D
D
B
B
8
8
1
1
0
0
A
A
D
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D
C
C
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S
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V
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1
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.
.
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Tel: (86)755-26434369
19
Web site: www.leadshine.com
DAMPED response like Figure 12. Remember tuning the servo is to get satisfying
performances, getting the best performances of the servo is a time consuming work.
So if the servo performance can meet your application requirements, then the easier
tuning way the better. Just like if the performances of the products can meet your
application requirements, then the cheaper the better.
(a) Max error (b) Steady state error
Figure 18: OVER DAMPED response
Usually manually induce an interference load to the motor shaft or the load, and
investigating or evaluating the response of the servo is also an easy way for an
experience engineer to tune the servo.
Tuning servo systems formed by DB810A drivers can be summarized as the
following rules:
1.
If servo system is UNSTABLE, then the first objective of tuning is to
stabilize the system. You can increase Damp or decrease Gain.
2.
If servo system is UNDER DAMPED, then increase Damp or decrease
Gain.
3.
If servo system is CRITICALLY DAMPED, then stop tuning.
4.
If servo system is OVER DAMPED, then decrease Damp or increase Gain.
D
D
B
B
8
8
1
1
0
0
A
A
D
D
i
i
g
g
i
i
t
t
a
a
l
l
D
D
C
C
S
S
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.
.
0
0
Tel: (86)755-26434369
20
Web site: www.leadshine.com
6. Using Tips
Current Limit Setting
The current Limit potentiometer is adjustable from 0 A to 20 A. Normally the Limit
potentiometer is set to Maximum Subtransient Current of the motor (default setting
is 20 A) unless you want to limit motor torque to a lower value.
When the torque demand due to load doesn
’
t exceeds current Limit setting, motor
speed and position are unaffected by the current Limit setting. When the current
Limit setting is active, the motor position may fall behind the command position
because of insufficient torque.
Alarm LED
Normally when the DB810A is first powered up, it will be necessary to push the
momentary switch to START servo for 2 seconds. This will clear the power-on reset
condition and extinguish the Alarm LED. The motor will then be enabled and the
drive will begin to operate.
After starting the servo, if a condition occurs that causes the DB810A to
“
fault out
”
,
such as the POSITION FOLLOWING ERROR reaches
±
128 counts, the ERR/RES
terminal will go to
“
0
”
, signaling the controller an error has occurred. The user must
correct the problem that caused the fault and then restart or re-enable the DB810A.
At anytime the user can pull the ERR/RES to
“
0
”
to immediately halt the DB810A
drive. See Figure 19. When the DB810A is in the
“
FAULT
”
state (Alarm LED lit),
all switching action stops, all internal counters are reset and the motor freewheels
and unpowered.
There are two conditions that will activate the protection function. One condition is
a short circuit occurs or current exceeds current Limit setting.
