Stop Data Flow; Reader Stop Lights; Clutch Failures - IBM 1402 Reference Manual

-.
Stop Data Flow
Refer to Figure 6-2.
CL I CLOSED
158
0 -
188
0
CL TEST
CL 2 CLOSED
RD CL CYCLE (R-6)
NOT RD CL IMPULSE
(NOT R-IO)
RD CL IMPULSE
(R-IO)
NOT RD CL CYCLE
(NOT R-6)
Figure 6-2. Reader-Stop Data Flow
Reader Stop Lights
CAUSES
HOPPER CL
NOT CL 1 (R-2)
READ FEED
CL I DELAY (R-ll)
NOT CL2
R-13
JAM DETECT
1. Frequent misfeeding of cards: This is usually
caused by insufficient weight over the picker
knives, and indicates that the file feed needs ad-
justing.
The time delay should be at least three seconds
before the clutch operates. At least a
1~"
stack of
cards should be in the hopper.
2. Bouncing of card levers 1 and 2: Set cam display
switch first to
POSriION
5 and then to
POSITION
6.
Observe timer index while switch is being set. A
bouncing card lever will appear as a spot of light
between 158
0
and 188
0
•
Adjust card lever contacts.
3. Dropout of relays 2 or 10: This dropout could
cause false reader stops.
4. Failure of clutch to latch or unlatch: If reader
stops occur intermittently due to clutch failure,
these stops may be difficult to diagnose. Refer to
Clutch Failures.
Clutch Failures
The following methods should be followed to de-
termine whether or not the clutch has failed to latch
or unlatch.
METHOD A
This method pertains to 1402's used with an mM 1401.
6-2
NON-PROCESS RUN-OUT
1. Sync the scope
+
External on pin "E" of the 140i
read feed trigger (1401 system logics page 36. 10.
11.2). A Test hub is available on the CE Panel of
some 1401's.
2. Display the read feed pick RL CB which will
make at 120
0
and break at 170
0
•
Set time base to
5 ms/Div and adjust uncalibrated knob as needed
to get display shown. Set vertical deflection to
10 v/div.
3. Tum up scope intensity so the beam is visible on
the scope face without a sync. (This cannot be
done with the 561 scope.)
4. Any job that will cause failures may be run. Cor-
rect operation will display the read feed pick
RLCB with a scope sync. See condition A in
Figure 6-3.
5. If the scope traces without displaying the RLCB
pulse, the clutch has failed to trip. This will be
followed by a pulse at the left edge of the scope,
without a sync if the clutch does engage at the
next clutch latch time, following the initial fail-
ure, see cop.dition B in Figure 6-3.
6. If the scope does not trace, but a RLCB pulse is
seen at the left edge of the scope, this indicates
a failure of the card feed clutch to latch, or in-
dicates an extraneous clutch cycle. See condition
C in Figure 6-3.