Mitsubishi Electric MELSEC-Q/L - Page 701

7 APPLICATION INSTRUCTIONS
7.15 Clock Instructions
699
7
• The following table shows the comparison operation results for each instruction.
Operation error
• There is no operation error in the LDDT, ANDDT, or ORDT instruction.
Instruction symbol Condition Comparison
operation result
Instruction symbol Condition Comparison
operation result
DT= (S1)=(S2) Conductive status DT= (S1)(S2) No-conductive status
DT<> (S1)(S2) DT<> (S1)=(S2)
DT> (S1)>(S2) DT> (S1)(S2)
DT<= (S1)(S2) DT<= (S1)>(S2)
DT< (S1)<(S2) DT< (S1)(S2)
DT>= (S1)(S2) DT>= (S1)<(S2)
• The following figure shows the comparison example of dates.
The following table shows the conductive states resulting from performing the comparison operation of the dates A, B, and C shown above.
Even if the objects to be compared are under the same condition, the comparison operation results vary depending on the objects selected.
Comparison objects Comparison condition (: Conductive, : No-conductive)
A<B B<C A<C
Day 
Month 
Month, day 
Year 
Year, day 
Year, month 
Year, month, day 
No objects 
• Even if the dates to be compared do not exist practically, this instruction executes the comparison operation for the objects with the settable dates in
accordance with the following condition.
Date A: 2006/02/30 (This date is settable, though it does not exist.)
Date B: 2007/03/29
Date C: 2008/02/31 (This date is settable, though it does not exist.)
Comparison objects Comparison condition (: Conductive, : No-conductive)
A<B B<C A<C
Day 
Month 
Month, day 
Year 
Year, day 
Year, month 
Year, month, day 
No objects 
A
(2006/9/22)
B
(2007/6/23)
C
(2008/8/8)
2009/1/12008/1/12007/1/12006/1/1