Panasonic FP7 Series Command Reference Manual page 238

3.46 ST=, ST<>, ST>, ST>=, ST<, ST<= (Data Comparison: Start)
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Outline of operation
Compares signed data specified in [S1] with signed data specified in [S2].
Begins a logic operation as a contact connected when the comparison result is in the specified
state (such as =, <, or >).
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Comparison result and operation
Relationship between [S1] and [S2]
Comparison instruction
(Note 1) ● "< >" represents "≠".
● ">=" represents "≥".
● "<=" represents "≤".
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Operation Example
Program operation of "ST >=" in the ladder diagram
Compares the value of data register DT0 with K70. If DT0 = K70, external output Y130 turns
ON.
DT0
70
40
10
Y130
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Precautions for use
● The "ST=", "ST<>", "ST>", "ST>=", "ST<", and "ST<=" instructions are initiated from the bus
bar.
● Since BCD data is assumed to be a negative value during comparison if the most significant
bit is 1, the comparison result may become incorrect. In such a case, use the BIN instruction
to convert the data into binary before comparison.
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Flag operations
Name
SR7
3-134
ST =
ST <>
ST >
ST >=
ST <
ST <=
Description
ON if the specified address using the index modification exceeds a limit.
[S1] < [S2] [S1] = [S2]
OFF ON
ON OFF
OFF OFF
OFF ON
ON OFF
ON ON
ON
OFF
[S1] > [S2]
OFF
ON
ON
ON
OFF
OFF
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