650 Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Appendix A Common Attributes
Data Types
LINT Data Type Considerations
When using LINT data types, many limitations apply. A LINT data type cannot
be used in most instructions. Limitations are as follows:
• The LINT data type is not supported in Machine Edition. The LINT data
type is a 64-bit word; ME uses only 32-bit words.
• The LINT data type is not supported by HMIs.
• The LINT data type is not supported in most instructions.
When using LINT data types, consider the following descriptions when these
issues occur.
SINT or INT to DINT
For those instructions that convert SINT or INT values to DINT values, the
‘Operands’ sections in this manual identify the conversion method.
The following example shows the results of converting a value using sign-
extension and zero-fill.
LINTs can only be used with Move and Copy instructions.
They are used with the CST/WallClock Time attribute, time
synchronization and Add-On Instructions.You cannot Add,
Subtract, Multiply, or Divide this tag type.
How to Description
Move/copy two double-integer DINT values into
one LINT
Create a double integer array of two elements,
total of 64 bits (that is, DINT[2], which can then
be copied into one long integer.
Correct Date/Time Display error When a tag has a negative value, it cannot be
displayed as Date/Time. In the tag editor, check
whether the value is negative by changing the
style of the tag from Date/Time to Binary. When
the most significant bit (leftmost one) is 1, the
value is negative and therefore cannot be
displayed as a Date or Time.
This conversion method Converts data by placing
Sign-extension The value of the leftmost bit (the sign of the value) into each bit
position to the left of the existing bits until there are 32 bits.
Zero-fill Zeroes to the left of the existing bits until there are 32 bits.
This value 2#1111_1111_1111_1111 (-1)
Converts to this value
by sign-extension
2#1111_1111_1111_1111_1111_1111_1111_1111 (-1)
Converts to this value
by zero-fill
2#0000_0000_0000_0000_1111_1111_1111_1111 (65535)
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