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)
Significance2726252423222120
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)
SignificanceVZE8E7E6E5E4E3E2
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)
SignificanceM7M6M5M4M3M2M1M0
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
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