Tags in Citect SCADA hold data values that can be defined as one of the following data types.
|
Data Type |
Variable |
Size |
Allowed Values |
|---|---|---|---|
|
BCD |
Binary- Coded Decimal |
2 bytes |
0 to 9,999 |
|
BYTE |
Byte |
1 byte |
0 to 255 |
|
DIGITAL |
Digital |
1 bit or 1 byte |
0 or 1 |
|
INT |
Integer |
2 bytes |
-32,768 to 32,767 |
|
UINT |
Unsigned Integer |
2 bytes |
0 to 65,535 |
|
LONG |
Long Integer |
4 bytes |
-2,147,483,648 to 2,147,483,647 |
|
ULONG |
Unsigned Long Integer |
4 bytes |
0 to 4,294,967,295 |
|
LONGBCD |
Long Binary- Coded Decimal |
4 bytes |
0 to 99,999,999 |
|
REAL |
Floating Point |
4 bytes |
-3.4E38 to 3.4E38 |
|
STRING |
String |
256 bytes (maximum) |
ASCII (null terminated) Note: Non printable characters within string tag values will be substituted with spaces. For example, string [ 0x01, 0x41, 0x10, 0x42 ] will appear as "A B" so cache loading continues to operate. |
While numeric variables are more common, some I/O devices also support ASCII strings. You can use strings to store text data (for example, from a bar code reader). All strings needs to be NULL-terminated in the I/O device , as Citect SCADA uses the NULL character to check for the end of a string. If no NULL character is present, Citect SCADA reads (and displays) any extra characters in memory, after the end of the string.
When you are using a disk I/O device, you can also specify a string data type for storage of recipes, or for operator display information.
Not every I/O device supports strings. However, if your I/O device does support integer data types, Citect SCADA can use these integer registers to store ASCII strings in your I/O device. Citect SCADA strings can only be stored in contiguous blocks (consecutive registers), and are stored as an array.
A Cicode variable of INT data type can be used to store Tag data types: BCD, BYTE, DIGITAL, INT, UINT, LONG, ULONG and LONGBCD.
A Cicode variable of the
Tag values can be used with the
Published June 2018