SMC Commands

for manually operating the Comparison lamps and the Bench Spectrograph:


Both the comparison lamp system and the bench spectrograph have a GUI which should make their operation easy. However, if for some reason the GUI doesn't work or something is suspect, both systems can be moved manually with a lower level interface which is qcryptic and primitive but is not difficult to use.

To manually control the comparison lamp system you must use the telescope control system by opening a window in the "command mode" and typing your commands in it, preceeded by the word "local". To control the bench spectrograph you have to open a tif window in the Arcon computer and type your commands in there.

If these commands don't work and things don't seem to make sense, try resetting the corresponding "SMC" (Smart Motor Controller).

Both boxes function with the same command syntax:

boxname mechanism action value

Some actions (e.g. init) do not require a value
Some actions (e.g. move) must have a value
Some actions (e.g. status) return a value

Commands must be typed EXACTLY as written when entered manually. The software is not very forgiving. If you make a mistake, type amd start over.

There are three useful General commands, applicable to all boxes.

To reset the box:

[boxname] reset

To make sure the version of software in the box is right:

[boxname] set version

This should always be done after a reset.

To manually turn the motor power on or off and leave it there:

[boxname] (on/off}



The name of the box which controls the comparision lamps is cfadc

cfadc is a peripheral of the tcs. Commands must be passed to the tcs or typed into a command window of the TCS as "local" commands. All manually entered commands must be prefixed by the word "local", e.g.[ local cfadc lamps mov 700 ] .



  1. Mirrors
    There are two mirrors, spherical (sphe) and flat (flat):
    COMMAND: [local] cfadc (flat/sphe) (status/position/move/stop) (in/out)
    BOTH of these mirrors MUST be IN to use the comparison lamp system and OUT to use Hydra.
  2. Arm which carries the Penray lamps (plamps):
    COMMAND: [local] cfadc plamps (status/position/move/stop) (in/out)
    This arm must be IN to use the PenRay lamps and OUT to use the other lamps or Hydra.
  3. There are 5 comparison lamps
  • Etalon (etalon) F-P etalon with lines st 5000A about ~.035A wide spaced at about .86A in order ~5800. Only works from ~4800-8800A. Fairly bright.
  • Th-Ar (tha) Standard Th-Ar:very dim
  • Quartz (qua) Very bright
  • HeNeAr (hene) Standard low intensity HeNeAr lamp: dim
  • PenRay (pen) A set of 4 lamps, He, Ne, Xe and Ar high intensity moved in on a special arm. The combination is designed to approximate the HeNeAr spectrum. The combination of lamps to be used can be selected by switches in the cass cage. There is a switch for each lamp. If all four are on, the "Pen" option will be a HeNeArXe lamp. Selecting HeNeAr produces a lamp with a very different spectrum from the standard HeNeAr lamp because the ionization states and relative intensities are not the same. These lamps are quite bright, especially the Ne.

The first 4 lamps are selected by putting a "lamp" mirror in a numerically identified position with:

COMMAND: [local] cfadc lamps (status/position/init/move) (value)

The best values for the lamp positions are:

etalon 64
tha 241
qua 754

hene 909

The lamps are then turned on or off with


[local] cfadc lamps (etalon/tha/qua/hene/pen) (move/status) (on/off)

 4.  There is a television camera which when activated allows you to see what is going on inside the chimney.

This TV (which contains its own light source) is turned on and off with the command:

[local] cfadc outlet1 move on/off

With this camera, you can tell if the flat and spherical mirrors are in or out and if the quartz lamp is on. The other lamps aren't bright enough.

If you use this camera, be sure to turn it (and its light) off when you are through!

Example 1:

To make a quartz lamp exposure:

[local] cfadc flat move in
[local] cfadc sphe move in
[local] cfadc lamps move 754
[local] cfadc lamps qua move on
[local] cfadc lamps qua status (check position-optional, but a good idea) (should be 754 ~+/-1)

Take exposure:

Turn off comparison system:

Turn off lights
[local] cfadc lamps qua move off
[local] cfadc flat move out
[local] cfadc sphe move out
Check status of everything, if desired
[local] cfadc lamps qua status (returns off)
[local] cfadc flat status (returns out)
[local] cfadc sphe status (returns out))

Example 2:

To make an exposure with the penray lamps:

[local] cfadc flat move in
[local] cfadc sphe move in
[local] cfadc plamps move in
[local] cfadc lamps pen move on

Take exposure:

Turn off comparison system:
[local] cfadc plamps move out
[local] cfadc lamps pen move off
[local] cfadc flat move out
[local] cfadc sphe move out

Check status of everything, if desired
[local] cfadc plamps status (returns out)
[local] cfadc lamps pen status (returns off)
[local] cfadc flat status (returns out) [local] cfadc sphe status (returns out)



The Bench Spectrograph SMC is called bench4m. Commands can be sent manually to the bench4m SMC from the "Terminal" window which can be opened using the spectrograph GUI.

Emergency only! If for some reason the GUI doesn't work, the SMC can also be controlled directly from a tip window. The interface is rather primitive. You must type exactly what is written. Any mistakes will cause the command to be rejected and you have to start over. No back spaces or deletes allowed

Start the tip window from an xterm on the Arcon computer with the following command:

tip ttyb

In the Terminal or (in an emergency only) in a"tip" window, type commands using the following syntax (remember that backspace works in the terminal window, but not using tip)


COMMAND: bench4m mechanism action value

  1. Grating: bench4m grat (status/position/move/stop/init) (0-90[degrees])
  2. Focus: bench4m focus (status/position/move/stop/init) (0-25000[microns])
  3. Filter wheel: bench4m fil (status/position/move/stop/init) (1-4)
  4. Inclination of line of fibers: (removes tilt in spectra)
    bench4m incli (status/position/move/stop/init) ( ~+/- 25.0 degrees)
  5. Led: (Filter wheel must be in position 1 to illuminate fiber)
    bench4m led (intensity/status) (0-255)
    bench4m led move (on/off)
  6. Shutter: The shutter is a disc which rotates in front of the camera. It also serves as the Newall mask. The disc has four positions (in/out/upper/lower). The Newall mask command does not actually move the mask, but sets a flag which tells the shutter how to behave during an exposure. If the Newall mask flag is set to "off", the shutter opens and closes normally. If it is set to "upper" or "lower", the shutter stops in the corresponding position during the exposure.
  7. Newall Mask Flag: This is controlled via the command
    bench4m new (move/status) (upper/lower/off)

The shutter is normally under Arcon control. In this mode, it remains closed until Arcon tells it to open and then stays open (or partially open according to the state of the Newall mask flag) until the exposure has ended and then rotates back to closed. The shutter disc can also be controlled directly from the smc.

bench4m shu control arcon [transfers open/closed control to Arcon]

(The box comes up in "smc" mode so this command must be issued after any reset before any exposures can be taken.)

bench4m shu control smc [transfers control to direct mode]

To move the shutter manually in direct mode, one must send it to specific numbered positions:

open = 100
close = 20600
upper = 2400
lower = 3100

using the command

bench4m shu (move/init/stop/status) #position


bench4m shu control smc
bench4m shu move 100

manually opens the shutter.

If you move the shutter manually it should be manually closed before returning control to Arcon. Returning control does not automatically close it.


T. Ingerson

Last update:
22 June 1999-tei
13 August 1999 -tei
20 May 2000 - tei
2 August 2000 - tei
27 October 2000 - tei