that the display in rack 3 shows the selected receiver number after a second or so. If you’ve changed from one receiver to another, the focus platform should start moving to the new focus position. If it does not, try toggling the switch above the Rx display from “Auto” to “Manual” and back again.
If you can’t change a receiver (after a power failure say), type “r” to reset the electronics in the focus cabin.
Using the Quadrature Hybrid & crossover switch
For most experiments (except at L-band) you should have the Quadrature Hybrid OUT (indicated by the
Checking cryogenic status
If everything is working, the multifeed 70K/20K readings should be ~60/30 and the L-band 70K/20K readings should be ~80/35. If any of the readings are more than ~10 degrees above these nominal values, it may indicate an impending problem. Getting in early saves a lot of time overall, so please let Brett and Eric know about this as soon as possible.
The OTTER server runs on rx26m. If the GUI fails to start or returns error messages, please check that it is running (with