Does EtherCAT Slaves Can Have Static Address?

Question

We develop a new machine with many motors connected over EtherCAT to the main controller. . I wish to set each motor with a specific address

I saw that I can set EtherCAT ID in the motor Software, number from 1 to 32766 (32767 let the master allocates the address)

But I'm a bit confused regarding this option because the documentation only have details regarding options where the master allocates the address

Is "Configured Station Alias" is the static address assigned by the slave?

Does the slave contain two address? one set by Master and one optionally set by the slave?

Is there advantages, like speed or reliability, to allow the Master to set the slaves addresses?

Is all, or most, EtherCAT devices (Salves and Maters) include IP Address?

For Example Beckhoff EtherCAT Documentation: http://www.manualsdir.com/manuals/757430/beckhoff-ethercat-technology-section-i.html?page=27

EtherCAT Packet diagram:

Answer 1

EtherCAT slaves can be addressed in several different ways:

• Position addressing: The slave is addressed by their position in the network.
• Station alias: Address which the master can assign to a slave, by writing it to non-volatile memory in the slave.
• Device ID: Some EtherCAT slaves have the option to physically set an address on the slave. Often via a DIP switch. Most EtherCAT slaves do not support this.

These are the three addressing modes which an EtherCAT user comes into contact with.

Under the hood there are two more, for technical reasons:

• Node addressing
• Logical addressing

These are run-time addressing managed by the EtherCAT master. The EtherCAT master basically uses the addressing (position, Station alias, Device ID) selected by the user, and translates it to "Node addressing" and "logical addressing" at runtime.

EtherCAT slaves typically do not have IP addresses or MAC addresses.

Answer 2

Each of the EtherCAT Coupler and its Terminals have Vendor ID, Product Code and Revision number. I don't know what do you mean by referring to IP address here. Also PDO entries if you want to write data or read data to/ from a very specific position.

No they don't have two IP addresses.

As many number of terminals can be connected to a EtherCAT Coupler, each of the Coupler and terminal information (in fact, how the bus is configured has to be know by the EtherCAT Master before hand). So there might be multiple addresses of each terminal connected to the coupler.

Hope I did not confuse you.

Regards.