Guide Camera Mechanical Controller Commands

• Overview
• Commands
  • <BREAK>
  • FILTER
  • GMECH
  • ID (*)
  • INIT
  • PISTON piston
  • REMAP
  • SET.TIME date (*)
  • STATUS
  • STATUS.LONG (*)
  • STEP.DUMP (*)
  • TIME? (*)
• Status Bits

(*) this command is not used by the TCC

Overview

The guide camera mechanical controller sets the filter, focus and other mechanical functions, but not the position of the guide camera in the focal plane. Positioning, if available, is handled by one or two guider position axes controllers, one per axis of motion.

Commands

Commands marked with (*) are not used by the TCC. They are generally included for use by engineers, or for symmetry with other controllers.

<BREAK>

Hardware resets the controller and halts any motion. See also INIT

FILTER filter_number

Sets the specified filter. Filters numbers are integers, starting at 0. Returns immediately (does not wait for the motion to finish). Leaves the other axes of motion unchanged.

GMECH

Notifies the controller that subsequent commands apply to the guider mechanical controller.

ID (*)

Displays the name of controller and the software version.

INIT

Stops all motion and initializes the internal variables "if necessary".

PISTON piston

Sets the piston of the guider to the specified value (in decimal microns). Returns immediately (does not wait for the motion to finish). Leaves the other axes of motion unchanged

REMAP

Initializes all internal variables, retracts the guide focus to a limit, and resets the position counters to zero. May be interrupted by typing any character, though it may take awhile to respond.

SET.TIME date (*)

Sets the internal clock (optional; not required for proper functioning). Time can be expressed in the normal format (decimal seconds in the day) or in the alternate format: hours minutes seconds (where hours and minutes are integers and seconds is decimal).

STATUS

Returns the state of the hardware and controller in the format:
piston filter time piston_status filter_status
where:

• piston is in decimal um
• filter is an integer
• time is in decimal seconds
• status is a status word, returned in decimal. Click here for details.

Note: The piston positioner has finite resolution, so the requested piston is rounded to the nearest available value. The value returned by STATUS is the actual position, not the position you requested. Also note that the time will be dead wrong unless somebody has bothered to set the clock.

See also STATUS.LONG

STATUS.LONG (*)

Similar to STATUS , but easier for a person to read. The entries are labelled and the status word is given in binary.

STEP.DUMP (*)

Outputs detailed information about each actuator; the values are labelled.

TIME? (*)

Returns the current date. Sample output:
3 5 89 65916.780

Caution: this controller probably does not know the correct time; it is not required for operation and is probably never set.

Status Bits

The status words are 8 bits each. The bits are sticky (they stay on until read, even if the condition has cleared). The bits have the following meaning (preliminary):

0001 limit switch 1 engaged
0002 limit switch 2 engaged
0004 at maximum position
0008 at minimum position
0010 at requested position
0020 actuators powered down
0040 (undefined)
0080 (undefined)

Charles Hull and Russell Owen