Mitsubishi Electric FX3U SERIES - Page 157

FX 3S /FX 3G /FX 3GC /FX 3U /FX 3UC PLC User's Manual - Positioning Control Edition
Built-in Positioning Functions
6 Mechanical Zero Return - DSZR/ZRN Instruction
6.3 Zero Return (ZRN Instruction)
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A
Common Items
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Built-in Positioning Functions
Apx.
Example Connection
3) For , specify the near-point signal (DOG) input device number (NO contact).
Turning on the near-point signal will reduce the speed to the creep speed. Turning off the near-point
signal will complete the zero return operation.
For details, refer to "1. Zero return operation".
• If an input X000 to X007 (X000 to X005 for FX
3S PLC) of the main unit is specified for the near-point
signal (DOG), the PLC interruption function will be used to stop the operation. (To output the CLEAR
signal, turn on the "CLEAR signal output function enable" relay.)
Under the following condition, however, operation may be affected by the input filter or the scan time of
the sequence program, and the operation, therefore, may not be stopped exactly at the origin.
- An input number of X010 or higher (or other device (auxiliary relay, etc.)) is specified.
If an input relay X010 or higher (X006 or higher for FX
3S PLC) is specified for the near-point signal
(DOG), the input filter will be applied.
4) For , specify a pulse output number in the range of Y000 to Y003.
5) Zero return direction
For this instruction, the zero return direction is set to the reverse rotation direction.
(During zero return operation, the value indicated in the current value register will be decreased.)
To perform zero return in the forward rotation direction, follow the example program below to control the
direction output.
For programming details, refer to Section 4.7.
To use the main unit (transistor output), refer to Section 4.8.
To use a high-speed output special adapter, refer to Section 4.9.
a) Turn on Y (rotational direction signal).
b) Refresh Y output using the REF (FNC 50) instruction.
c) Execute the ZRN instruction (zero return instruction).
d) With the execution completion flag (M8029) of the ZRN instruction (zero return instruction), reset
Y (rotational direction signal).
Example program:
In the program shown below, Y004 is specified as the rotation direction signal output device for Y000.
S
3
D
Command
input
Turns on (sets) Y004 as the
rotational direction signal of
Y000 (pulse output destination).
M12
K8Y000
Y000
Y004RST
Refreshes Y000 to Y007.
Executes ZRN instruction.
Resets the rotational direction
signal (Y004) using the instruction
execution complete flag.
Y004SET
FNC 50
REFP
FNC156
DZRN
S1• S2• S3•
M8029
M11RST
M12SET
M10RST
M10SET
M12RST
M12RST
Origin data reading completion
flag
Y004RST
M8329
M11SET
Abnormal end of zero return
a)
b)
c)
d)
Resets the rotational direction
signal (Y004) using the
instruction execution abnormal
end flag.
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