Specifications

App-6
Appendix 2 Character Strings that cannot be Used in Label Names and Data Names
Appendix 2 Character Strings that cannot be Used in
Label Names and Data Names
Character strings used for application function names, common instruction names, special
instruction names, and instruction words are called reserved words.
These reserved words cannot be used for label names or data names. If the character string
defined as a reserved word is used for a label name or data name, an error occurs during
registration or compilation.
The following tables shows character strings that cannot be used for label names or data names.
The numbers from to in the tables indicate the following label names and data names.
Table App. 2-1 Character strings that cannot be used for label names and data names (1/3)
<Label name and data name>
Project file name
Program file name (Simple (without labels))
Program file name (Simple (with labels))
Program file name (structure)
Tas k n a me
Global label data name
Structure name
POU name
Label name
Category Character string
Class identifier
VAR, VAR_RETAIN, VAR_ACCESS, VAR_CONSTANT,
VAR_CONSTANT_RETAIN, VAR_INPUT, VAR_INPUT_RETAIN,
VAR_OUTPUT, VAR_OUTPUT_RETAIN, VAR_IN_OUT,
VAR_IN_EXT, VAR_EXTERNAL, VAR_EXTERNAL_CONSTANT,
VAR_EXTERNAL_CONSTANT_RETAIN,
VAR_EXTERNAL_RETAIN, VAR_GLOBAL,
VAR_GLOBAL_CONSTANT,
VAR_GLOBAL_CONSTANT_RETAIN, VAR_GLOBAL_RETAIN
Data type
BOOL, BYTE, INT, SINT, DINT, LINT, UINT, USINT, UDINT, ULINT,
WORD, DWORD, LWORD, ARRAY, REAL,
LREAL, TIME, STRING, TIMER, COUNTER, RETENTIVETIMER,
POINTER, Bit, Word [Unsigned]/Bit String [16-bit], Double Word
[Unsigned]/Bit String [32-bit], Word [Signed], Double Word
[Signed], FLOAT (Single Precision), FLOAT (Double Precision),
String, Time, Timer, Counter, Retentive Timer, Pointer
Data type hierarchy
ANY, ANY_NUM, ANY_BIT, ANY_REAL, ANY_INT, ANY_DATE
ANY_SIMPLE, ANY16, ANY32

*1
Device name
X, Y, D, M, T, B, C, F, L, P, V, Z, W, I, N, U, J, K, H, E, A, SD, SM,
SW, SB, FX, FY, DX, DY, FD, TR, BL, SG, VD, ZR, ZZ
*2

*1
Character string
recognized as device
(Device name +
Numeral)
Such as X0

*3
ST operator
NOT, MOD
(, ), -

*1
: Applicable, : With restrictions, : Not applicable
*1: Functions cannot be used.
*2: Whether to handle a device name indexed with ZZ device as a reserved word depends on the parameter
setting.
When Z device is specified for 32-bit index setting: Not handled as a reserved word
When ZZ device is specified for 32-bit index setting: Handled as a reserved word
*3: Applicable for Simple projects without labels only.
1
9
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3
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5
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8
9
1
2 3 4 5 6 7
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