User Manual

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4.4 Memory areas, addressing and data types
Easy Book
60 Manual, 03/2014, A5E02486774-AF
4.4.1
Data types supported by the S7-1200
Data types are used to specify both the size of a data element as well as how the data are to
be interpreted. Each instruction parameter supports at least one data type, and some
parameters support multiple data types. Hold the cursor over the parameter field of an
instruction to see which data types are supported for a given parameter.
Table 4- 3 Data types supported by the S7-1200
Data types
Description
Bit and bit-sequence
data types
• Bool is a Boolean or bit value.
• Byte is an 8-bit byte value.
• Word is a 16-bit value.
• DWord is a 32-bit double-word value.
Integer data types
• USInt (unsigned 8-bit integer) and SInt (signed 8-bit integer) are "short" integers (8 bits or 1
byte of memory) that can be signed or unsigned.
• UInt (unsigned 16-bit integer) and Int (signed 16-bit integer) are integers (16 bits or 1 word of
memory) that can be signed or unsigned.
• UDInt (unsigned 32-bit integer) and DInt (signed 32-bit integer) are double integers (32 bits or
1 double-word of memory) that can be signed or unsigned.
Real number data
types
• Real is a 32-bit Real number or floating-point value.
• LReal is a 64-bit Real number or floating-point value.
Date and time data
types
• Date is a 16-bit date value (similar to a UInt) that contains the number of days since January
1, 1990. The maximum date value is 65378 (16#FF62), which corresponds to December 31,
2168. All possible Date values are valid.
• DTL (date and time long) is a structure of 12 bytes that saves information on date and time in
a predefined structure.
– Year (UInt): 1970 to 2554
– Month (USInt): 1 to 12
– Day (USInt): 1 to 31
– Weekday (USInt): 1 (Sunday) to 7 (Saturday)
– Hours (USInt): 0 to 23
– Minutes (USInt): 0 to 59
– Seconds (USInt): 0 to 59
– Nanoseconds (UDInt): 0 to 999999999
• Time is a 32-bit IEC time value (similar to a Dint) that stores the number of milliseconds (from
0 to 24 days 20 hours 31 minutes 23 seconds and 647 ms). All possible Time values are
valid. Time values can be used for calculations, and negative times are possible.
• TOD (time of day) is a 32-bit time-of-day value (similar to a Dint) that contains the number of
milliseconds since midnight (from 0 to 86399999).
Character and string
data types
• Char is an 8-bit single character.
• String is a variable-length string of up to 254 characters.