NI Veristand via ASAM XIL - MAPort: Expected latency on write?

[Kristofer]

Hi

Starting to evaluate using NI Veristand(2018) via ASAM-XIL (MAPort) and did some initial performance tests reading and writing values to aliases in the Engine demo using Python.

My current setup is running python using the ASAM-XIL API on one computer and Veristand on another, connected via Wifi.

Read averages on 1-2ms, sometimes slower ~6ms, something that seems rather ok.

Write is in the range 30-60ms which to me seems very slow given that the network added latency part of it should be less than 1ms.

Is this what one can expect?  Is there a obvious reason on why(update loops in Veristand?)? Other experiences or ways to improve?

Best regards!

Kristofer

[Kristofer]

Found a parameter to modify, greatly improving the latency, changed the "Data rate" setting from default 15Hz to 250Hz (anything above 250Hz gave basically no difference)

Read went down roughly 25%

Write went down to around 15ms, which I still consider a bit high for the planned usage scenario.

Anyway to improve even more?

P.S: NOTE: I have not tried against a running real time engine yet, this hopefully improves the latency even more (but that is yet to be proven)

[JeremieRdg]

Hi Kristofer,

I'm experiencing the same issue with the latency of the MAPort.

Could you please provide more information about how to modify that "Data rate" setting you found ? Is it a setting of the MAPort ? How can I access it ?

I couldn't find anything about that setting in the ASAM XIL documentation.

Thank you for your help !

Best regards,

Jeremie

[Kristofer]

Hi Jeremie

You can find it in the veristand .sysdef file(XML).

/Kristofer

[JeremieRdg]

Got it. Works fine. 

I set it to 200Hz and I got something close to 5ms between two read values, which is consistent. 

Thank you very much ! 

Jeremie

[Kristofer]

Glad to be able to help out!

Would hope some one with insight and expertise could help out elaborating on possibilities to improve even more (maybe someone from NI?)

BTW: Can you please check what write performance you get and reply?

/Kristofer