CANopen communication
©
TR-Electronic GmbH 2007, All Rights Reserved
Printed in the Federal Republic of Germany
Page 154 of 260
TR - EMO - BA - DGB - 0013 - 00
05/16/2007
4.2.2.2 PDO (Process Data Object), SYNC (synchronization)
With a special message, the
SYNC message
, a so-called
SYNC Producer
can reach
all nodes and thus synchronize the message exchange.
encoTRive is a SYNC Consumer, so can only receive SYNC messages and react
to them.
A CANopen slave goes into "
PRE-OPERATIONAL"
state after switch-on. SDOs, but
not PDOs, may be transmitted in this status, and it is possible to configure PDOs
using SDOs. In the case of PDOs, the entire user data range of the CAN message
(8 bytes) can be used for the transmission of
parameter values
.
encoTRive supports up to six PDOs in each transmission direction.
The structure and contents that are transported with a PDO are defined with special
parameters, the
PDO Mapping Parameters
Figure 6: PDO Mapping Parameters
This so-called
PDO Mapping
specifies which parameters are transmitted in a PDO, in
which sequence. Figure 6 shows the mapping for Receive PDO 1 (RPDO1) and
Receive PDO 2 (RPDO2) from the viewpoint of the drive: Only object 0x6040 (control
word) is transmitted in RPDO1. RPDO2 consists of object
0x6040
and also of object
0x607A
(target position).