Operating Instructions
Chapter
6
Flexi Soft Gateways
8012664/XB29/2013-06-11
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
143
Subject to change without notice
Fieldbus gateways
6.2.8
PDO communication
Process data objects (PDOs) are the real time objects of the CANopen fieldbus. They are
sent without protocol overhead, i.e. no confirmation is sent from the receiver.
The FX0-GCAN provides four transmit process data objects (TxPDO) containing the ope-
rational data to be sent into the network and four receive process data objects (RxPDO)
containing the operational data received from the network.
CANopen objects are addressed via 11-bit CAN identifiers. As a default, the used CAN
identifier for each object derives from the object type and the configured CANopen device
address. The CAN identifiers used for the PDOs can be changed using the SDOs 1400 to
1403 for the RxPDOs and SDOs 1800 to 1803 for the TxPDOs (“PDO linking”).
Each process data object contains 8 bytes.
The contents of the process data objects are freely selectable, but are preconfigured in
the Flexi Soft Designer configuration software as follows:
PDO#1
PDO#2
PDO#3
PDO#4
Input data set 1
Input data set 2
Input data set 3
Input data set 4
Byte 0
Logic result 0
Input values
module 5
Output values
module 1
Output values
module 9
Byte 1
Logic result 1
Input values
module 6
Output values
module 2
Output values
module 10
Byte 2
Logic result 2
Input values
module 7
Output values
module 3
Output values
module 11
Byte 3
Logic result 3
Input values
module 8
Output values
module 4
Output values
module 12
Byte 4
Input values
module 1
Input values
module 9
Output values
module 5
Gateway direct output
values 0
Byte 5
Input values
module 2
Input values
module 10
Output values
module 6
Gateway direct output
values 1
Byte 6
Input values
module 3
Input values
module 11
Output values
module 7
Gateway direct output
values 2
Byte 7
Input values
module 4
Input values
module 12
Output values
module 8
Gateway direct output
values 3
For detailed information about the content of the process image please see section 3.3
“Data transmitted into the network (input data sets)” on page 14.
For further information on how to configure the process image, see chapter 7 “Layout and
content of the process image” on page 173 and the Flexi Soft Designer operating instruc-
tions (SICK part no. 8012998).
The process data can also be written and read using service data objects SDO 6000
and SDO 6200 (see section 6.2.9 “SDO communication” on page 145). The simple SDO
access is recommended for diagnostic purposes. In normal operation the faster PDO
communication should be used.
After startup or after a configuration change has been performed (either via the
CANopen master or via the Flexi Soft Designer), the CANopen gateway’s MS LED flashes
red/green until an initial transmit/receive PDO or SDO 6000/SDO 6200 data exchange
on the CANopen network has happened.
Notes
Tab. 110: Default content of
the transmit process data
objects (TxPDOs) of the
FX0
>
GCAN
Notes