Rana Systems Elite Series - Manual (Page 159)

ELITE SERIES USER MANUAL SPECIFICATIONS
Although a newly selected drive will not return
valid data until the motor comes up to speed,
the software need not incorporate any timing
delays before attempting a read provided the
motor-on time is taken into account in any retry
logic. Since a 500ms motor-on time is a maximum,
the system software can usually shorten the
delay by sampling the drive’s returned data
until valid data begins to appear.
Stepper Motor Phase Selection
In order to move the read/write head, each of
the four phases of the stepper motor (A-D) must
be turned on then off again in a certain se-
quence. Each phase is activated/deactivated in
direct response to the stepper motor p~ase con-
trol interface signals being set logically
high/low respectively. If the stepper motor
phases are activated then deactivated in ascend-
ing order (A, B, C, D, A, etc), the arm is moved
inward. In descending order (A, D, C, B, A,
etc), the arm is moved outward. The timing be-
tween activation and deactivation of these sig-
nals is critical.
Activate Writing
The active state of this signal, or logical low,
enables the write data to be written on the
diskette. The inactive state, or logical high,
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