Chapter 4. Ladder Diagram (LD) Programming
184
PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual
GFK-2950C
4.9.7
Search
When the Search function receives power, it searches the specified memory block
for a value that satisfies the search criteria. For example, SEARCH_GE_DWORD
searches for a DWORD that is greater than or equal to the specified value (the IN
operand).
Search can evaluate six different relationships for six data types, for a total of
thirty-six mnemonics.
Search Relationships:
SEARCH_EQ_
searches for a value of the specified data type
equal
to the IN operand.
SEARCH_GE_
searches for a value of the specified data type
greater than or equal
to IN.
SEARCH_GT_
searches for a value of the specified data type
greater than
IN.
SEARCH_LE_
searches for a value of the specified data type
less than or equal
to IN.
SEARCH_LT_
searches for a value of the specified data type
less than
IN.
SEARCH_NE_
searches for a value of the specified data type that is
not equal
to IN.
Data types:
BYTE, DINT, DWORD, INT, UINT, WORD
Searching begins at AR+INX, where AR is the starting address and INX is the index value into the
memory block. The search continues either until a register that satisfies the search criteria is found
or until the end of the memory block is reached.
▪
If a register is found, the Found Indication (FD) is set ON and the Output Index (ONX) is set to the
relative position of this register within the block.
▪
If no register is found before the end of the block is reached, the Found Indication (FD) is set OFF
and the Output Index (ONX) is set to zero.
The input index (INX) is zero-based, that is, 0 the means first reference, whereas the output index
(ONX) is one-based, that is, 1 means the first reference.
The valid values for INX are 0 to (Length - 1). The valid values for ONX are 1 to Length.
INX should be set to zero to begin searching at the memory block's first register. This value
increments by one at the time of execution. If the value of input INX is out-of-range,
(< 0 or > Length-1), INX is set to the default value of zero.
SEARCH passes power flow to the right when it performs without error. If INX is out of range,
SEARCH does not pass power flow to the right.
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