316
Inverter Positioning
Section 7-3
7-3
Inverter Positioning
7-3-1
Features
Positioning can be achieved using an inverter. This enables a far more eco-
nomical positioning system than with a servomotor.
Feedback Control
with Error Counter
A position error counter built into the CP1L-EL/EM CPU Unit enables high-
precision positioning with an Inverter using feedback control. The PULSE
OUTPUT instruction is used in the ladder program in the CP1L-EL/EM CPU
Unit to output internal pulses to a built-in error counter.
The error counter calculates the position error from the number of input inter-
nal pulses and the number of feedback pulses from the rotary encoder, and
sends speed commands to the inverter so that the position error goes to zero.
Reducing Positioning
Time
With traditional inverter positioning, positioning patterns are created in which
set positions are detected to trigger changes in the speed. Pulses are read
from the encoder and compared to set values during positioning to enable
determining when a position requiring a speed change has been reached.
This results in positioning errors at speed-change points when stopping at
high speed, reducing stopping precision. To ensure high-precision positioning,
sufficient deceleration was required before stopping, but this increases the
positioning time.
With the CP1L-EL/EM’s inverter positioning function, feedback pulses are
used so that the prevent position is always known, increasing positioning
accuracy. And because preset positioning patterns are used for deceleration
and stopping, positioning time is reduced.
MAC Address:
01234567890A
00
NC
02
04
06
08
10
00
02
04
06
08
10
01
COM
03
05
07
09
11
01
03
05
07
09
11
BKUP
ERR/ALM
LNK/ACT
SYSMAC
CP1L
POWER
RUN
INH
1
00
01
02
03
04
06
00
01
03
04
06
COM
02
COM
05
07
COM
COM(V+)
05
07
ANALOG INPUT
V1+ V2+ COM
2
CP1L-EL/EM CPU Unit
Feedback pulses
Ladder program
Inverter
PLS2 instruction
Speed command
RS-485 or analog output
Encoder
Motor
Error
counter
Positioning
instruction
Frequency
command
Internal pulses
Summary of Contents for CP1L-EL20DR-D
Page 3: ...CP1L EL20D CP1L EM30D CP1L EM40D CP1L EL EM CPU Unit Operation Manual Produced July 2017...
Page 4: ...iv...
Page 10: ...x...
Page 22: ...xxii...
Page 34: ...xxxiv Software Licenses and Copyrights 7...
Page 192: ...158 Trial Operation and Debugging Section 5 3...
Page 250: ...216 Automatic Clock Adjustment and Specifying Servers by Host Name Section 6 7...
Page 666: ...632 Trouble Shooting Section 11 7...
Page 696: ...662 Standard Models Appendix A...
Page 805: ...771 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 806: ...772 Connections to Serial Communications Option Boards Appendix F...
Page 836: ...802 PLC Setup Appendix G...
Page 838: ...804 TCP Status Transitions Appendix H...
Page 840: ...806 Ethernet Network Parameters Appendix I...
Page 842: ...808 Buffer Configuration CP1L EL EM Appendix J...
Page 844: ...810 Ethernet Specifications Appendix K...
Page 851: ...Index 817 work words 118 write protection 447...
Page 852: ...818 Index...
Page 854: ...820 Revision History...
Page 855: ......