4.5.3
Checksum calculation
Overview
When exchanging safety-related data via SRDOs, it is necessary to calculate a check‐
sum.
The object 0x13FF contains the checksums of the SRDOs.
Example
In the following example, the CRC-16-CCITT (polynomial 1021h) checksum is calculated
for an RSRDO.
The checksum is calculated bytewise and begins with the respective low byte of the two
objects 1302h and 1382h.
Table 42: Example: CRC-16-CCITT checksum calculation
Object
Subindex
Name
Size
Data
1302h
RSRDO communication parameters
01h
Information direction
1 byte
02h
02h
Refresh time
2 bytes
0032h
03h
tx: reserved
rx: SRVT
1 byte
14h
05h
COB-ID 1
4 bytes
00000111h
06h
COB-ID 2
4 bytes
00000112h
1382h
RSRDO mapping parameters
00h
Highest subindex
1 byte
04h
Subindex
1 byte
01h
01h
Application data 1
4 bytes
60100108h
Subindex
1 byte
02h
02h
Inverted application
data 1
4 bytes
60110108h
Subindex
1 byte
03h
03h
Application data 2
4 bytes
60100208h
Subindex
1 byte
04h
04h
Inverted application
data 2
4 bytes
60110208h
The following data bytes are used for the checksum calculation:
•
0x02 0x32 0x00 0x14 0x11 0x01 0x00 0x00 0x12 0x01 0x00 0x00 0x04 0x01
0x08 0x01 0x10 0x60 0x02 0x08 0x01 0x11 0x60 0x03 0x08 0x02 0x10 0x60
0x04 0x08 0x02 0x11 0x60
The checksum is 4370h.
4.5.4
Object directory
Standard objects
The following table describes only those objects that do not have a fixed definition in
the CANopen standard.
Table 43: Object directory (standard objects)
Object
Sub
Access Object name
Default value Type
Description
0x1000 0x00 RO
Device Type
0
UNSIGNED32 No device profile
supported
4
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Subject to change without notice