1. Near Origin Return to Origin ZRN

1.1. Instruction Description

When the input terminal is turned on, the return to origin ZRN command first sets the output pulse at the return speed. When the near point signal is set, it immediately decelerates from the return speed to the crawling speed set output pulse within a certain time. When the near point signal is reset, the pulse transmission stops. When the input terminal is turned off, pulse transmission immediately stops.

Pulse is outputting flag (read-only)：
register	Pulse port
M8134	Y000
M8135	Y001
M8136	Y002
M8137	Y003

For multi pulse series PLCs, the following registers are also available：
register	Pulse port
M8138	Y004
M8139	Y005
M8140	Y006
M8141	Y007
M8142	Y010
M8143	Y011

Pulse accumulation counting (read-write)：
register	Pulse port
D8140(D8141)	Y000
D8142(D8143)	Y001
D8144(D8145)	Y002
D8146(D8147)	Y003

For multi pulse series PLCs, the following registers are also available:
register	Pulse port
D8148(D8149)	Y004
D8150(D8151)	Y005
D8152(D8153)	Y006
D8154(D8155)	Y007
D8156(D8157)	Y010
D8158(D8159)	Y011

1.1.1. Attention：

After completing the return to origin action using this instruction, the pulse accumulation registers (D8140~D8158) of the corresponding output ports will automatically reset to zero, serving as the origin;
When the pulse command is used to output port Y, the Y port cannot be used for other purposes, that is, ordinary commands cannot perform ON or OFF operations on the Y port anymore;
For the ZRN directional return to origin command, if negative directional return to origin is required, both the regression speed and crawling speed must be set to negative values;

If the frequency of multiple pulse pulses exceeds 200K, a pull-up resistor needs to be added to the pulse output port to ensure that the pulse waveform is not distorted. The pull-up voltage is 24V, and the recommended pull-up resistor is 1K.

1.2. The valid operands of instruction

Input/Output	Data Type	operand	Description
HV	32-bit integer	D/CV/K/H/FD, bit composite word (X/Y/M/C/T/S), local variable (LD)	regression speed
LV	32-bit integer	D/CV/K/H/FD, bit composite word (X/Y/M/C/T/S), local variable (LD)	crawling speed
AC	16 bit unsigned integer	D/CV/TV/AI/AO/K/H/V/Z/FD, bit composite word (X/Y/M/C/T/S), local variable (LW)	acceleration time
DC	16 bit unsigned integer	D/CV/TV/AI/AO/K/H/V/Z/FD, bit composite word (X/Y/M/C/T/S), local variable (LW)	deceleration time
SIG	ON/OFF	X/M	Near Point Signal
OUT	ON/OFF	Y	Pulse
DIR	ON/OFF	Y	Direction

1.3. Example

Command table:

NETWORK 000

LDP M8151

MOVD K100000 D0//Regression speed, pulse frequency 100KHz

MOVD K5000 D2//Crawling speed, pulse frequency 5KHz

MOV K100 D4//Acceleration and deceleration time 100ms

NETWORK 001

LD M0

ZRN D0 D2 D4 X0 Y0 Y4//When M0 is' 1 ', a pulse with D0 frequency is output first at Y0. When a rising edge is received at X0, the output frequency of Y0 changes the speed from D0 to D2 within D4 time. If a falling edge is received at X0, the pulse transmission will be stopped directly

图1 ZRN11

图2 ZRN12