1 basic data types, 1 unsigned integer, 2 signed integer – BECKHOFF AX2000 CANopen communication profile User Manual
Page 17: 2 mixed data types, Basic data types, Mixed data types, Unsigned integer, Signed integer, Canopen communication profile
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3.3.1
Basic data types
3.3.1.1
Unsigned Integer
Data in the basic data type UNSIGNEDn define exclusively positive integers.
The value range is from 0 ... 2
n
-1. The bit sequence b = b
0
... b
n-1
defines the value
UNSIGNEDn(b) = b
n-1
2
n-1
+ ... + b
1
2
1
+ b
0
2
0
Example: the value 266 = 10A
h
is transmitted in the data type UNSIGNED16, in the form of two
octets (1
st
octet = 0A
h
, 2
nd
octet = 01
h
).
Transmission syntax for the data type UNSIGNEDn
Octet number
1.
2.
3.
4.
5.
6.
7.
8.
UNSIGNED8
b
7
..b
0
UNSIGNED16
b
7
..b
0
b
15
..b
8
UNSIGNED24
b
7
..b
0
b
15
..b
8
b
23
..b
16
UNSIGNED32
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
UNSIGNED40
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
b
39
..b
32
UNSIGNED48
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
b
39
..b
32
b
47
..b
40
UNSIGNED56
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
b
39
..b
32
b
47
..b
40
b
55
..b
48
UNSIGNED64
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
b
39
..b
32
b
47
..b
40
b
55
..b
48
b
63
..b
56
3.3.1.2
Signed Integer
Data in the basic data type INTEGERn define both positive and negative integers.
The value range is from -2
n-1
-1 ... 2
n-1
-1. The bit sequence b = b
0
..b
n-1
defines the value
INTEGERn(b) = b
n-2
2
n-2
+ ... + b
1
2
1
+ b
0
2
0
with b
n-1
= 0
Negative numbers are represented as 2’s complement, which means:
INTEGERn(b) = - INTEGERn(b) - 1 with b
n-1
= 1
Example: the value -266 = FEF6
h
is transmitted in the data type INTEGER16, in the form of two
octets (1
st
octet = F6
h
, 2
nd
octet = FE
h
).
Transmission syntax for the data type INTEGERn
Octet number
1.
2.
3.
4.
5.
6.
7.
8.
INTEGER8
b
7
..b
0
INTEGER16
b
7
..b
0
b
15
..b
8
INTEGER24
b
7
..b
0
b
15
..b
8
b
23
..b
16
INTEGER32
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
INTEGER40
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
b
39
..b
32
INTEGER48
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
b
39
..b
32
b
47
..b
40
INTEGER56
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
b
39
..b
32
b
47
..b
40
b
55
..b
48
INTEGER64
b
7
..b
0
b
15
..b
8
b
23
..b
16
b
31
..b
24
b
39
..b
32
b
47
..b
40
b
55
..b
48
b
63
..b
56
3.3.2
Mixed data types
Mixed data types combine basic data types (INTEGERn, UNSIGNEDn, REAL). Two types of mixed
data are distinguished:
l
STRUCT
This data type is composed of elements with different data types.
l
ARRAY
This data type is composed of elements of the same data type.
CANopen for AX2000/2500
17
BECKHOFF
07/2007
CANopen communication profile