1. AXIS CONTROL
B–61393E–2/01
1.4
SETTINGS RELATED
TO SERVO–
CONTROLLED AXES
The servo interface of the Series 0 features the following:
Digitally controlled AC servo motor
Motor feedback with serial pulse coders
(1) Absolute pulse coder with a resolution of 1,000,000 pulses/rev
(2) Absolute pulse coder with a resolution of 65,536 pulses/rev
(3) Incremental pulse coder with a resolution of 10,000 pulses/rev
Scale feedback with A/B/Z signal interface
1.4.1
Parameters Related to
Servo
General
Explanation of terms frequently used in CNC
Least command increment
The minimum unit of a command to be given from CNC to the
machine tool
Detection unit
The minimum unit which can detect the machine tool position
Command multiplier (CMR)
A constant to enable the weight of CNC command pulses to meet the
weight of pulses from the detector
Detection multiplier (DMR)
A constant to enable the weight of CNC command pulses to meet the
weight of pulses from the detector
CAUTION
The relations among the least command increment,
detection unit, CMR, and DMR are as specified below.
Least command increment = CMR
detection unit
Detection unit =
DMR
Move amount per revolution of motor
number of pulses of detector per revolution
The flexible feed gear function in the digital servo defines
constant DMR using two parameters (Nos.8x84 and 8x85
(x : axis number)) n and m (DMR = n/m).
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1. AXIS CONTROL
B–61393E–2/01
Parameter
POWER OFF
0004
#7
POWER OFF
0005
#7
#6
#6
#5
DMRX
#4
#5
DMRZ
#4
#3
#2
#3
#2
DMRY
POWER OFF
0006
#7
#6
#5
DMR3
#4
#3
#7
#6
#0
#1
#0
#5
DMR4
#4
GRDZ
(T series)
GRDY
(M series)
#2
DMRZ
POWER OFF
0007
#1
GRDX
#3
#1
#0
GRD3
(T series)
GRDZ
(M series)
#2
#1
#0
GRD4
GRDx Specify the reference counter size for each axis as listed below:
Setting value
Reference counter size
#3
#2
#1
#0
Other than digital servo
0.1µ detector
Digital servo
0.1µ detector
0
0
0
0
1000
10000
0
0
0
1
2000
20000
0
0
1
0
3000
30000
0
0
1
1
4000
40000
0
1
0
0
5000
50000
0
1
0
1
6000
60000
0
1
1
0
7000
70000
0
1
1
1
8000
80000
1
0
0
0
9000
90000
1
0
0
1
10000
100000
1
0
1
0
11000
110000
1
0
1
1
12000
120000
1
1
0
0
13000
130000
1
1
0
1
14000
140000
1
1
1
0
15000
150000
1
1
1
1
16000
160000
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1. AXIS CONTROL
B–61393E–2/01
DMRx Specify the detection multiply value (DMR) for each axis as follows:
#7
#6
#5
#4
Detection multiplier
0
0
0
1/2
0
0
1
1
0
1
0
3/2
0
1
1
2
1
0
0
5/2
1
0
1
3
1
1
0
7/2
1
1
1
4
#6
#5
#4
#3
#2
0010
#1
OFFVY
#0
[Data type] Bit
OFFVY When velocity control ready signal VRDY is set ON before position
control ready signal PRDY comes ON
0 : A servo alarm is generated.
1 : A servo alarm is not generated.
#7
#6
0021
#5
APC8
#4
APC7
#3
APC4
#2
APC3
#1
APCZ
#0
APCX
(T series)
APC8
APC7
APC4
APCZ
APCY
APCX
(M series)
APCx Specify whether to use absolute pulse coder detector for each axis, as
follows:
0 : Do not use
1 : Use
#7
#6
0022
#5
ABS8
#4
ABS7
#3
ABS4
#2
ABS3
#1
ABSZ
#0
ABSX
(T series)
ABS8
ABS7
ABS4
ABSZ
ABSY
ABSX
(M series)
ABSx Specify whether the reference position for the absolute pulse coder of each
axis has been established, as follows:
0 : Not established
1 : Established
#7
0037
#6
#5
SPTP8
#4
SPTP7
#3
SPTP4
#2
SPTP3
#1
SPTPZ
#0
SPTPX
(T series)
SPTP8
SPTP7
SPTP4
SPTPZ
SPTPY
SPTPX
(M series)
SPTPx Specify whether to use a separate pulse coder for each axis, as follows:
0 : Do not use
1 : Use
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1. AXIS CONTROL
B–61393E–2/01
0100 – 0103
Command multiply (CMR)
NOTE
When this parameter has been set, the power must be
turned off before operation is continued.
[Data type] Byte
Set a command multiply indicating the ratio of the least command
increment to the detection unit for each axis.
Least command increment = detection unit x command multiply
Relationship between the increment system and the least command
increment
Least command increment
Increment system
IS–A
IS–B
IS–C
Unit
Metric input
0.01
0.001
0.0001
mm
Inch input
0.001
0.0001
0.00001
inch
Rotation axis
0.01
0.001
0.0001
deg
The value set in the parameter is obtained as follows:
(1) When command multiply is 1/2 to 1/27
1
Set value =
+ 100
(Command multiply)
Valid data range: 102 to 127
(2) When command multiply is 1 to 48
Set value = 2
command multiply
Valid data range: 2 to 96
NOTE
When command multiply is 1 to 48, the set value must be
determined so that an integer can be set for command
multiply.
0504 – 0507
Positioning deviation limit in movement
[Data type] Word
[Unit of data] Detection unit
[Valid data range] 0 to 32767
Set the positioning deviation limit in movement for each axis.
If the positioning deviation exceeds the positioning deviation limit during
movement, a servo alarm is generated, and operation is stopped
immediately (as in emergency stop).
Generally, set the positioning deviation for rapid traverse plus some
margin in this parameter.
32
1. AXIS CONTROL
B–61393E–2/01
0508 – 0511
Grid shift
[Data type] Word
[Unit of data] Detection unit
[Valid data range] 0 to "32767
A grid shift is set.
To shift the reference position, the grid can be shifted by the amount set in
this parameter. Up to the half of maximum value counted by the reference
counter can be specified as the grid shift.
NOTE
When this parameter has been set, the power must be
turned off before operation is continued.
0512 – 0515, 0517
Servo loop gain
(M series)
[Data type] Word
[Unit of data] 0.01 s –1
[Valid data range] 1 to 9999
Set the loop gain for position control.
When the machine performs linear and circular interpolation (cutting), the
same value must be set to parameter 0517. For machines that require only
positioning, parameter 0517 must be 0, but the settings of parameters
0512 to 0515 can vary from axis to axis. As the loop gain increases, the
response by position control is improved. A too large loop gain, however,
makes the servo system unstable.
The relationship between the positioning deviation (the number of pulses
counted by the error counter) and the feedrate is expressed as follows:
Positioning deviation = feedrate
(loop gain)
60
Unit: Positioning deviation mm, inches, or deg
Feedrate: mm/min, inches/min, or deg/min
Loop gain: s–1
0593 – 0596
Positioning deviation limit in the stopped state
[Data type] Word
[Unit of data] Detection unit
[Valid data range] 0 to 32767
Set the positioning deviation limit in the stopped state.
If, in the stopped state, the positioning deviation exceeds the positioning
deviation limit set for stopped state, a servo alarm is generated, and
operation is stopped immediately (as in emergency stop).
33