Data Initialization - GE PACSystems RX7i Cpu Programmer's Reference Manual

Chapter 4. Ladder Diagram (LD) Programming
4.8.7

Data Initialization

The Data Initialization (DATA_INIT) function copies a block of
constant data to a reference range.
When the DATA_INIT instruction is first programmed, the constants
are initialized to zeroes. To specify the constant data to copy, double-
click the DATA_INIT instruction in the LD editor.
Note: The mnemonics DATA_INIT_ASCII (refer to Data Initialize
ASCII) and DATA_INIT_COMM (refer to Data Initialize
Communications Request) operate differently from the other
six functions.
When DATA_INIT receives power flow, it copies the constant data to output Q. DATA_INIT's constant
data length (LEN) specifies how much constant data of the function type is copied to consecutive
reference addresses starting at output Q. DATA_INIT passes power to the right whenever it receives
power.
Notes:
The output parameter is not included in coil checking.
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If you replace one DATA_INIT instruction (except DATA_INIT_ASCII or DATA_INIT_COMM) with
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another (except DATA_INIT_ASCII or DATA_INIT_COMM), Logic Developer - PLC attempts to keep
the same data. For example, configuring a DATA_INIT_INT with eight rows and then replacing the
instruction with a DATA_INIT_DINT would keep the data for the eight rows. Some precision may
be lost when replacing a DATA_INIT_ instruction, and a warning message will be displayed when
this case is detected.
Operands
Note: For each mnemonic, use the corresponding data type for the Q operand. For example,
DATA_INIT_DINT requires Q to be a DINT variable.
Parameter Description
Length The quantity (default 1) of constant data copied
to consecutive reference addresses starting at
output Q.
Q The beginning address of the area to which the
data is copied.
Example
On the first scan (as restricted by the #FST_SCN system
variable), 100 words of initial data are copied to %R00005
through %R00104.
156 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual
Allowed Operands
Constants
All, except %S. SA, SB, and SC are not
allowed for REAL, LREAL, INT, and UINT
versions.
Mnemonics:
DATA_INIT_DWORD
DATA_INIT_DWORD
DATA_INIT_INT
DATA_INIT_UINT
DATA_INIT_REAL
DATA_INIT_LREAL
DATA_INIT_WORD
Optional
No
No
GFK-2950C