User guide

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VTB USER GUIDE
6.9 Fixed Variables
The variables of type FIXED are allocated at a fixed address in the internal memory of the device which, unlike common
variables, doesn't change modifying the program. This type of variable simplifies the use of systems connected to an
external HOST (ex. PC). In fact using FIXED variables there will be no need to recompile the HOST application at each
change in VTB program.
FIXED variables are always GLOBAL that is visible in all page and in all tasks.
TYPE
DIMENSION
RANGE
BIT
1 bit
From 0 to 1
CHAR
8 bit signed
From –128 to +127
UCHAR
8 bit unsigned
From 0 to 255
INT
16 bit signed
From –32.768 to +32.767
UINT
16 bit unsigned
From 0 to 65.535
LONG
32 bit signed
From –2.147.483.648
to +2.147.483.647
FLOAT
64 bit (standard DOUBLE format IEEE 75)
From -1,79769313486232e308
to +1,79769313486232e308
The START address of FIXED area is:
NGM13 - NGMEVO Addr= 536874496
NG35 Addr= 1051648
NGQ - NGQx Addr = 8389632