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Precautions Section 2-2
Specifying Operands for Multiple Words
With the CS/CJ-series PLCs, an instruction will be executed as written even if
an operand requiring multiple words is specified so that all of the words for the
operand are not in the same area. In this case, words will be taken in order of
the PLC memory addresses. The Error Flag will not turn ON.
As an example, consider the results of executing a block transfer with
XFER(070) if 20 words are specified for transfer beginning with W500. Here,
the Work Area, which ends at W511, will be exceeded, but the instruction will
be executed without turning ON the Error Flag. In the PLC memory
addresses, the present values for timers are held in memory after the Work
Area, and thus for the following instruction, W500 to W511 will be transferred
to D00000 to D00011 and the present values for T0000 to T0007 will be trans-
ferred to D00012 to D00019.
Note Refer to the appendix Memory Map of PLC Memory Addresses for specific
PLC memory addresses.
2-2-2 Special Program Sections
CS/CJ-series programs have special program sections that will control
instruction conditions. The following special program sections are available.
T0000
W500
W511
to
to
to
to
to
to
to
to
First destination word
First source word
Number of words
Trans-
ferred.
&10
Program section Instructions Instruction condition Status
Subroutine SBS, SBN, and RET instruc-
tions
GSBS, GSBN, and GRET
instructions
Subroutine program is exe-
cuted.
The subroutine program sec-
tion between SBN and RET
instructions is executed.
IL - ILC section IL and ILC instructions Section is interlocked The output bits are turned
OFF and timers are reset.
Other instructions will not be
executed and previous status
will be maintained.
Step Ladder section STEP S instructions and
STEP instructions
FOR-NEXT loop FOR instructions and NEXT
instructions
Break in progress. Looping
JMP0 - JME0 section JMP0 instructions and JME0
instructions
Jump
Block program section BPRG instructions and
BEND instructions
Block program is executing. The block program listed in
mnemonics between the
BPRG and BEND instruc-
tions is executed.
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