5-23
5-6 Full Closing Control
OMNUC G5-SERIES AC SERVOMOTOR AND SERVO DRIVE USER'S MANUAL
5
BASIC CONTROL Mode
5-6 Full Closing Control
An externally provided scale is used to directly detect the position of the control target and
feedback the detected machine position to perform position control. This way, controls become
possible that is not affected by ball screw error, temperature shift, etc. You can achieve highly
accurate positioning by configuring a full closing control system.
Outline of Operation
Precautions for Correct Use
If the electronic gear ratio is 1 : 1, 1 command pulse from the encoder constitutes 1 external scale
pulse. Since the electronic gear ratio is set differently than in the POSITION CONTROL mode, set
the external scale dividing ratio correctly.
To prevent machine damage due to an external scale setting error, set the following parameters
to appropriate values.
• Internal/External Feedback Pulse Error Counter Overflow Level (Pn328)
• Internal/External Feedback Pulse Error Counter Reset (Pn329)
For the setting of external scale ratio, it is recommended that 1/40
≤
External scale ratio
≤
160 be
satisfied.
If the external scale ratio is set excessively small, control to the unit of 1 external scale pulse may
be disabled.
If the external scale ratio is increased, on the other hand, operating noise may increase.
Driver
OMNUC G5
Motor
OMNUC G5
External scale
Controller
(pulse train output type)
Pulse train
+
CW
−
CW
+
CCW
−
CCW
3
4
5
6
+
CWLD
−
CWLD
+
CCWLD
−
CCWLD
44
45
46
47
Electronic gear
(Pn008 to Pn010)
Numerator
Denominator
FULL CLOSING CONTROL mode
External Scale Dividing Ratio
(Pn324 to Pn325)
Numerator
Denominator
Position Control Unit
CJ1W-NC113/133
CJ1W-NC213/233
CJ1W-NC214/414
CJ1W-NC234/434
CJ1W-NC413/433
CS1W-NC113/133
CS1W-NC213/233
CS1W-NC413/433
CPU Unit with built-in
pulse I/O
CJ1M-CPU21/22/23
CP1H-X/XA/Y
CP1L-M/L
Flexible Motion
Controller
FQM1-MMP22
Position
detection
+
EXB
−
EXB
+
EXZ
−
EXZ
+
EXS
CN5
CN1
−
EXS
+
EXA
−
EXA