Pdo Mappings - Omron NX-ECC201 User Manual

8 EtherCAT Communications
8-4-2

PDO Mappings

PDO mapping objects contain the I/O data for the EtherCAT Slave Terminals. PDO mapping objects for
the RxPDOs are managed in the object dictionary from indexes 1600 to 17FF hex, and for the TxPDOs
from indexes 1A00 to 1BFF hex.
PDO Mapping Scheme in EtherCAT
The PDO mapping scheme in EtherCAT is described below.
Three application objects (objects A, B, and D) are allocated to the PDO (name: PDO_1) at index 1ZZZ
hex.
As described here, PDO mapping shows how application objects are assigned to PDOs.
Indexes and subindexes are also assigned to application objects.
Object Dictionary
Index
01 hex
1ZZZ hex
02 hex
03 hex
6TTT hex TT hex
UU hex
6UUU hex
VV hex
6VVV hex
6YYY hex
YY hex
6ZZZ hex
ZZ hex
PDO Mapping with EtherCAT Slave Terminals
An EtherCAT Slave Terminal has PDOs for the EtherCAT Coupler Unit and each NX Unit.
Application objects are assigned by default to the PDOs for each Unit.
The following diagram shows a specific example for one of the PDOs in an EtherCAT Coupler Unit.
Object Dictionary
Index
1 BFF hex
2001 hex
*1. This is expressed as 0x2001:01 on the Sysmac Studio.
8 - 6
Sub-
Object contents
index
6TTT hex TT hex 8
6UUU hex UU hex
8
6YYY hex YY hex 16
PDO-Length: 32 bits
Object A
Object B
Object C
Object D
Object E
Sub-
Object contents
index
01 hex 2001 hex 01 hex *1
PDO-Length: 8 bits
01 hex
Sysmac error status
PDO_1 Object A Object B
8
512th transmit PDO mapping
NX-series EtherCAT Coupler Unit User's Manual (W519)
Object D
Sysmac error status