Hoher List 1m Telescope Control System


1m telescope The telescope system is made up of
The control of the whole system is based on a single Linux PC and a large number of  microcontroller modules that perform basic operations (like "position dome" or "open dome slit") . These modules and the control PC are interconnected - in a distributed system approach - by  the popular and very robust CAN (Control Area Network) field bus. Thus they form the Telescope Control Network. Most of these modules are actually located in the Telescope Control Cabinet.

The telescope control software (HOLICS 2) running on the Linuc PC is accessed by the observer usually through a terminal window at the data workstation "becker" in the observers room.

Telescope system components the obsever may have to interact with:

In the dome:

Telescope Control Cabinet
 telescope cabinet
its main panel
cabinet panel  
and its real heart
The Telescope Control Cabinet main power switch is at the left hand side of the cabinet. 
The cabinet front panel allows to control manually
  • dome rotation, 
  • dome slit, 
  • telescope focus, 
  • M1 cover 
  • oil pump (on/off)
  • a set of 230V connectors at the mirror cell (on/off)
and to switch between manual and automatic control.
The red LEDs in a column indicate error conditons. If one of these errors occurs telescope motion stops immediately.
  • oil pressure to low
  • hour angle limit switch east and west
  • low elevation limit switch
  • declination limit switch
  • fork limit switch (the focal reducer doesn't go trough the telescope fork).
  • Software enable (used by the HOLICS control program to stop the telescope immediately)
In some very rare cases (e.g. telescope hits limit switch) the large aluminum plate has to be removed (2 knurled-head screws) to allow access to the real heart of the cabinet.
The handset differs from the classical telescope handset in that it is an independant device in the Telescope Control Network. It communicates not only with the control PC but also with any other micro controller module (e.g. to move the dome). It does have a display, cursor and a set of function buttons. The display is fed by the PC (with position information). The function buttons are for dome control etc.. For a detailed description see below.
The joybox is used by the observer only in case the control program fails, e.g. to move the telescope to encoder reference positions. The cursor buttons of the joybox move the telescope in hour angle and declination. The box is directly connected to the Lenze motor control unit. To get it activatetd the mode switches at the Lenze motor control board have to be set to "Hand" (i.e. manual).
Flat-filed lamp power supply
flat-filed lamp PS

Emergency switch
notaus dome
When pressed telescope motions will be stopped immediately . The red button has to be pulled back to be deactivated.

In the observers room

HOLICS terminal window  at  the Linux workstation "becker".
The telescope control program HOLICS (running on the dedicated telescope control PC in the HOLICS room) is started with the HOLICS icon and runs in a terminal window.  The user interface is still text based. All operations are initiated by pressing a key which is interpreted as a function key.
Weather PC (under construction)
This PC is connected to the weather monitoring station and the rain sensor at the distant edge of the laboratory building.
Rain buzzer and flash light (under construction)
This is triggered by the rain sensor. In case of rain also the dome slit shall close automatically. The decision when to reopen after rainfall has stoped is up to the observer.

In the HOLICS room

Telescope control PC (HOLICS PC)
Linux PC running the main telescope control program. The program is usually started from the "becker" PC in the observers room and runs there in a terminal window. It can also be started and run from here. (login as usual "ccd/dig_lab" and hit the HOLICS icon).
A second PC exists as backup system.
"Lenze" telescope motor control unit board
lenze motor control
Each of the two telescope drive motors  has its own control unit: Ha - left, Dec - right.
  • Above the Lenze control units are the individual main power switches.
  • Below the control units is the mode switch and resolver reset box with two black mode switches and two locks. The mode switches have three positions.
    • Auto: Normal position during observations. TheTelescope control program controls the telescope motions.
    • 0: Telescop motion control is completely deactivated.
    • Hand: Manual control of the telescope with the Joybox is activated. The telescope control program can still drive the motors.
  • The two locks (upper - Ha, lower - Dec) are used to reset the telescope motor resolvers (low precision position encoders). This is necessary only in case of  a telescope encoder reset (in case of trouble with positioning/tracking). To reset use on of the keys. Turn clockwise and back again. To avoid accidental resets remove the key after reset.
UPS (uninterruptible power supply)
This UPS supports only the telescope control PC. The main purpose is to prevent loss of  telescope status and position information during power failure (ca. 30min max.). Usually the observers isn't concerned with this device. Here it is shown for completeness.
Telescope focus control unit (under construction)
This has a reset button that has to be pressed by the observer when a telescope focus reset becomes necessary (e.g.. in case the focus position encoder - the famous SONY  - fails).
Emergency switch
When pressed telescope motions will be stopped immediately. The red button has to be pulled back to be deactivated.