At Settings For Internal Variables - Omron CX-PROGRAMMER 5.0-FUNCTION BLOCK OPERATION Operation Manual

Function Block Applications Guidelines
Passing Values from or
Monitoring Output
Variables
External Variables:
Condition Flags, Clock
Pulses, Auxiliary Area
Bits, Global Symbols in
Program
Internal Variables:
Internally Allocated
Variables and Variables
Requiring AT Settings
2-4-3

AT Settings for Internal Variables

Program
Instance for function block definition A
The actual value is
passed
D00100 DATA_1
W500
DATA_2
The address can be specified, but the address itself is not passed.
• Values are passed in a batch from the input parameters to the input vari-
ables before algorithm execution (not at the same time as the instruction
in the algorithm is executed). Therefore, to pass the value from a parame-
ter to an input variable when the instruction in the function block algorithm
is executed, use an internal variable or external variable instead of an
input variable.
To paste into the program and then pass values outside (the program) from
the function block for each instance, or monitor values, use output variables.
Program
Instance for function block definition A.
The actual value is
passed.
Variable for passing a value outside or monitoring:
Use an output variable.
The following restrictions apply.
• Values are passed from output variables to output parameters all at once
after algorithm execution.
Condition Flags (e.g., Always ON Flag, Equals Flag), Clock Pulses (e.g., 1.0
second clock pulse bit), pre-registered Auxiliary Area Bits (e.g., First Cycle
Flag), and global symbols used in the program are all external variables
defined by the system.
Variables that are not specified as Inputs, Outputs, or Externals are Internals.
Internal variables include variables with internally allocated addresses, vari-
ables requiring addresses with AT settings (e.g., I/O allocation addresses,
addresses specially allocated for Special I/O Units), or variables requiring
array settings. For details on conditions requiring AT settings or array settings,
refer to 2-4-3 AT Settings for Internal Variables, and 2-4-4 Array Settings for
Internal Variables.
Always specify AT settings for internal variables under the following condi-
tions.
• When addresses allocated to Basic I/O Units, Special I/O Units, or CPU
Bus Units are used and these addresses are registered to global symbols
that cannot be specified as external variables (e.g., data set for global
symbols is unstable).
An input variable cannot be used to specify
the address of an operand that specifies
the the first (or last) address of multiple
words.
For example, the XFER (BLOCK
TRANSFER) instruction cannot be used to
If the size of the data type in
transfer 10 words from the address
DATA_1 is 1 word, the value
beginning with DATA_1 to the address
for the word D00100 is
beginning with DATA_2.
passed.
If the size of the data type in
DATA_2 is 2 words, the value
for the 2 words W500 and
W501 is passed.
OK_Flag W0.00
NG_ Flag W0.01
Section 2-4
XFER
&10
DATA_1
DATA_2
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