Princeton FA-448 User Manual

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IV. O p e r a t i o n
A.  Remote Operation from Controller Unit
The filter positions of each filter wheel can be controlled using the thumbwheel switches on the 
controller modules supplied with the filter assemblies.  Connect the motor drive cable of the 
controller to the motor connector of the filter wheel for each unit.  Connect the control unit to an AC
line of the voltage listed on the back of the controller. The positions 0 - 6 may then be selected by
this switch.
B.  Operation with RS-232 Computer or Terminal
Connect the motor drive of the control unit to the filter wheel and the RS-232 output of the control
unit to an RS-232 port of a computer or terminal.  See section III-B for cable installation instructions.
The filter wheel with controller responds to commands from the computer or terminal in the form of
ASCII strings.  The following two commands are used for controlling the filter position:
FILTER 
Controls the filter position and is used as follows:
3 FILTER <enter> sets filter wheel to position 3.  Filter 
positions 1 - 6 may be selected.  Note that there must be a 
after the number and the command must be terminated 
with the enter or carriage return key. The filter will go 
to the specified position in the direction which 
requires the shortest move.  When the move is 
complete, the controller will respond with OK followed 
by carriage return and line feed (hex AXCII sequence 
20 6F 6B of OA).  Also, the default condition is to echo each 
character that is sent to the controller.  If no echo is 
desired, the command NO-ECHO will suppress the echo.  
The command ECHO will return the controller to the 
default echo state.
?FILTER
Returns the current filter position.  Typing ?FILTER <enter>
will cause the current filter position to be returned to the 
computer and displayed.
FHOME
Initializes the filter wheel to the first filter position.  
This command is automatically executed at power-up.  
The filter wheel controller keeps track of filter 
position as long as power is applied.  It should not be 
necessary to execute this command under normal 
circumstances, although it is available if desired.  This 
command follows the same format as in FILTER above 
for entry and response.
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