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7 FBD/LD LANGUAGE
7.1 Configuration
■Inverting input and output points
Worksheet
A worksheet is a work area for inserting program units and for connecting them with wires.
Constant
Methods for expressing constants
The following table shows the expression methods for setting a constant in FBD/LD language.
For the expression methods other than the one described the above, refer to the following.
Page 40 Constant
Labels and devices
Specification method
You can directly describe and use labels and devices in an FBD/LD program. You can use labels and devices for inputs and
output points of units, for arguments of standard functions/function blocks, return values, and so forth.
For available labels, refer to the following.
Page 32 LABELS
For available devices, refer to the following.
MELSEC iQ-F FX5 User's Manual (Application)
■Device expression with type specification
A word device can be used as any data by adding a device type specifier to its name. If you do not specify a data type, the
word device operates as a word [signed] (INT).
For the device type specifiers and the devices you can use, refer to the following.
Page 60 Device expression with type specification
If you do not specify a data type for a word device, the data type is determined by the type of device.
You can invert an input to an unit or an output from an unit by using a connecting point.
The connecting point having been inverted is circled with a black circle. The data to be input or
output is inverted (FALSE to TRUE or TRUE to FALSE).
You can invert the following data types: BOOL, WORD, DWORD, ANY_BIT, and ANY_BOOL.
Data type Expressing method Example
String(32) STRING Enclose character strings with single quotation ( ' ).
Word device Data type
The current value of a timer device (TN), the current value of a retentive timer device (STN), the current value of a counter
device (CN)
WORD
The current value of a long counter device (LCN) DWORD
Other than the above INT
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