FX Series Programmable Controlers Applied Instructions 5
5-5
5.1.1 CJ (FNC 00)
Mnemonic Function
Operands
Program steps
D
CJ
FNC 00
(Conditional
Jump)
Jumps to the
identified pointer
position
Valid pointers from the ran
e 0 to 63
CJ,
CJP:3steps
Jump pointer
P
PP
: 1 step
P9 CJ
P9
X20
[ D ]
X21
P 9
P 9CJ
P9
X20
CJ
X1
P 0CJ
P0
X0
M8000
Y1
Y0
END
Operation:
When the CJ instruction is active it forces the pro
ram
to
ump to an identified pro
ram marker. While the
ump takes place the intervenin
pro-
ram steps are
skipped. This means the
are not processed in an
wa
. The resultin
effect is to speed up the pro
rams
operational scan time.
Points to note:
a) Man
CJ statements can reference a sin
le pointer.
b) Each pointer must have a unique number. Usin
pointer P63 is equivalent to
umpin
to the END
instruction.
c) An
pro
ram area which is skipped, will not update
output statuses even if the input devices chan
e.
For example, the pro
ram opposite shows a
situation which loads X1 to drive Y1. Assumin
X1
is ON and the CJ instruction is activated the load
X1, out Y1 is skipped. Now even if X1 is turned
OFF Y1 will remain ON while the CJ instruction
forces the pro
ram to skip to the pointer P0. The
reverse situation will also appl
, i.e. if X1 is OFF to
be
in with and the CJ instruction is driven, Y1 will
not be turned ON if X1 is turned ON. Once the CJ
instruction is deactivated X1 will drive Y1 in the
normal manner. This situation applies to all t
pes of
outputs, e.
. SET, RST, OUT, Y, M and S devices
d) The CJ instruction can
ump to an
point within the main pro
ram bod
or after an FEND
instruction
