1. Basic Understanding of Instructions
18
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Precautions for Correct UsePrecautions for Correct Use
The following instructions are executed even when the input conditions are OFF. Therefore,
when indirect memory addresses are specified using auto-incrementing or auto-decrementing
(,IR+ or ,IR-) in an operand of any of these instructions, the value in the Index Register (IR) is
refreshed each cycle regardless of the input condition (increases or decreases one every
cycle). This must be considered when writing a program.
The following ladder programming examples show how the index registers are treated.
Example 1
Ladder Program:
LD P_Off
OUT, IR0+
Operation: When the PLC memory address 0.13 is stored in IR0.
The input condition is OFF (P_Off is the Always OFF Flag), so the OUT instruction sets 0.13,
which is indirectly addressed by IR0, to OFF. The OUT instruction is executed, so IR0 is incre-
mented. As a result, the PLC memory address 0.14, which was incremented by +1 in the IR0,
is stored. Therefore, in the following cycle the OUT instruction turns OFF 0.14.
Example 2
Ladder Program:
LD P_Off
SET, IR0+
Operation: When the PLC memory address 0.13 is stored in IR0.
The input condition is OFF (P_Off is the Always OFF Flag), so the SET instruction is not exe-
cuted. Therefore, IR0 is not incremented and the value stored in IR0 remains PLC memory
address 0.13.
Classification Instructions
Sequence input instructions LD, LD NOT, AND, AND NOT, OR, OR NOT, LD TST(350), LD
TSTN(351), AND TST(350), AND TSTN(351), OR TST(350), OR
TSTN(351)
Sequence output instructions OUT, OUT NOT, DIFU(013), DIFD(014)
Sequence control instructions JMP(004), FOR(512)
Timer and counter instructions TIM/TIMX(550), TIMH(015)/TIMHX(551), TMHH(540)/TMHHX(552),
TIMU(541)/TIMUX(556), TMUH(544)/TMUHX(557), TTIM(087)/
TTIMX(555), TIML(542)/TIMLX(553), MTIM(533)/MTIMX(554), CNT/
CNTX(546), CNTR(012)/CNTRX(548)
Comparison instructions Symbol comparison instructions (LD, AND, OR =, etc.(function codes:
300, 305, 310, 320, and 325))
Single-precision floating-point
math instructions
Single-precision floating-point data comparison (LD, AND, OR = F,
etc.(function codes: 329 to 334))
Double-precision floating-point
math instructions
Double-precision floating-point data comparison (LD, AND, OR = D,
etc.(function codes: 335 to 340))
Block programming instruc-
tions
BPPS(811), BPRS(812), EXIT(806), EXIT(806) NOT, IF(802), IF(802)
NOT, WAIT(805), WAIT(805) NOT, TIMW(813)/TIMWX(816),
CNTW(814)/CNTWX(818), TMHW(815)/TMHWX(817), LEND(810),
LEND(810) NOT
Text string processing instruc-
tions
STRING COMPARISON (LD, AND, OR = $, etc. (function codes: 670 to
675))
To Next Page
Loading...
Need help?
General
