Mitsubishi Electric Melsec-F FX3GC Series User Manual page 103

FX /FX /FX /FX /FX
3S 3G 3GC 3U 3UC
Built-in Positioning Functions
2. Zero return instruction (ZRN instruction)
Zero return will be performed in the reverse rotation direction only.
(During zero return, the value indicated by the current value register will be decreased.)
To perform zero return in the forward rotation direction using the ZRN instruction (zero return instruction):
To perform zero return in the forward rotation direction, create a program to control the output (Y) relay set as
a "rotational direction signal" as follows:
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) Using the execution completion flag (M8029) of the ZRN instruction (zero return instruction), reset Y
(rotational direction signal).
Example program:
The following program uses Y004 as the rotational direction signal for Y000.
Command
input
M12
PLC User's Manual - Positioning Control Edition
To use
To use a high-speed output special adapter, refer to Section 4.9.
FNC 50
REFP
FNC156
S
1
DZRN
M8029
M8329
4.3 Various Special Relays for Operation Commands
For details on programming, refer to Section 4.7.
main unit (transistor output), refer to Section 4.8.
the
RST M10
RST M11
SET M12
a)
SET Y004
b)
Y000 K8
c)
S S Y000
2 3
d)
RST Y004
SET M10
Origin data reading completion flag
RST M12
Resets the rotational direction signal
RST Y004
(Y004) using the instruction
execution abnormal end flag.
SET M11
Abnormal end of zero return
RST M12
4 Before Programming
Turns on (sets) Y004 as the
rotational direction signal of Y000
(pulse output destination).
Refreshes Y000 to Y007.
Executes ZRN instruction.
Resets the rotational direction
signal (Y004) using the instruction
execution complete flag.
B - 59
A
B
Apx.