PS-MOD-073 · r3 MODE TRANSITION OBSERVED ENGAGED

MODE-BOUND CONTROL MAPPING

The hand remembers the control. The control has changed what it does.

01 DEFINITION

Condition in which one control carries a different function depending on the mode in force, so a movement practised until it no longer needs thought is correct in one mode and is something else in another, with nothing in the movement itself to tell them apart.

02 CONDITIONS

UNCERTAINTY MISSING Which mode is in force is not available to the hand at the moment the hand moves.

TIME PRESSURE SHORT The movement is quick and practised; that is the whole reason it is not checked.

ERROR ASYMMETRY ASYMMETRIC The functions sharing the control do not cost the same when the wrong one is invoked.

OPERATOR STATE DEDICATED The person is operating and the movement is below the level they are attending to.

03 WHERE IT APPEARS

MEDICALOne key on a device commits to different things depending on the programme running, and the hand does not check which.

MOBILITYA stalk or wheel control acts differently by drive mode, and the driver reaches for it without looking.

INDUSTRIALA consolidated panel gives one button several duties selected by a setting made earlier.

MANUFACTURINGA pendant control means one thing in setup and another in run, and the movement is the same.

ENERGYA control point on a shared console changes what it commands with the view that is loaded.

CONSTRUCTIONA lever on plant equipment serves different functions by mode, reached for by feel.

04 WHAT AEON WORKED THROUGH HERE

Consolidating the panel meant one control now did several things, and which one depended on a mode set some minutes earlier. The movement had been practised past the point of thinking about it, and thinking about it was exactly what the new arrangement asked for at the moment there was least room to. The work went into which functions may share a control at all, so that the ones whose confusion could not be afforded did not.

What stays unresolved is how a mode announces itself to the hand rather than to the eye — a change shown only on the surface is one the practised movement will not stop to consult, and a change felt in the control has to be built into every control that can change.

05 LINKED TERMS

PS-MOD-063 MODE CONFUSION PS-MOD-072 STATE MEMORY ACROSS MODES PS-MOD-075 NESTED MODE DEPTH PS-INP-155 CONTROL PATH DIVERGENCE PS-INP-162 REACH AND READ SPLIT PS-INP-169 BLIND OPERATION LOST PS-MOD-182 STATION OUTLIVES MACHINE