;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
;
;*NAME:                 pics_filt_xchng
;
;*CATEGORY:             PMAS Instrument Control Software
;
;*PURPOSE:              A&G Camera filter exchange procedure
;                       with some safety considerations
;
;*CALLING SEQUENCE:     pics_filt_xchng,e
;             or:       pics_filt_xchng,e,/VERSION   to retrieve Version No.   
;
;*PARAMETERS
;             input:    none
;
;            output:    e = Version String   
;
;          Keywords:    none
;
;*EXAMPLES:             pics_filt_xchng,e
;
;*SYSTEM VARIABLES USED:
;
;*COMMON BLOCKS:        picsDataBase 
;
;*INTERACTIVE INPUT:    - password
;                       - manual entry of filter names
;
;*SUBROUTINES CALLED:
;
;*FILES USED:
;
;*SIDE EFFECTS:         Critical situations may arise upon
;                       re-init of Grating Rotator during the mechanical
;                       exchange process. Operator must make sure there
;                       is no one interfering with the ongoing procedure. 
;
;*RESTRICTIONS:
;
;*NOTES:
;
;*PROCEDURE:
;
;*MODIFICATION HISTORY: 
pmas_filt_xchng_VERSION = 'pmas_filt_xchng.pro Version 1.0 --- 26/08/02 mmr'
;
;	26/08/02	MMR	initial programming
;          
;*AUTHORS:
;
;	MMR		Martin M. Roth	Astrophysikalisches Institut Potsdam
;					An der Sternwarte 16
;					D-14547 Potsdam  
;					Tel. +49 - 331 - 7499 313
;                                       email: mmroth@aip.de
;-