554
FX3S/FX3G/FX3GC/FX3U/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
20 Positioning Control – FNC150 to FNC159
20.5 FNC156 – ZRN / Zero Return
20.5 FNC156 – ZRN / Zero Return
Outline
This instruction executes a zero return, and aligns the mechanical position with a present value register inside the
PLC.
When the dog search function is required, use DSZR (FNC150) instruction.
→ For explanation of the instruction, refer to the Positioning Control Edition manual.
→ For cautions on using special high-speed output adapters,
refer to the Positioning Control Edition manual.
1. Instruction format
2. Set data
*1. Setting range: 10 to 32767 Hz for 16-bit operation
Following range for 32-bit operation
3. Applicable devices
S1:"D.b" is available only in FX3U and FX3UC PLCs. However, index modifiers (V and Z) are not available.
S2 : Specify Y000, Y001 or Y002
*2
transistor output from the main unit, or specify Y000, Y001, Y002
*4
or Y003
*4
from a high-speed output special adapter
*3
.
*2. Y002 is not available in FX
3G PLC (14-point and 24-point type) and FX3S/FX3GC PLCs.
*3. High-speed output special adapters can be connected only to FX
3U PLC.
*4. 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 FX3U PLC, a special high-speed output adapter is required.
• Outputs of special high-speed output adapters work as differential line drivers.
S3 : This function is supported only in FX
3G/FX3GC/FX3U/FX3UC PLCs.
S4 : This function is supported only in FX
3U/FX3UC PLCs.
Operand type Description Data type
Initial zero return speed
*1
16- or 32-bit binary
Creep speed [10 to 32767 Hz]
Device number for near-point signal (dog)
Bit
Device number (Y) from which pulses are to be output
Pulse output destination Setting range
FX3U PLC Special high-speed output adapter 10 to 200,000 (Hz)
FX3S/FX3G/FX3GC/FX3U/FX3UC PLCs Main unit (transistor output) 10 to 100,000 (Hz)
Oper-
and
Type
Bit Devices Word Devices Others
System User Digit Specification System User
Special
Unit
Index
Con-
stant
Real
Number
Charac-
ter String
Pointer
XYMTCSD.b KnX KnY KnM KnS T C D R U\G V Z Modify K H E ""P
S3 S4
S3 S4
S1
S
2
FNC 156
ZRN
D
ZRN
16-bit Instruction
9 steps
Mnemonic Operation Condition
Continuous
Operation
DZRN
32-bit Instruction
17 steps
Mnemonic Operation Condition
Continuous
Operation
S
1
S
2
S
3
D
S
1
S
2
S
3
D