Programming manual SCU-series
HB-37500-820-10-12F-EN SCU Programming manual
Page 18 of 252
Status: 19.03.2021
3. Requirements
3.1. SCU unit
The SCU is a Master unit for FSoE communication to read encoder data and switching statuses of
external Slave units to implement safety functions.
The SCU can send, receive and process safe data via FSoE and unsafe data via EtherCAT. In the
EtherCAT network, the SCU only functions as Slave.
3.2. Network connection
3.2.1. EtherCAT
The EtherCAT network consists of one Master and a certain number of Slaves.
Data transfer is carried out via Ethernet connections existing between the EtherCAT Master and
every participant, and, as a rule, running serially from participant to participant. Via these
connections Ethernet-Frames are sent. Every network participant ´must first read the received
data, filter the data addressed to it, and insert the exit data into the Frame. Having passed all
Slaves, the Frame is sent back to the EtherCAT Master.
As thus every participant can influence the transfer of a message, the network must be exactly
defined or specified. This specification is carried out via the ESI files, fixing the participants and
their properties.
Data transfer is always initiated by the Master.
–
Data transfer is carried out in the EtherCAT
network with a transfer time of at best a few µs.
Figure 1: EtherCAT
network
Master
In Out
In Out
Slave
In Out
Slave
In Out
Slave
In Out
Slave
