Specifications

33
3. Replacement of FX2NC series
1
Introduction
2
Replacement of FX2N series
3
Replacement of FX2NC
series
4
Program changeover method
A
Models affected by production termination
B
Related manuals
C
Frequently asked questions
Item
Operational difference
Caution
FX
2NC series FX3UC series
Step ladder program
Range of device numbers
to be stored in D8040 to
D8047 when M8047 is
enabled.
Stores active state
numbers sequentially in
ascending order from
the range S0 to S899.
Stores active state
numbers sequentially in
ascending order from
the range S0 to S899,
S1000 to S4095.
Since the object device range
differs, add a program for
initializing S1000 to S4095.
Common
items
Instruction execution time
See 7. Execution
Times and Instructional
Hierarchy of the “FX1S/
FX1N/FX2N series
programming manual.”
See Appendix B:
Instruction Execution
Times of the “FX3G/
FX3U/FX3UC series
programming manual.”
Since the instruction execution
time varies, conrm operation for
programs that operate in concert
with the scan time.
Program ow
FNC00/01
If the destination of
a jump or call is not
available, an operation
error occurs when the
CJ or CALL instructions
are executed.
If the destination of a jump
or call is not available,
when not in RUN state,
a syntax error occurs.
However, if the pointer is
indexed, an operation error
occurs when executing the
instruction.
In the FX3UC, error detection before
RUN is implemented.
Check the program, and correct to
avoid errors.
Detection of error
designated by pointer not
using the CJ or, CALL
instructions.
Move, compare
FNC15
10 to 20ms per 8
consecutive points.
66 to 132ms per 500
consecutive points.*
* Even writing of one
point may require the
specied time.
When writing into le registers using
the BMOV instruction when a memory
cassette is in use, the scan time may be
extended when executing the BMOV
instruction.
During execution of the BMOV
instruction, the watch dog timer is not
refreshed. Insert the WDT command
as required or take other measures.
File register write execution
time using the BMOV
instruction
Shift
FNC34 to 37
If S or D device ranges
are overlapped, correct
operation results may
not be obtained, but
operation is executed.
If S or D device ranges
are overlapped, and
operation error (6710)
occurs, and operation is
not executed.
Since the operation result becomes
abnormal, the FX
3UC has been
changed so that an operation error
occurs. Make modications so as to
avoid an operation error.
Operation when devices are
overlapped with the SFTR,
SFTL, WSFR, WSFL
instructions.
Data processing
FNC40 If the ZRST instruction
designating a timer or
counter as the operand
is executed, the reset
coil of this timer or
counter is not cleared.
If the ZRST instruction
designating a timer or
counter as the operand
is executed, the reset
coil of this timer or
counter is also cleared.
In the FX2NC, to clear the reset
coil of a timer or counter, a RST
instruction was needed, but in the
FX3UC, batch resetting is possible
using the ZRST instruction.
Clearing of a reset coil with
the ZRST instruction.
FNC40
The ZRST instruction
resets the state of the
designated device,
but does not reset the
previous status for the
PLS or PLF instructions.
If a ZRST instruction
designating the same
device as a PLS
command has been
programmed previously,
the PLS instruction is
not performed again
unless the drive contact is
changed from OFF to ON.
The ZRST instruction
resets not only the state
of the designated device,
but also resets the
previous status for the
PLS or PLF instructions.
If a ZRST instruction
designating the same
device as a PLS
command has been
programmed previously,
the PLS instruction is
performed again if the
drive contact remains in
the ON status.
Change the drive contact of PLS
instructions to LDP instructions, or
add MEP instructions between drive
contacts and PLS instructions.
Combined operation of
the ZRST and PLS, PLF
instructions.
FNC48
M8020 (zero ag),
M8021 (borrow ag)
are not cleared when the
instruction is executed.
M8020 (zero ag),
M8021 (borrow ag)
is cleared when the
instruction is executed.
If a part of the program references
M8020 or M8021 after a SQR or
DSQR instructions, create a sequence
program to store the status of M8020
and M8021 in a separate device
before execution of the instructions.
Clearing timing of SQR,
DSQR instruction ags.