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5.7.1
PDO mapping
The format of the Transmit PDOs between the master and the encoder must be
harmonized by means of socalled PDO mapping. The process data can be arranged
as required in the PDO message. For this purpose the address (that is the index and
subindex) from the object directory as well as the size (number of bits) are entered in
the mapping object
, ff.
Example:
Object 1A00h contains the following objects by default:
•
6004.00h – Position Value
•
2010.01h – Device Status Word, S_STAT-A
•
2010.02h – Device Status Word, S_STAT-B
The contents of the objects are transmitted in the Transmit PDO.
Table 30: Example for a Transmit PDO
COB-ID
Data
0180h +
Node-ID
00
00
00
01
00
00
00
00
Position value = 1
No error
No error
5.7.2
PDO data transmission
Bus load
Please note:
•
The more PDOs and the more often these PDOs are sent, the higher the bus load
in the CANopen network.
•
The higher the baud rate in the CANopen network, the lower the bus load.
•
The longer the cables used, the lower the possible baud rate.
For optimal communication a compromise therefore needs to be found between all
three factors mentioned.
If a Transmit PDO is not used, it should be deactivated. For this purpose set bit 31 to 1
in subindex .1 of the related object 180xh.
The PDOs can be transmitted cyclically or acyclically. This aspect is defined by the
objects 180xh and the transmission type defined in their subindex .02.
Table 31: Example for the communication parameters
Object
Subin‐
dex
Designation
Data values
180xh
Communication
Parameter for the
1st Transmit PDO
-
.0
Number of
entries
5
.1
COB-ID
000 Node ID
INTEGRATION IN CANOPEN
5
8016869/1EF3/2021-12-08 | SICK
O P E R A T I N G I N S T R U C T I O N S | AHS/AHM36 CANopen
AHS/AHM36 CANopen Inox
31
Subject to change without notice