48 lines
1.4 KiB
Plaintext
48 lines
1.4 KiB
Plaintext
Take a six circle diffractometer with angles:
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delta, nu, mu, eta, chi, phi
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and virtual angles:
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qaz, naz, psi, alpha, beta.
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Many combinations of these can be constrained:
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constrain
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>>> con nu
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>>> con psi
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>>> con mu
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>>> con nu mu a_eq_b
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real angles are always constrained to there last set position. If they are too far from here
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an error will result.
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>>> pos nu 0 (moves, parameter tracks last set value (actually checks it when hkl moved))
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>>> pos psi 90 (does not move, sets parameter in diffcalc)
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>>> pos mu 0 (moves)
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>>> pos hkl [1 0 0] (moves based on last set nu, psi, mu)
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>>> pos betain --> Exception, not constrained
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moving a virtual angle simply sets it to efftec the next hkl move
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Here we need onlu con, uncon and pos.
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......
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However it would be nice to be able to pos betain for example and have it change
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betain while staying on the same reflection. This might be enabled by locking the
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the current hkl position. It would be trick to make this work with the physical angles though.
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>>> lock hkl
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>>> pos psi 90 (moves immediately)
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>>> scan psi 0 90 1 (scans, moving immediately)
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>>> pos mu 0 (does not move immediately) (could work by listening to target positions, and triggering move when complete)
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>>> pos c(mu) moves
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>>> pos mu_c moves
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Only one thing would be varyable at a time unless they are put in a CoordinatedMotionGroup,
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which would be hard for the real motors)
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