Hitachi SJ2-CO instruction manual PDOProcess Data Object

CHAPTER5 CANOPEN COMMUNICATION FUNCTION

5.1.2 PDO(Process Data Object)

The real-time data transfer is using the PDOs.

There are two kinds of PDO transmission modes. One is a synchronization (SYNC), the other is

asynchronization message (Remotely Request, Event Driven, Timer Driven).

These PDO services use the push / pull models. The PDOs have Transmit-PDOs (maximum data size is 8

bytes) and Receive-PDOs (maximum data size is 8 bytes). These data type and these mapping are

defined by the Object Dictionary.

The following table is the PDO parameter indexes, the data types and the objects.

Index

1400h

1401h

1402h

1403h

1600h

1601h

1602h

1603h

1800h

1801h

1802h

1803h

1A00h

1A01h

1A02h

1A03h

Type

20h

20h

20h

20h

21h

21h

21h

21h

20h

20h

10h

20h

21h

21h

21h

21h

Object

1st receive PDO communication parameter

2nd receive PDO communication parameter

3rd receive PDO communication parameter

4th receive PDO communication parameter

1st receive PDO mapping parameter

2nd receive PDO mapping parameter

3rd receive PDO mapping parameter

4th receive PDO mapping parameter

1st transmit PDO communication parameter

2nd transmit PDO communication parameter

3rd transmit PDO communication parameter

4th transmit PDO communication parameter

1st transmit PDO mapping parameter

2nd transmit PDO mapping parameter

3rd transmit PDO mapping parameter

4th transmit PDO mapping parameter

Notes

Data type “20h” is a record, which defines the PDO communication parameter, and it is of the following

format:

Sub-Index	Type	Meaning	Notes
0h	UNSIGNED8	Number of supported entries in the	Default: 2
		record
1h	UNSIGNED32	COB-ID
2h	UNSIGNED8	transmit type	Default: 255
3h	UNSIGNED16	inhibit time	TPDO only
4h	UNSIGNED8	CMS priority group	Default: 3

Data type “21h” is a record, which defines the PDO mapping parameter and it is of the following

format:

Sub-Index	Type		Meaning			Notes
0h	UNSIGNED8	Number of supported entries in the				Default: 2
		record
		Structure consisting		of	mapped
1h		object index	(16 bit),	sub-index (8
		bits) and object data length in bits.
or	UNSIGNED32
		For example	“20010010h”		defines
1h, 2h
		object “2001h”, sub-index “0h”, and
		data length of16 bits (=word).

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