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.
16 CANopen for S300/S700
CANopen communication profile 11/2018 Kollmorgen
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