TEL_CONTROL command description

Tel_Control is a task which runs on the instrument VAX 4000 to allow

external computers to interface to the telescope control computer (CCS)

via a simple RS-232 line. It accepts simple ASCII commands, provides

validation, then relays the necessary commands to the CCS (via the

CAMAC IPL). It monitors the telescope and reports success/failure to

the requesting computer system.

It has been used by the ADFA MIRAS/NIMPOL system to provide telescope

coordinates and accurate timing, and the Japanese PICNIC IR camera to

perform mosaic imaging. Only a few commands are currently offered, but

new options can be added as required.

Commands:

Commands may be upper or lower case (or any mixture) but the command

line must be terminated by a line feed character (hex 0A). Most terminal

lines will allow termination by a carriage return/line feed combination.

The terminal characteristics to be set are:

9600 baud

8 bits

1 stop bit

no parity

but can be changed if necessary.

Alternate commands are sometimes available to conform to the ANU 2.3-m

control system. Command parameters are free format, i.e. leading

zeroes may be omitted, spaces are ignored, signs are assumed positive.

The full command name must be entered. Commands are:-

WHERE or PLEASE

enquire telescope coordinates and time. Returns the string:

HH MM SS.S #DD MM SS EEEE.E #HH MM SS.S AA.AAAA HH MM SS HH MM SS

which is the RA, Dec, equinox, Hour angle, and airmass of

the telescope, and UT and ST as read from the AAT master clock.

SLEW or TRACK/CO/WAIT hh mm ss.s #dd mm ss eeee.e #pmra #pmdec

Slew to absolute coordinates. Equinox defaults to B1950

and proper motions to 0.

Returns the string "TEL$" once the telescope arrives.

OFFSET/SL/WAIT #ra_offset #dec_offset

Offset the telescope from its current position by

ra_offset, dec_offset arcseconds. North and East are

positive. No allowance is made for sec(dec).

Returns the string "TEL$" once the telescope arrives.

OFFSET #ra_offset #dec_offset

Offset the telescope FROM BASE POSITION by ra_offset,

dec_offset arcseconds. North and East are positive.

No allowance is made for sec(dec).

Returns the string "TEL$" once the telescope arrives.

FREEZE Freezes the (cassegrain) autoguider.

Returns the string "TEL$" to confirm state.

THAW Thaws the (cassegrain) autoguider.

Returns the string "TEL$" to confirm state.

ZENITH

Slews the telescope to zenith park.

Returns the string "TEL$" once the telescope arrives.

AXIS axis Set the telescope to the selected axis (where axis is 0, 1

or 2 for "A", "B" or "Ref"). (Does not lock out night assistant.)

Returns the string "TEL$" to confirm action.

FOCUS_GET Get current telescope focus. Returns focus value string.

FOCUS n Set current telescope focus to n (0 >= n <= 99.99mm).

Does not set (or reset) the base focus.

Returns the string "TEL$" once desired focus is set.

FOCUS_MARK Adopt current focus position as "base" focus, sets any

offset to zero.

Returns the string "TEL$" to confirm action.

Note: sending a new FOCUS_MARK forces the current focus

to be the base focus and set FOCUS_OFFSET to zero.

FOCUS_OFFSET n Move focus to (base + n). Must have done a FOCUS_MARK first.

Returns the string "TEL$" once desired focus is set.

END or GOODBYE

end session and terminate program

Errors:

All input is validated and any errors are reported. Additionally, some

errors are reported from the telescope and timeouts have been set for the

completion of some commnds. Error messages take the form of the string

ERROR!

and followed by a descriptive string which the calling program should

report to the user. The current list of error messages is:-

ERROR! Unknown command.

ERROR! Failed to get telescope coordinates.

ERROR! Star data incorrect.

ERROR! Telescope slew failed.

ERROR! Timeout waiting for telescope to slew.

ERROR! Timeout during telescope slew.

ERROR! Timeout waiting for dome.

ERROR! Invalid offset/sl/wait parameter.

ERROR! Offset/sl/wait failed.

ERROR! Invalid offset parameter.

ERROR! Offset failed.

ERROR! Failed to send telescope to zenith.

ERROR! Timeout waiting for telescope to park.

ERROR! Failed to FREEZE autoguider.

ERROR! Failed to THAW autoguider.

ERROR! Failed to select axis.

ERROR! Don't understand AXIS data.

ERROR! Failed to get telescope focus.

ERROR! Failed to set telescope base focus.

ERROR! Invalid FOCUS value.

ERROR! failed to set FOCUS.

ERROR! FOCUS not in computer control.

ERROR! Timeout waiting for focus.

ERROR! No base FOCUS set.

ERROR! Invalid FOCUS OFFSET value.