Operation
27
Numerical Formats and Displays
The controllers support REAL, INT, DINT (TIME) and BOOLean
data.
The following tables give an overview of the support value ranges
and the memory requirements for data transfer via PROFIBUS-
DP:-
Data type
Value range
Required memory
[bytes]
REAL
-1,175.494.35E-38
...
0.0
...
3,402.823.47E+39
4
INT
-32.768
...
0
...
32.767
2
DINT
-2.147.483.647
...
0
...
2.147.483.647
4
TIME
T#0s...T#99h59m59s
4
BOOL
FALSE (0 or 0x00) and
TRUE (255 or 0xFF)
1
The format for REAL numbers used for the devices corresponds
to the IEEE format. - -The diagram below shows this 32-bit format.
---
With data types occupying more than one byte the order in which
these data bytes are to be transmitted on the bus can be defined.
This is done by the fourth byte of the "User_Prm_Data". Which of
the possible options is to be used depends on how the data is
further processed by the Class 1 PROFIBUS DP master. Please
refer to the respective master documentation for details. -----
The following illustrations give an overview of the order in which
the data types are represented and transmitted in dependence of
the fourth byte of "User_Prm_Data".-
Data type INT (Integer)
MSB
LSB
Bit number
15
14
13
12
11
10
9
8
Byte
1
(High)
Significance 2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
Bit number
7
6
5
4
3
2
1
0
Byte 2 (Low)
Significance 27
26
25
24
23
22
21
20
User_Prm_Data:
4th. byte = 0 or 0x00: Byte 2 sent before byte 1
4th byte = 255 or 0xFF: Byte 1 sent before Byte 2
Data type DINT (Double-Integer) and TIME
MSB
LSB
Bit number
31
30
29
28
27
26
25
24
Byte
1
(High)
Significance 2
31
2
30
2
29
2
28
2
27
2
26
2
25
2
24
Bit number
23
22
21
20
19
18
17
16
Byte 2
Significance 2
23
2
22
2
21
2
20
2
19
2
18
2
17
2
16
Bit number
15
14
13
12
11
10
9
8
Byte 3
Significance 2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
Bit number
7
6
5
4
3
2
1
0
Byte 4 (Low)
Significance 2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
User_Prm_Data:
4th. byte = 0 or 0x00:
Byte 4 sent before Byte 3 before Byte 2 before Byte 1
4th. byte = 255 or 0xFF:
Byte 1 sent before Byte 2 before Byte 3 before Byte 4
Data type REAL (Float)
MSB
LSB
Bit number
31
30
29
28
27
26
25
24
Byte
1
(High)
Significance VZ
E8
E7
E6
E5
E4
E3
E2
Bit number
23
22
21
20
19
18
17
16
Byte 2
Significance E1
M22 M21 M20 M19
M18
M17 M16
Bit number
15
14
13
12
11
10
9
8
Byte 3
Significance M15
M14 M13 M12 M11
M10
M9
M8
Bit number
7
6
5
4
3
2
1
0
Byte 4 (Low)
Significance M7
M6
M5
M4
M3
M2
M1
M0
VZ = Sign bit
E.. = Exponent bit
M.. = Mantissa bit
User_Prm_Data:
4th. byte = 0 or 0x00:
Byte 4 sent before Byte 3 before Byte 2 before Byte 1
4th. byte = 255 or 0xFF:
Byte 1 sent before Byte 2 before Byte 3 before Byte 4