Table of Contents
Advertisement
The number of display characters that are used to display a value varies. This variation is not
reflected in the number of bytes that are required to store the value in the S7-200 CPU
memory. In the CPU memory, two bytes are required to store a word value, and four bytes
are required to store a double word or a real (floating point) value.
Table D-1 shows you how many display characters are required for each display format and
the maximum number of display characters required for each format. For example, if you
know that the size of the value will never exceed three digits and will always be positive, then
the number of display characters required will always be less than the maximum values
given in Table D-1.
For real (floating point) numbers, the TD 200 uses up to 20 digits to represent the number.
(This includes the number of decimal places that were specified in the format word. See
Figure D-18.) If a number cannot be displayed within the number of digits available, the
TD 200 displays "eeeeee" for that value.
Table D-1
Value
Unsigned
Signed
Unsigned
Signed
Real
(Floating
(Floating
Point)
SIMATIC TD 200 Operator Interface
C79000-G7076-C205-04
Required Display Characters for Each Display Format
Number of Digits
Number of Display Characters
Size
to the Right of the
Decimal Point
0
1 to 4
Word
5
6
7
0
1 to 4
Word
5
6
7
0
DWord
1 to 7
0
DWord
1 to 7
0
DWord
DWord
1 to 7
TD 200 Parameters and Messages
Example
(maximum)
5
12345
6
1234.5 to 1.2345
7
0.12345
8
0.012345
9
0.0012345
6
–12345
7
–1234.5 to –1.2345
8
–0.12345
9
–0.012345
10
–0.0012345
10
1234567891
123456789.1 to
11
123.4567891
11
–1234567891
–123456789.1 to
12
–123.4567891
Up to 20
–1234567
Up to 20
12345.6 to 0.0123456
D-19
Advertisement
Table of Contents
