Basic Instructions
2 − 143
Explanation of example
Compares the contents of data register DT0 with the constant K60 when X0 turns on. If DT0 K60 in the X0
on state, external output relay Y30 goes on. If DT0 < K60 or if X0 is in the off state, external output relay Y30
goes off.
60
10
X0
Y30
DT0
on
off
on
off
Description
Compares the word data specified by S1 with the word data specified by S2 according to the comparison
condition.
The AN instruction results in serial connection as the liaison contact when the comparison result is a
specified status (=, <, >, etc.).
The result of the comparison operation is as follows:
Comparison
Condition
instruction
S1 < S2 S1 = S2 S1 > S2
AN= off on off
AN<> on off on
AN> off off on
AN>= off on on
AN< on off off
AN<= on on off
Precautions concerning usage
Multiple AND comparison instructions AN =, AN <>, AN >, AN >=, AN <, and AN <= can be used
consecutively.
If mixed with BCD or other type of data, the value will be regarded as negative when the most significant bit is 1
and a correct comparison may not be obtained. In this case, use an F81 (BIN) instruction or similar instruction
to change the data to binary data before making the comparison.
Flag conditions
・Error flag (R9007): Turns on and stays on when the area specified using the index modifier
exceeds the limit.
・Error flag (R9008): Turns on for an instant when the area specified using the index modifier
exceeds the limit.
< > indicates
>= indicates
<= indicates
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