EtherCAT Communication
Parameter Description
Tx Counter Gateway
The Tx counter is increased by the Gateway to indicate that the CAN
Tx messages were copied from the output data to the local CAN send
queue (see Figure 26).
Rx Counter Gateway
The Rx counter is increased by the Gateway every time when new
CAN Rx data arrived and the
Rx Counter Gateway
(6000
h
, sub-index
02) is identical with
Rx Counter Application
(7000
h
, sub-index02). This
indicates that new Rx data has been written into the process input data
(see Figure 23).
Number of Rx Messages
Contains the number of CAN Rx messages in the following input data
when the RX Counter was increased (1…m-4).
Tx Transaction Number
Contains the transaction number of the last sent Tx (see Figure 24)
Rx Message 1...(m-4)
1. to (m-4). CAN Rx message
The message is composed of the following components:
Bit 0-3:
CAN message length (0…8 bytes)
Bit 4:
RTR Bit
Bit 5-15: CAN Identifier (11-bit CAN ID)
Bit 16-79: CAN-Rx data
Figure 24:
Formatting of the CAN data in the EtherCAT process image
(11-bit Rx and Tx)
CAN-EtherCAT
Manual • Doc. No.: C.2922.21 / Rev. 1.4
Page 39 of 92