Omron NX-ECC201, User Manual, Page: 166 / 406

8 EtherCAT Communications
8 - 6 NX-series EtherCAT Coupler Unit User’s Manual (W519)
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.
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.
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.
8-4-2 PDO Mappings
PDO Mapping Scheme in EtherCAT
PDO Mapping with EtherCAT Slave Terminals
8
16
8
Object B
Object C
Object A
PDO_1
Object E
Object D
Object A Object B Object D
Index
02 hex
03 hex
01 hex
Sub-
index
UU hex
VV hex
TT hex
ZZ hex
YY hex
Object contents
Mapping object
Object Dictionary
Application object
1ZZZ hex
6TTT hex
6UUU hex
6VVV hex
6YYY hex
6ZZZ hex
6UUU hex UU hex
6TTT hex TT hex
6YYY hex YY hex
PDO-Length: 32 bits
2001 hex
01 hex
01 hex
2001 hex 01 hex *1
Index
Sub-
index
Object contents
8
Sysmac error status
Object Dictionary
1 BFF hex
*1. This is expressed as 0x2001:01 on the Sysmac Studio.
Sysmac error status
512th transmit PDO mapping
PDO-Length: 8 bits
Mapping
object
Application
object