AM6442: No of slaves in EtherCAT and Profinet

Hello Jithesh,

Jithesh Balan said:

Just want to know how many slaves we can connect in EtherCAT, Profinet , Profibus and modbus network if the master is AM6442 based gateway. Did you done any case study or testing regarding this? Any information will be helpful. 

The answer to "how many slaves can be connected in EtherCAT, Profinet, Profibus, modbus for an AM64x master" is quite subjective. First of all, for EtherCAT, key performance indicators such EtherCAT cycle time and jitter of the EtherCAT frame can be influenced by the number of subdevices/slaves that are connected (typically, more subdevices means larger cycle time required to not miss the cycle time deadline). The requirement for cycle time can vary depending on your application as well.

Can you explain more about what sort of key performance requirements you are looking for? Additionally, are you asking about EtherCAT, Profinet, Profibus, and modbus separately (i.e. the performance of using AM6442 based gateway in a EtherCAT network, OR Profinet network, OR Profibus network, and not all three protocols running together in the same network with the AM6442 as a master)?

For EtherCAT, we have done some benchmarking on what is achievable in terms of cycle time and jitter with 11 subdevices (Beckhoff) connected to a TI AM64x EVM as running a CODESYS EtherCAT Master. Additionally, through other EtherCAT Master stacks (i.e. IBV EtherCAT Master), it has been proven that at least 23 subdevices can be supported with a cycle time as low as 100us. Please see this FAQ for more information about TI Processors running an EtherCAT Master stack (including benchmarking app notes and one-pagers): https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1424136/faq-how-to-setup-an-ethercat-network-using-ti-processors 

-Daolin

Hi Daolin,

Thank you for the quick reply. The benchmarking information of ethercat was very help ful . similarly we require the details of profinet, profibus, modbus, CAN also (seperately).

are you asking about EtherCAT, Profinet, Profibus, and modbus separately (i.e. the performance of using AM6442 based gateway in a EtherCAT network, OR Profinet network, OR Profibus network, and not all three protocols running together in the same network with the AM6442 as a master)? >> Yes, seperate details needed, we have all these interfaces in our gateway design. so what all are the details available with you, please share that. The ultimate question is , in practical case how many sub devices are able to connect in all these interfaces. i know the no of sub devices is depending on cycle time , jitter etc, Just want to know, in your testing / validation, how may devices was able to connect.? Any information will be helpful. Thanks in advance.

Hi Daolin -

 to add to your comment "...' for an AM64x master 'is quite subjective." - if the EtherCAT bus is optionally supporting redundancy, that may require 2 EtherCAT ports if one run the EtherCAT slaves back thru a ring topology to an AM6442 EtherCAT master.

later, Jim 

Hi Jithesh, 

Jithesh Balan said:

The ultimate question is , in practical case how many sub devices are able to connect in all these interfaces. i know the no of sub devices is depending on cycle time , jitter etc, Just want to know, in your testing / validation, how may devices was able to connect.? Any information will be helpful.

Jithesh Balan said:

similarly we require the details of profinet, profibus, modbus, CAN also (seperately).

To answer this question for the protocols other than EtherCAT, I will have to redirect this thread to a team member who has the right expertise on the other protocols (Profinet, Profibus, Modbus, etc).

Please expect a delay in response due to redirecting the thread.

-Daolin

Hi Daolin, Thanks for the support, it will be very helpful.

Hello Jithesh,

The performance of the tests will depend significantly on the stack implementation and other IO communication parameters like cycle time and DHT. If possible, could you let us know whether you have the Master stack enabled on AM64x with any stack partner?

Currently we have not ran any tests on AM64x and hence do not have the details on the benchmarking. However, I will check with the team internally and get back to you soon.

Jithesh Balan said:

The benchmarking information of ethercat was very help ful . similarly we require the details of profinet, profibus, modbus, CAN also (seperately).

Regarding other protocols, we do not support profibus and modbus protocols on AM64x.

Regards,
Laxman

For etherCAT we are using SOEM (open source) stack for master and TI stack for slave

Hi Jithesh,

Could you also mention which stack you are using for PROFINET master?

Regards,
Laxman

Hi Jithesh,

Currently we have do not have any benchmarking data on PROFINET master. Could you contact and check with the stack partner for the feature list and benchmarking results?

Regards,
Laxman 

Ya that i can check

Hi Jithesh,

Thank you for the prompt reply.
Do you have any other queries on this topic? 

Regards,
Laxman