Figure 4.6.20 Position Level Detector - Fujitsu M2361A Customer Engineering Manual

k. Track crossing detector
The track crossing detect circuit generates the Track Crossing signal
(TKXNG) by means of PARl sent from the state detect circuit and OFTRK
sent from the position level detect circuit. The Track Crossing
Pulse (TKXGP) used to decrement the difference counter is generated
on the rising edge of TKXGP. At rezero operation, *GHRZ is activated
to prevent TDXGP from being generated.
1. Position level detector
4 - 80
The position level detect circuit generates the Off-Track signal
(OFTRK) by slicing the position signal (POSN, POSQ) and also
generates the On-Track signal (*ONTRK) by slicing Clamped Position
signal (CLPOS) output from the position error circuit.
OFTRK is used in the circuit which generates the track crossing pulse
for decrementing the difference counter in the logic circuit. *ONTRK
is used to generate switching signal (*ENDDC) which changes the
control method from the coarse control to the fine control, the
signal (ENDAC) which indicates the end of carriage acceleration, and
the signal (TFTMR) which indicates, after the control is switched to
the fine control, that the head is positioned properly.
POSN
ov
POSQ
ov
OFTRK
PARI
·PARI
TKXNG
TKXGP
Figure 4.6.20 Position Level detector
B03P-482S-0002A •.• Ol