IBM 727, Руководство по инструкции

Страница: 88 / 163

22-6 (09.03)
Latch trip the tape break relay when unloading after a tape
break.
22-7 (09.04)
22-8 (09.06)
Drop R2 if the unload button is pressed during load rewind.
If a condition existed where the capstans were extended while
in unload status, the capstans would automatically be r e ­
tracted. R22-8 runs the capstan motor while the capstans
are being retracted.
R12, DP3, High-speed
rewind motor (09. 05)
It is picked during high-speed rewind when all conditions
are met to actually start moving tape (capstans in, tape
out of both columns, head cover up). R12 and DP3 drop
when the reel arm switch makes.
12AL, BL (10.01)
12BU (09.05)
Remove 1/2 power to both stop clutches.
Turn off the take-up motor (starting a high-speed rewind
from a loaded condition) when tape is out of the columns.
R13, Clutch transfer
(09.06)
It is picked when unloading, while unloaded, and during
load rewind until both capstans are out. Whenever lowering
or raising tape into or out of the columns, R13 is picked.
13AL, BL (10.01)
N/C
N/O
Allow the vacuum column switches to control the reel
clutches, keeping tape in the center third of the columns.
Remove reel clutch control from the vacuum column switches,
allowing only the stop clutches to be energized.
R14, Photo light (09. 01) It is always picked when 48v power is on machine. When
dropped, it indicates a burned-out photo light.
14AL (09.04)
Drop the run relays if any photo light burns out while low -
speed rewinding, or if the load point or tape end light burns
out while reading or writing.
14BU (09.04) Prevent starting a load rewind operation if: (a) unloaded
and any photo cell is burned out, (b) loaded and the load
point or tape-end photo light is burned out.
R17, Power on reset
(09.01)
17-1 (09.04)
17-3 (09.02)
It is picked when all the DC supplies are up in the control
unit, and the 48v supply is up in the tape drive.
Drop the run relays in case of DC power failure.
It supplies a pow er-on reset to the tape indicator trigger in
case power is brought up on a loaded machine.
17-4 (09.06)
Phase 3 is picked separately to allow the vacuum motor to
run. (Phases 1 and 2 cannot pick until the vacuum motor is
up to speed.)
R19. Load point reset
(09.03)
It is picked while unloading and when unloaded. It is also
picked when starting from load point until the load point r e ­
lay drops. The load point relay was not latch tripped directly
because a standard latch trip relay with the correct imped­
ance is not available.
19-1 (09.03) Latch trip the load point relay when leaving load point.
R20, Start (09. 04) It is picked with the start key, providing the door is closed
and the machine is not unloaded. It holds until the door is
opened, or until the reset key is pressed.
88