Instruction manual
9.
TROUBLESHOOTING
(2)
How
to
find
the
cause
of
position
shift
Positioning unit
Servo
amplifier
(a) Output pulse
counter
Electronic gear (parameters
No.
3,4)
Machine
-
b-
CMX
CDV
P
(A)
;
(B)
(b)
Cumulative command
I
I
(C)
Servo
on (SON),
pulses
-
stroke end
(LSPLSN) input
C
n
-c
-
(c) Cumulative
feedback pulses
When a position
sM
occurs, check (a) output pulse counter,
(b)
cumulative command pulse display, (c)
cumulative feedback pulse &splay, and (d) machme stop position in the above hagram.
(A),
(E%)
and (C) inhcate position
sldt
causes.
For
example,
(A)
indicates that noise entered the wiring
between positioning
unit
and servo amphlier, causing pulses to be mis-counted.
In
a
normal status without position
sM,
there are the following relationships:
1)
Q
=
P
(positioning unit’s output counter
=
servo amphlier’s cumulative command pulses)
2)P
*
CMX (parameter
No.
3)
CDV (parameter
No.
4)
=
C (cumulative command pulses
x
electronic gear
=
cumulative feedback pulses)
3)
C
*
At
=
M (cumulative feedback pulses
x
travel per pulse
=
machine position)
Check for a position
shdt
in
the following sequence:
1)WhenQ
t
P
Noise entered the pulse train signal wiring between positioning unit and servo amphfier. causing
pulses to be miss-counted. (Cause
A)
Make the following check or take the following measures:
*
Check how the shleldmg
is
done.
Change the open collector system
to
the dlfferential line driver system.
.
Run wiring away from the power circuit.
Install
a
data he
lilter.
(Refer to Section
12.2.4.)
2)When
P
*-
CMX
+C
CDV
During operation, the servo on signal
(Soh3
or forwardheverse rotation stroke end
signal
was
switched
off
or
the clear signal (CR) and the reset signal
(RES)
switched on. (Cause
C)
If
a
malfunction may occur due to much noise, increase the input filter setting (parameter
No.
1).
3)When C
Af
t
M
Mechanical slip occurred between the servo motor and machine. (Cause
B)
9-
3