Mitsubishi FX1N Series Programming Manual

FX Series Programmable Controlers Applied Instructions 5
5-165
5.13.7 ZRN (FNC 156)
Contents:
When executing incremental or absolute
positioning, the PLC stores the current position
values which increase or decrease during
operation.
Using these values, the PLC always knows the
machine position. However when the power to the PLC is turned off, this data is lost. To cope
with this the machine should return to the zero point when the power is turned ON, or during
initial set up, to teach the zero position.
[S
1
] is the Zero Return Speed, [S
2
] is the Creep Speed, [S
3
] is the Near Point Signal, and [D] is
the Pulse Output Designation.
Points to note:
a)Users may specify zero return speed [S
1
] as, 16-bit 10 to 32,767Hz or 32-bit 10 to 100kHz.
b)Users may specify the creep speed [S
2
} of 10 to 32,767Hz
c)If any device other than an input relay (X) is specified for the Near point signal [S3] it will be
affected by the operation cycle of the PLC and the dispersion of the zero point may be large.
d)Only Y000 or Y001 can be used for the pulse output [D].
Because of the nature of the high speed output, transistor type output units should be used
with this instruction. Relay type outputs will suffer a greatly reduced life, and will cause false
outputs to occur.
To ensure a ‘clean’ output signal when using transistor type units, the load current should be
200mA or higher with the FX2N Series. The load current should be 10 - 100mA with the FX1S/
1N Series. It may be necessary to use ‘pull up’ resistors.
e)If M8140 is set to ON, the clear signal is sent to the servo motor when the return to zero point
is complete.
f)Related device numbers.
D8141 (upper digit) & D8140 (lower digit) : Current value register of Y000 (32-bit)
D8143 (upper digit) & D8142 (lower digit) : Current value register of Y001 (32-bit)
D8147 (upper digit) & D8146 (lower digit) : Maximum speed when FNC156, FNC158 or
FNC159 are executed 100~100,000Hz.
D8148 : Acceleration/Deceleration time adopted when FNC156, FNC158 or FNC159 are
executed.
Mnemonic Function
Operands
Program steps
S
1
S
2
S
3
D
ZRN
FNC 156
Zero return
Return to zero home
point after machine
ON or initial setting.
K,H,KnX,KnY,
KnM,KnS
T,C,D,V,Z
X,Y,
M,S
Y
Note: 
Y000 or
Y001 only
ZRN:
9steps
DZRN:
17 steps
FX 1S
FX 1N FX 2N
FX 2NC
PULSE-P 16 BIT OPERATION 32 BIT OPERATION
ZRN K1000 K100 Y000
[D][S
2][S1]
M0
X003
[S
3]

Mitsubishi FX1N Series Specifications

General

Programming Language	Ladder Logic
Output Type	Relay, Transistor
Operating Temperature	0 to 55°C
Power Supply	100-240V AC or 24V DC
Program Capacity	8K steps
Communication Ports	RS-422
Data Memory	8000 words
High-speed Counters	Up to 6 channels
Expansion Modules	Available
Pulse Output	2 points