Mitsubishi Electronics FX3G User Manual

FX

3S

/FX

3G

/FX

3GC

/FX

3U

/FX

3UC

 Series

Programming Manual - Basic & Applied Instruction Edition

20 Positioning Control – FNC150 to FNC159

This instruction executes a zero return, and aligns the mechanical position with a present value register inside the
PLC.
In addition, this instruction enables the following functions not supported by the ZRN (FNC156) instruction:
• DOG search function
• Zero return by the near-point (dog) signal and zero-phase signal

It is not possible, however, to count the zero-phase signal and then determine the zero point.

→ For explanation of the instruction, refer to the Positioning Control Edition manual.

→ For cautions on using special high-speed output adapters,

S1 : "D .b" is available only in FX

3U

/FX

3UC

 PLCs. However, index modifiers (V and Z) are not available.

S2 : In the case of FX

3G

/FX

3GC

/FX

3U

/FX

3UC

 PLCs, specify X000 to X007.

In the case of FX

3S

 PLC, specify X000 to X005.

S3 : Specify Y000, Y001 or Y002

*1

 transistor output from the main unit, or specify Y000, Y001, Y002

*3

 or Y003

*3

from a high-speed output special adapter

*2

.

*1.

Y002 is not available in FX

3G

 PLC (14-point and 24-point type) and FX

3S

/FX

3GC

 PLCs.

*2.

High-speed output special adapters can be connected only to FX

3U

 PLC.

*3.

To use Y002 and Y003 with a high-speed output special adapter, connected a second high-speed output
special adapter.

Points                                                                                       
• When using a relay output type or triac output type FX

3U

 PLC, a special high-speed output adapter is required.

• Outputs of special high-speed output adapters work as differential line drivers.

Device number for near-point signal (dog)

Bit

Input number for zero-phase signal

Device number (Y) from which pulses are to be output

Device number to which rotation direction signal is output

System User

Digit Specification

System User

Special 

Unit

Index

Con-
stant

Real 

Number

Charac-

ter String

Pointer

X Y M T C S D .b KnX KnY KnM KnS T C D R U \G

V Z Modify K H

E

" "

P

S1

S

2

S

3

S

4

S1

FNC 150

DSZR

−

Mnemonic

Operation Condition

16-bit Instruction

 9 steps DSZR

Mnemonic

Operation Condition

Continuous

Operation

32-bit Instruction

  

S

1

  

S

2

  

D

1

  

D

2

  

S

1

  

S

2

  

D

1

  

D

2