Mitsubishi Melsec-A Series User Manual page 34

3.
SPECJFtCATlONS
/MELSEC
Zeroing data is explained below:
( 1 Zeroing direction
Specifies the direction for zeroing.
IMPORTANT
1
Zetoing is controlled according to the zeroing direction and
speed. Deceleration is started when an actuator is operated.
Always ensure that the zeroing direction is correct for
t h e
drive system used.
(2)
Zeroing methods
Zero the system using one
of the following methods, all methods
require a "zeroing dog" or actuator to reduce the speed to the creep
speed.
a ) Zero-phase signal from pulse generator (PG)
b) Stop and dwell timer time-out
c) Stop and signal from drive unit
(a) Zero-phase signal from PG
The sequence of events is as follows
( S e e
Fig. 3.1 1):
0
Zeroing signal received
-
move in appropriate direction,
0
"Zeroing dog" on
-
start decceleration to creep speed.
0
"Zeroing dog" off
-
continue at creep speed.
0
Zero phase signal
-
stop drive, zeroing complete.
I
J
Actuator signal starts deceleration.
Creep apead
I I I \
"Zeroing dog"
Drift (axording to drive unit)
I
Zero-phase signal
U
u
Adjust tha actuator
so
that its
OFF
U
zerophme signal.
position is near
the
center of the
'//////////////
Torque limit valid range
Fig. 3.11 Zeroing Using a Zero-Phase Encoder and an Actuator (method a1