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Appendix D
Error and Arithmetic Flag Operation
The following table shows the instructions that affect the ER, CY, GT, LT and EQ flags. In general, ER indi-
cates that operand data is not within requirements. CY indicates arithmetic or data shift results. GT indicates
that a compared value is larger than some standard, LT that it is smaller, and EQ, that it is the same. EQ also
indicates a result of zero for arithmetic operations. Refer to subsections of
Section 5 Instruction Set
for details.
Vertical arrows in the table indicate the flags that are turned ON and OFF according to the result of the in-
struction.
Although ladder diagram instructions,TIM, TIMW<13>, CNT, CNT<14>, TMHW<15>, and CNTR<12> are ex-
ecuted when ER is ON, other instructions with a vertical arrow under the ER column are not executed if ER is
ON. All of the other flags in the following table will also not operate when ER is ON.
Instructions not shown do not affect any of the flags in the table. Although only the non-differentiated form of
each instruction is shown, differentiated instructions affect flags in exactly the same way.
SR bits (25503 to 25507) change according to the result of the previously executed instruction. If the previous
instruction is a differentiated instruction, it will be executed only for the first scan in which the input conditions
are satisfied and so the SR bits will remain in the status determined by the result of the instruction executed
before the differentiated one.