03-19-2012 11:56 AM
Hi,
I am using IVI switch exe in my sequence to switch (Multiplexer and Relays), but it is really slow. Is there any other APIs to switch multiplexers and relays.
Thanks for the help.
03-19-2012 06:27 PM
Yes.
Use IVI Switch Step Type
Use Switch Executive with the Switching step property
Use LabVIEW VIs to call NI-SWITCH
03-20-2012 07:12 AM
Thanks for the response.
That's what I am using and it is very slow.
IVI teststep from NI is very slow. Is there any solution without using NI switching?
NI switching is not optimized and it is not suitable for all applications.
03-20-2012 07:22 AM
@LV2010 wrote:
[..]NI switching is not optimized [..]
What makes you think that? Are there any references which do proof this (daring) claim?
What hardware are you using?
What performance are you looking for vs. what are you currently seeing?
What is the purpose of the application you are implementing?
Without further information about status quo and quo vadis, we cannot provide more help....
Norbert
03-20-2012 07:27 AM
Thanks for the reply.
I am using NI 2576 Multiplexer card and It takes 1 to 2 seconds to switch one connection.
Because of that it is increasing my test time from 3 mins to 4.5 mins.
I tested another mulitplexer with different verndor it takes less than 100 ms.
03-20-2012 07:45 AM
1-2 seconds really seems unbelievable high. Never seen such high switching times with NI switches.
So there are several questions:
- How do you configure the IVI steps?
- Do you have tracing enabled? If so, how fast?
- When accessing the 2576 with the Switch Soft Frontpanel: How long does a switch process take there?
- How do you determine that it is the switching itself which takes that much time? Is it possible that you talk about the time consisting of Switching&Data Acquisition?
- Since the relays are electromechanic: Do you hear a single *click* or does the switching command result in multiple *clicks* you can hear?
Sidenote: The 2576 can get up to 146 cycles/s. This will not happen with software timed switching (IVI step type), but i would expect of several cycles per second.....
Norbert
03-20-2012 08:34 AM
Thanks for the reply. Here is the example sequence with test result. It took 4 seconds. Please let me know what I am doing wrong.
03-20-2012 08:48 AM
I can see that you are using NI Switch Executive (NI SE) in order to configure and manage your switch device.
Please enable the reporting for those two steps because i can imagine that the issue is created by the second step.
Why is that?
It seems that you are using the switch just as a matrix device, but it is a multiplexer. So NI SE has to make sure that the switch is working correctly within the constraints, the mux has. Additionally, we dont see any settings regarding "Tracing" in your station options, which could also explain the 4s execution time.
If neither helps, please provide your NI SE configuration.
Norbert
03-20-2012 08:56 AM
Here is my NI SE configuration.
03-20-2012 09:16 AM
I was not able to import your setting on my laptop successful such that i could perform some tests with a simulated 2576 device.
I assume that one reason could be that you configured the switch to be 2576/2-Wire Dual 32x1 Mux. But you have 64 channels. This does not fit together. Probably it is a sanity check which has to be done because of this missmatch which takes the long time....
Norbert