Honeywell BR3C9 Operation Manual page 23

2-2
Control or Indicator
CHECK
switch/indicator
POSITIONER OFFSET
switch
READ CLOCK switch
TABLE 2-1. CONTROLS AND INDICATORS (CONTrD)
Function
Operator Panel (Cont'd)
Lights when one or more of the following fault conditions
occur.
• .Read or write
is
commanded without an On Cylinder
siqnal.
• Low
voltage (±Sv, ±20v, or -16v) condition
• Read and Write commanded at
the
same time
• Servo dibits lost for more than 200 ms
• More
than
one head selected
• Air flow has decreased below an acceptable limit
• Head register contains number exceeding 18
(no
head select)
• Write command without write current
• Write CUrrent without Write command
Logic Chassis Maintenance Panel
NOTE
The POSITIONER OFFSET and READ CLOCX switches
are designed for use during a maintenance
situation. Functions of the two switches are
enabled only when the ONLINE switch. is set to
either OF? LINE position.
NORMAL position allows servo logic to position positioner
to the nominal center of the disk pack servo recording
track.
OOT position injects a fixed bias so that positioner
is positioned 400 micro inches off nominal center of
servo track in the direction away from the spindle.
IN position injects a fixed bias so that carriage is
positioned
400
microinches off nominal center of servo
track in the direction toward the spindle.
NORMAL position allows read data strobe to occur in the
nominal center of the allowable margin of the data
window (time period in which a recovered data "1" must
appear in order to be recognized as a "l").
AOV position causes data strobe to be moved to the
advanced (early) marqin position of the data window.
(Data strobe occurs about 8 nanoseconds earlier than
nominal) •
RET position causes data strobe to be moved to the
retarded (late) margin position of the data window.
(Data strobe occurs about 8 nanoseconds later than
nominal. )
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