Mitsubishi Electric Melsec-F FX3GC Series User Manual page 159

FX /FX /FX /FX /FX
3S 3G 3GC 3U 3UC
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 D . If Y001, Y002, and Y003 are specified, it is necessary to change the output number of each
related relay (special auxiliary relay, special data register) below.
1) Execute the ZRN instruction to carry out zero return.
2) Transfer operation will be performed at the zero return speed specified by
3) If the near-point signal (DOG) specified by
speed specified by
4) If the near-point signal (DOG) specified by
immediately stopped.
5) If the CLEAR signal output function (M8341) is enabled (set to ON), the CLEAR signal (Y004) will be
turned on within 1 ms
"20 ms + 1 scan time (ms)".
6) The current value register (D8341, D8340) will be reset to "0" (will be cleared).
7) "Instruction execution complete" flag will be turned on, and the zero return operation will be completed.
CLEAR signal
Y004
"Instruction
execution
complete" flag
M8029
*1. Within 1 ms when an input X000 to X007 (X000 to X005 in the FX
signal (DOG), and within "1 ms + 1 scan time" when an input X010 or later (X006 or later in the FX
PLC) is used for the near-point signal (DOG).
*2. FX /FX
3S 3G
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".
PLC User's Manual - Positioning Control Edition
 For details on related flags, refer to Section 4.1 to Section 4.4, or Subsection 6.2.2.
S .
2
*1 after the near-point signal (DOG) is turns from ON to OFF, and will be kept ON for
*2
For details on "Instruction execution complete" flag, refer to Subsection 4.7.4.
Creep speed
S
2
DOG
Rear end
*1*2
20 ms + 1scan time (ms)
ON
When the instruction is turned off, M8029 is turned off.
PLCs operate in the sequence "CLEAR signal output  Pulse output stop".
/FX
3GC
6 Mechanical Zero Return - DSZR/ZRN Instruction
S is turned on, the speed will be reduced to the creep
3
S is turned off, the pulse outputting operation will be
3
Deceleration
time
(D8349)
Maximum speed
(D8344,D8343)
Zero return speed
S
1
S
3
Front end
6.3 Zero Return (ZRN Instruction)
S .
1
Acceleration
time
(D8348)
Bias speed
(D8342)
PLC) is used for the near-point
3S
B - 115
A
B
Apx.
3S