Process Data Objects (Pdo); Structure Of Pdo Cob-Id Entry; Pdo Usage - Danfoss FC 300 Manual

FC 300 CANopen

Process Data Objects (PDO)

There are four read (receive) PDOs and four write (transmit) PDOs for the frequency converter.
Real-time process data is communicated using the PDOs.
The format of the structure is as follows:
PDO Communication Parameter Record
Index Sub-Index Field In PDO Communication Record
0020H 0H Number of supported entries in the record
1H COB-ID used by PDO
2H Transmission type
3H Inhibit time
4H CMS priority group
If the device supports the identifier distribution via DBT the value on sub-index 0H is 4, otherwise it is
2 (inhibit time not supported) or 3. The COB-ID at Index 20H, Sub-Index 1H is defined using data
type Unsigned32 in order to cater for 11-bit CAN Identifiers as well as for 29-bit CAN identifiers. The
entry has to be interpreted as defined in the following figure and table

Structure of PDO COB-ID entry

Unsigned32
MSB
bits
31
11-bit-ID 0/1
29-bit-ID 0/1
Description of PDO COB-ID entry
Bit number Value
0
31(MSB)
1
0
30
1
0
29
1
0
28-11
X
X
10-0 (LSB)
The PDO valid/not valid permits selection of PDOs to be used in the operational stage.
PDOs may be fully configured (e.g. by default) but not used, and therefore set to "not valid". Bits 29
and 30 may be static (not changeable), e.g. due to hardware restrictions, in which case no error is
signalled on the attempt to change them.

PDO Usage

The real-time data transfer is performed by means of "Process Data Objects (PDO)". PDOs are
represented by CMS objects of type "Stored-Event". Hence the transfer of PDOs is performed with no
protocol overhead.
32
30 29 28-11
0/1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0
0/1 1 29-bit Identifier
Meaning
PDO valid
PDO not valid
RTR allowed on this PDO
No RTR allowed on this PDO
11-bit ID (CAN 2.0A)
29-bit ID (CAN 2.0B)
If bit 29=0
If bit 29=1: bits 28-11 of 29-bit-COB-ID
Bits 10-0 of COB-ID
MG.33.J1.02 VER. 050301 – VLT is a registered Danfoss trademark
LSB
10-0
11-bit Identifier
Data Type
Unsigned8
Unsigned32
Unsigned8
Unsigned16
Unsigned8