FX
3G
/FX
3U
/FX
3UC
 PLC User's Manual - Positioning Control Edition
Built-in Positioning Functions
4 Before Programming
4.3 Various Special Relays for Operation Commands
B - 49
A
Common Items
B
Built-in 
Positioning 
Functions
Apx.
Example 
Connection
4.3.4 CLEAR Signal Output (DSZR/ZRN Instruction)
The DSZR instruction (zero return instruction with DOG search function) and ZRN instruction (zero return 
instruction) can stop the workpiece at the origin, and can output the CLEAR signal.
If it is necessary to output the CLEAR signal after zero return, turn on the "CLEAR signal output function 
enable" relay.  The following table shows the "CLEAR signal output function enable" relay of each pulse 
output destination device (Y000, Y001, Y002, Y003).
Use an FX
3U/FX3UC PLC Ver. 2.20 or later or FX3G PLC to specify the CLEAR signal output device.
→ For operation of DSZR instruction, refer to Section 6.2.
→ For operation of ZRN instruction, refer to Section 6.3.
1. If it is not necessary to use the CLEAR signal device specification function, or if an FX3UC PLC 
below Ver. 2.20 is used:
*1. Y002 (pulse output destination) cannot be specified when the 14-point or 24-point type FX3G PLC is 
connected.
*2. Devices related to Y003 (pulse output destination) are only valid if two FX
3U-2HSY-ADP adapters are 
connected to the FX
3U PLC.
*3. Use an FX
3U/FX3UC PLC Ver. 2.20 or later or FX3G PLC to use the "CLEAR signal device specification 
function enable" relay.
2. If it is necessary to use the CLEAR signal device specification 
function:
Turn on "CLEAR signal device specification function enable" relay to 
specify the CLEAR signal output device (output Y) for the pulse output destination device using the CLEAR 
signal device specification register.
*1. Y002 (pulse output destination) cannot be specified when the 14-point or 24-point type FX
3G PLC is 
connected.
*2. Devices related to Y003 (pulse output destination) are only valid if two FX
3U-2HSY-ADP adapters are 
connected to the FX
3U PLC.
→ For the CLEAR signal device specification method, refer to the next page.
If it is necessary to use a high-speed output special adapter:
The output devices initially set for the CLEAR signal of  the DSZR/ZRN instruction are the same output 
devices as the "direction signal / reverse pulse train (rotation direction signals)" of the high-speed output 
special adapters.  Be sure to specify output numbers of other transistor outputs using the CLEAR signal 
device specification function.
Pulse output 
destination 
device
Status of "CLEAR 
signal output 
function enable" 
relay
Status of "CLEAR signal 
device specification 
function enable" relay
*3
CLEAR signal device 
number
Y000 M8341=ON M8464=OFF Y004
Y001 M8351=ON M8465=OFF Y005
Y002
*1
M8361=ON M8466=OFF Y006
Y003
*2
M8371=ON M8467=OFF Y007
Pulse output 
destination 
device
Status of "CLEAR 
signal output function 
enable" relay
Status of "CLEAR signal 
device specification 
function enable" relay
CLEAR signal device number
CLEAR signal device 
specification register
Initial value (CLEAR 
signal device)
Y000 M8341=ON M8464=ON  D8464 -
Y001 M8351=ON M8465=ON  D8465 -
Y002
*1
M8361=ON M8466=ON  D8466 -
Y003
*2
M8371=ON M8467=ON  D8467 -