Sony BVH-2000, Operation And Maintenance Manual

Page: 325 / 505

(5-7-1. Outline of Servo System)
The HOST CPU is responsible for processing the control data,
providing interface with the system control system and carrying
out self-diagnosis. The HARD CPU is responsible
for handling
the data between the various boards which are used for the
servo systems.
The HOST CPU and HARD CPU function independently
and
even if either should CPU fail, the motors can be stopped
without the tape sustaining any damage.
The servo system processing must be conducted in synchronization
with the video signal, and a series of processing operations
are
conducted with interrupts being applied in V/2 units for the
HOST CPU and in V/8 units for the HARD CPU.
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The main data processed by the CPUs are as follows:
DRUM SERVO SYSTEM
PG Drum rotational phase data
FG Drum rotational speed data
PB V Tape recording data, Head/PG
relative phase data
CAPSTAN SERVO SYSTEM
FG Capstan rotational speed data,
Capstan rotation direction data
CTL . . . . . . . . . . . . . . . . . .. Tracking data
REEL SERVO SYSTEM
TENSION SENSOR .... Supply/Take-up tape tension
data
REEL FG Supply/Take-up reel rotational
speed data, rotation direction
data
TIMER FG . . . . . . . . . . .. Tape speed data, tape direction
data
PB H . . . . . . . . . . . . . . . . .. Skew error data
In response to the commands from the system control system,
the optimum data are output to the motors, solenoids and other
drive systems.
SERVO SYSTEM
5-7-2
BVH-2000(U/C)/PS/PM
BVH-2180(U/C)/PS/PM