SupaSlim Filter Wheel
Control Protocol
Introductory Notes
The True Technology SupaSlim Wheel is designed to 'auto-learn' any of the four different types of internal disk that could be installed at the time (5 x 72°, 6 x 60°, 7 x 51.4° or 8 x 45°). To do this an 'initialise' sequence must first be sent from the PC and on the standard software provided this is the 'Home-Learn' command (see menu in User-Manual). On receipt of this command the SupaSlim Wheel will run up to one complete cycle and on detecting the 'Home' position will then run a further distance to determine the disk type, before returning to the 'Home' position, which is always Filter Number 1 position. At this point the Wheel will signal a response to the PC which lets it know which type of wheel is installed. The PC knows that the SupaSlim Wheel will be in Filter Number one position, so it is not necessary for the SupaSlim Wheel to send positional data after the learn sequence.
The command structure below should be sufficient for users to integrate into their own software, to control the SupaSlim Wheel.
Note that in addition to commanding the SupaSlim Wheel directly, the PC can query the current position of a filter wheel.
Note that an optional Field Hand Unit is available. The FHU simulates the PC operation, operating over the same serial interface, (mutually exclusive).
Software integrators will presumably 'save on exit' the previous status (wheel-type and position), so that if they are using the same wheel as before, without changing position then on powering up the PC the s/w will default to the correct state.
A stand-alone EXE control program is available as a download from the True Technology website, and this will be updated from time to time to reflect any changes or enhancements to the SupaSlim Wheel.
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Protocol Details:
RS232 9600 8,N,1 OK
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Reset wheel and learn size message from PC
SOM A5h
Type 03h
filler 20h
chksum sum of 8 bit additions above = C8h
Response from filter wheel
SOM A5h
Type 83h
Wheel size 06h (could be 05h, 07h or 08h)
checksum 2Eh
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Set Filter position message from PC
SOM A5h
Type 01h
Number 05h for filter 5
chksum sum of 8 bit additions above = ABh
Response from filter wheel
SOM A5h
Type 81h
Number 05h for filter 5
chksum 2Bh
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Query Message from PC
SOM A5h
Type 02h
filler 20h
chksum sum of 8 bit additions above = C7h
Response to query from filter wheel
SOM A5h
Type 82h
response 35h * see table below
chksum 88h
response codes
30h = in motion
31h - 38h = filter positions if located
41h - 48h = error codes.
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Copyright 2000
True Technology Ltd
Woodpecker Cottage
Aldermaston
Berks, RG7 4PA
e-mail: info@trutek-uk.com
Tel: [44] (0)1189 700 777
Fax: [44] (0)1189 701 031
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