When you create a tag, you assign one of the possible data types to the tag. This data type depends on the type of data for which you would like to use the tag. Data Types Represent Values Such As numbers, real numbers, strings, character and Boolean values, Each data type has a specific range of values and operations that can be performed on it. All Data Type Have Some Reserved Memory For Storing Value In That Memory. When You Define Data Types To A Identifier, tag or variable, Data Type Reserved Space For Your Identifier tag or variable And Show How Values Are Interpreted To Identifier. Each Data Types Have Lower Limit And Upper Limit. If Value Above Or Below The Data Type Limit Than Value Not Stored In The Memory Space So Carefully Assign Data Type When You Make A Program. In this article we discuss Plc Standard Data Types.
wincc scada data types represent a specific value for specific tag. each tag in wincc scada have proper data type. each data types have diffrent memory area to store data in tag. in wincc scada tags data type are very important for communication, script(c and VBS), alarm system etc. following are data types in wincc scada -
signed /unsigned 8 bit to 32 bit are generally used in integer (numerical value).integer not store any value after decimal .
a Binary tag represent by binary data type. Binary tag corresponds to one bit. A binary tag can assume the values TRUE or "1" and FALSE or "0".The binary tag is stored as a byte on the system. Where true represent 1 or ON and false represent 0 or OFF. these data type used for on and off switches, output coil, alarm assignment, comparison instruction output, status of timer, counter, button, toggle button, status of motor etc.
The data type "Signed 8-bit value" has a length of one byte and a sign (plus or minus).The range of numbers is -128 to +127.
The data type "Unsigned 8-bit value" has a length of one byte and no sign. The range of numbers is 0 to 255.
The data type "Unsigned 16-bit value" has a length of two byte and no sign.The range of numbers is 0 to 65535.
The data type Signed 16-bit value has a length of two byte and a sign (plus or minus).The range of numbers is -32768 to +32767.
The data type Unsigned 32-bit value has a length of four byte and no sign.The range of numbers is 0 to 4294967295.
The data type Signed 32-bit value has a length of four byte and a sign (plus or minus).The range of numbers is -2147483647 to +2147483647.
You can create external and internal tags of the "Raw data type" type in the WinCC tag management. The format and the length of a raw data tag are not fixed. Its length can be in the range from 1 and 65535 bytes. It is either defined by the user or results from a specific application.
Raw data tags can be used in the following modules within WinCC:
Text tags are distinguished by the character set that has to be displayed, With the data type Text tag 8-bit character set each character displayed in this tag has a length of one byte. With the 8-bit character set.
With the data type Text tag 16-bit character set each character displayed in this tag has a length of two byte. You require a tag of this type to display the Unicode character set. During Text tag data type declare length of character. Length of character represents how much memory space should be reserved for the variable.
For process tags with the data type "Text tag 8-bit character set" or "Text tag 16-bit character set" you must specify the length of the text tag. A text tag that is required to accommodate 10 characters later must be ten long for the 8-bit character set and 20 long for the 16-bit character set.
The data type "Floating-point number 32-bit IEEE 754" has a length of four bytes and a sign (plus or minus).The data type "Floating-point number 32-bit IEEE 754" is also referred to as "Float".The number range is ±3.402823e±38.
The Floating-point number 64-bit IEEE 754 data type is eight bytes long and is signed (plus or minus).The Floating-point number 64-bit IEEE 754 data type is also referred to as Double.The number range is +-1.79769313486231e+308.