Mitsubishi Electric FX3S Series User Manual page 149

FX /FX /FX
3S 3G 3GC
Built-in Positioning Functions
1. Zero return operation
Zero return operation is described below assuming that Y000 is specified as the pulse output destination
device
relay (special auxiliary relay, special data register) below.
1) Specify the zero return direction.
Turn the "zero return direction specification" relay (M8342) on or off to specify the zero return direction.
2) Execute the DSZR instruction to perform zero return.
3) Transfer operation will be performed in the direction specified by the "zero return direction designation"
flag (M8342) at the speed specified by the "zero return speed designation" device (D8347, D8346).
4) If the near-point signal (DOG) specified by
speed (D8345).
5) After turning the near-point signal (DOG)
turned on
If the same input is specified for both the near-point signal and the zero-phase signal, turning the near-
point signal (DOG) OFF
instruction where the zero-phase signal is not used).
6) If the CLEAR signal output function (M8341) is enabled (set to ON), the CLEAR signal (Y004) will be
turned on within 1 ms after the zero-phase signal is turned ON, and will be kept ON for "20 ms + 1 scan
time (ms)".
7) The current value register (D8341, D8340) will be reset to "0" (will be cleared).
8) The "Instruction execution complete" flag (M8029) will turn on, and the zero return operation will be
completed.
Current value register = "0"
(D8341,D8340)
Zero-phase signal
S
CLEAR signal
(Y004)
"Instruction
execution
complete"
flag M8029
*1.
*2.
*3.
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/FX /FX PLC User's Manual - Positioning Control Edition
3U 3UC
D . If Y001, Y002, or Y003 is specified, it is necessary to change the output number of each related
1
For details on related relays, refer to Section 4.1 to Section 4.4, or Subsection 6.2.2.
*2
, the pulse outputting operation will immediately stop.
*1
will immediately stop the pulse outputting operation (just like the ZRN
*3
 For details on the "Instruction execution complete" flag, refer to Subsection 4.7.4.
Creep speed
•
2
20 ms + 1 scan time (ms)
ON
When the instruction is turned off, M8029 is turned off.
This step is described assuming that the "DOG signal logic reverse" relay (M8345) is off. If this flag is
on, it is necessary to change the expression "on" to "off", and "off" to "on".
This step is described assuming that the "Zero-point signal logic reverse" relay (M8346) is off. If this
flag is on, it is necessary to change the expression "on" to "off", and "off" to "on".
PLCs operate in the sequence "CLEAR signal output  Pulse output stop".
FX /FX /FX
3S 3G 3GC
Set the CLEAR signal detection to "While on, droop pulses are always cleared" for connected
amplifiers (drivers).
The stop position may deviate if it is set to "Droop pulses are cleared on the leading edge".
search engine
S is turned on
1
*1
S
OFF , if the zero-phase signal specified by
1
Deceleration
time
(D8349)
(D8345)
S
•
DOG
1
Rear end Front end
*3
1 ms or less
6 Mechanical Zero Return - DSZR/ZRN Instruction
6.2 DOG Search Zero Return (DSZR Instruction)
*1
, the speed will be reduced to the creep
Acceleration
time
(D8348)
Maximum speed
(D8344,D8343)
Zero return speed
(D8347,D8346)
Bias speed
(D8342)
A
B
Apx.
S
is
2
Zero return
direction
M8342=OFF
B - 105