Hub / Switch implementation in the NetX
Hello,
We would like to use NetX 5 hub/switch fonctionality for Powerlink and for Profinet RT protocol.
In order to compare NetX 5 performances to the customer "cycle time" requirements, we are looking for theses folowing figures:
Powerlink:
- What is the latency time from Ethernet MII channel 1 to Ethernet MII channel II? (xMAC(1) --> xPEC(1) --> xMAC(2) --> xPEC(2) trip) http://fr.hilscher.com/files_design/8/netX5_Technical_Data_Reference_Guide_02.pdf - look at NetX 5 Block diagram: fig.1 on page 4
- What is the Jitter (worst case) for the same trip?
- Is BERT (Bit Error Rate) known?
Profinet RT:
- Same questions for Profinet configuration (Switch mode instead of hub)
Thank you,
Best Regards
Baptiste
Hi Andreas,
Thank you for your quick reply.
We would like to design a product (with netX 5 devices) to insert an optical section in the main Ethernet RT copper network:
We don't already know which interface wil be used to connect the HOST CPU, but will probably choose the fastest. We don't need to process a big amount of data, NetX will be mainly used for its embedeed hub/switch, to forward data from channel 1 to channel 2.
Do you mean that we need to define "interface" and CPU to know "forward latency", "jitter" and BERT of NetX 5 ?
We would like to specify estimated product performances (Latency, Jitter and BERT) to our customer before starting the design because we would like to know if NetX 5 could match to customer requirements (Round trip delay and reliability).
If you can't answer to my questions, we may plan to buy and make a pre-study with NetX 5 Evaluation Board (NXEB 5) and define performances with netAnalyser. Could you tell me if NXEB 5 could work in "stand alone" mode (without HOST CPU) as a simple forwarding Ethernet data (Hub/Switch function)?
Thank you,
Regards
Baptiste
Andreas Jacob
Hilscher Gesellschaft fuer Systemautomation mbH
Hi Baptiste,
thx for your drawing. Your application is still not clear for me. 2 x netX5 + 2 x HOST-CPU. I understand that you can not purplish and explain all the details of your application. (I do not understand the part with the fiber optics). From my point of view (without the knowledge of your application) this can be handled with only one netX5. On each channel is the customer network connected and the netX5 will forward the frames.
If you will use the faster interface to your HOST-CPU then you have to use the parallel DPM of the netX.
The netX5 can not work standalone without a HOST CPU. If you are interested in a test equipment you should buy the bundle which is a NXEB5 board and a NXHX50 as HOST.
latency", "jitter" and BERT of NetX 5 ?
Yes, because the access times are different for the available interfaces.
If I am honest, I still do not know what is meant by "BERT". Maybe you can teach me this feature.
THX.
Regards
AJ
Andreas,
We would like to develop something like PEAK product (PCAN-LWL) http://www.peak-system.com/Product-Details.49+M5b56929dba7.0.html?&L=1&tx_commerce_pi1[catUid]=6&tx_commerce_pi1[showUid]=22 , but for Real-Time Ethernet (instead of CAN) (Note that we are absolutly not in competition with peak; It is just a illustration example).
That's why I would like to uses 2 NetX, one on each sides of the optical fiber. Our goal is to make something deterministic (match with real time requirements) and invisible for customer network nodes.
BERT is "Bit Error Rate Tester" (sorry to use this Acronym). Actually, I would like to know NetX BER (which is mesured with BERT).
I hope that these explanations help you to more understand my application and then help you to give me information about performances of NetX (5 / 50) and the best Hilscher architecture to use.
Thank you
Baptiste
Andreas Jacob
Hilscher Gesellschaft fuer Systemautomation mbH
Hi Baptiste,
the used Broadcom PHY of our netX5 board does not support fiber-optic mode. To use FO you can take the Intel LXT973 (the new name of it is now CORTINA), but in that case you have to take care, that link, activity and duplex is connected in the right way to the xMAC.
Please keep in your mind that all netX chips supports only 100 Mbit in case of the HUB functionality.
Regarding your BERT request I have currently no values available.
Maybe it would be a good idea to get directly in contact with the Hilscher guy's. In that case you can tell them in more details about your project.
Thank You Andreas,
You are right, I'll ask Hilscher guy to get more information. I already have contacts with Hilscher France.
Don't you work for Hilscher? I Thought that yes
Andreas Jacob
Hilscher Gesellschaft fuer Systemautomation mbH
Don't you work for Hilscher? I Thought that yes
pssst...... maybe ;-)
Andreas Jacob
Hilscher Gesellschaft fuer Systemautomation mbH
Hi Baptiste,
it would be very helpful to know, which interface of the netX5 will be used to connect the HOST CPU. You can do it via a serial SPI connection or via a parallel memory connection. In case of the parallel connection is the used mode (8/16/32) also needed to know. Both interfaces have different timings.
Further more is the needed amount of process data's very important for your questions.
Please keep in your mind, that the netX5 does not include the PHYs and you only get the HAL code for it, which includes the communication layer up layer 2.
Maybe the netX50 would be the better solution (included PHYs, ...). But this is just an idea, because I do not know your application ;-)
Regards
AJ