Slope Sequence During Rundown - HP 3456A Operating And Service Manual

SLOPE
$ . � SLOPE
f6
c( ' ,
!7
o
-!:
5-4
�
:
:
SLOPE
'
:
,
1 9
. ,
"
'"
.
"
COUNTS
TO: FRAC enabled, starts counting ALE's
TO;
T 1 : FRAC senses that slope is already positive; Slope direction must be reversed to reach zero-crossing; Ma)( of 2 AID courllS
alter FRAC lets 5 +0 through (flat periodl; Counting STOPS during 5 +0 period when logic decisions are being made.
5 +
T2: slope starls; FRAC starts AID counting again; 5 + 4 slope lasts for max of 1 2 AID counts or until lero crossing.
4
T3-T6: AID count periods; FRAC strobes microprocessor at each AID time.
T7: Zero crossing occurs; FRAC will detect this event but will continue to count until next AID count occurs.
TB: AID Count; FRAC lets 5 + 0 through; counting stops.
5
T9: - 3 Slope starts; Will last for max of 1 6 AID counts or until zero crossing occurs.
Zero-crossing occurs; FRAC detect zero-crossing but continues counting until next AID count; NOTE: FRAC continues the
T 0:
1
AID counting, stobing microprocessor, detecting zero,crossing. etc. For all
it did lor the 5
± 4
5- slope with negative input signal (input signal is positive for TO-TS example)
A:
4
Zero-crossing occurs; FRAC detects this crossing but continues to count.
B:
C: AID Count; 5 + 0 let through; AID counting stops; 5 +
always cross zero going in a positive direction; This 5 +
" ... � 17 AlC
$'2 SLOPE
MX I 6 oVO
COUNTS
T 1 M E
1 5
ALE's -
slopes.
Figure 8·42. Slope Sequence During Rundown.
1.
Slopes not dr8wn to scale for illustra­
tion purposes. 2.
Input signal volt8ge to integrator i s
switched off during rundown.
COUMTS
1 AID Countl; Rundown always SUHIS with S
01
the remaining slopes in the same manner as
slope will follow the 5+0 period so thal the final 5- 1 slope win
4
slope win last until lero·crossing occurs-max of
4
Figure 8-42. Slope Sequence During Rundown.
NOTES
'i-I
"All 18 .vD
5LOPf
flN1IL ZEM­
COUNTS
C"IQSS\NG
- slope.
4
AID counts.
2
8-38