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
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