Whether intended or not, I am receiving bad service

[Euler's_Identity]

Security measure??  I wasn't aware of it.  Sorry.

This will really be something if you can succeed where MultiSim's support has failed for two weeks now, especially if it's my error.

I would much rather MultiSim worked than deal with PSPICE etc.  MultiSim just seems to me to be more intuitive, more like you're building on a bench, ya know?

[lacy]

Well, I have looked at this. In my opinion it is definitely a software glitch. I have not been able to isolate for sure exactly what is causing the problem. For me, sometimes it works and sometimes it don't irreguardless of what I may try. I am still looking at it and have a few other thing I want to try, but if it is a software problem, then that would be in the hands of NI at that point.. I thought I would just post my thoughts on this for NI to read.

Have a Nice Day

[Euler's_Identity]

Lacy,

I appreciate your efforts on my behalf.  In response to what you've just said about a software problem, I'll give you my latest pet peave at work:

Ya think?!

(It's what I use when someone has stated the obvious, and, in your case, I mean no disrespect by it.)

At least the scope will give me something.

As far as the LF347 is concerned, I'm not really surprised.  The thing is I can't even trust the program to build my own models when the models don't work. 😞  I really feel for those who actually lose and have lost money due to this program.

My experience with this program, since 2000, has been bug after bug after bug.  In fact, I have no qualms about considering myself the perfect guinea pig, with respect to this program, even though not once have I done something original, design-wise.  I'm really considering just biting the bullet and shelling out for PSpiCE, even with all its esoterics.   There's a reason it's the most popular program, but man is it expensive!

[lacy]

I have an idea. Have you tried Switcher Cad II from Linear Technologies. It's free from their website. I don't think it compares to Multisim, but you might what to check it out if haven't already. This could save you a few bucks if it works for you.

I wish I could definitively say what it is that is causing your problem. Like I said, sometimes I get it to work and other times it crashes or returns errors. I am wondering if this has anything to do with digital components inside subcircuits. laProfe found if you use digital components with busses inside subcircuits it returns an error message and won't simulate. I am curious if this relates to your problem in some way.

Anyway, I am still trying. I am not making much progress ,but I am still working with it.

Have a nice day.

[Euler's_Identity]

Actually, PSPICE, like everything else was bought, so now it's Cadence/OrCAD.  It's the industry standard.  It costs a lot.  It costs a lot because it works, and it works because it was tested, and it was tested because the people testing it were paid to test it.  True, it isn't perfect, but for the most part it works.  Once they had a core working program, then they could build.  MultiSim never got that simple bit of logic, and I could swear that anyone who buys it is a beta tester who is paying to do MultiSim's job.
 
I'm tired of doing MultiSim's job.

.

[Euler's_Identity]

It's now September 6, 2007.

I began this thread AFTER I'd determined I had no other alternative because "ask an engineer" wasn't helping.

This thread began on August 22, 2007.

I have heard zero for days.

Is National Instruments even still working on getting a solution to me?

Personally, I say no.

No, I think they're stumped and would like me to just go away.

Their software doesn't work, and they don't know how to fix it without a redevelopment.

If I'm wrong, they sure haven't given me evidence otherwise.

[_user32]

Dear Euler's Identity,

I am the Business Development Manager at National Instruments for the Electronics Workbench.  I have researched this issue and I do believe the application engineers have attempted to get back to you with several work arounds that have seemed to correct the issue in version 10.0.1 and are waiting on a response from you to see if you have tried their suggestions.  If this is not the case, or you feel that you are still receiving poor service, I recommend that we take this offline and you can personally give me a call.  My cell phone is 207 415-7754.

The intent of these forums is to engage the user community and exchange ideas or recommend workarounds to benefit all.   Technically, without giving away the details in your circuit, let me add some value to this thread so that existing users can have some understanding of what this issue is and so that it can possibly have some benefit to all.  

The issue as seen by Eulers Identity has to do with a combination factors which results in the circuit schematic and its subsesquent simulation netlist to incorrectly load into the sim engine in Multisim.   The circuit in question uses many Hierarchical Blocks (representing specific chips/modules) with many digital logic gates and tristate gates within each block and also has many digital indicators (at the top level) to visualize the state of the digital logic as the circuit is simulating.   The specific issue (which does seem to be intermittent) seems to be with the embedded digital logic blocks - specifically the tristate gates and the probes located on the outside of the hierarchical blocks - which when used in this way or in some combination, sometimes cannot properly initialize themselves - ie the digital logic blocks and their respective tristate levels - do not correctly load.  This is an internal issue and we are working to resolve this.  The application engineer that you were speaking with said he did find a work around - simply by switching the type of digital probe that you are using seems to take care of the issue in v10.0.1 and he is waiting for you to confirm this work around he has sent back to you.

Also, looking at your circuit, it appears that you are trying to use hierarchical blocks to represent components - a better solution might be to develop a subcircuit model for the hierarchical block 'chips' that you are trying to create - since you use these frequently, a subcircuit model is a more robust modeling convention than a hierarchical block approach.   There is some detail on how to create digital level spice models - located here...

http://zone.ni.com/devzone/cda/tut/p/id/6369

Also, to address your concerns about our software process and your comparison against other simulators.   First I will add that I have used a variety of simulators, and even the more expensive ones all have issues - many cannot do digital and analog simulation that adds the layer of interactivity that Multisim does - especially when you are using a combination of digital and analog cosimulation (the tristates are forcing you into the analog domain).  Also I will say that you did unfortunately find a bug and we are working hard to correct this, however we have been actively using a formal software design and testing process to formerly validate our software releases.   However like all tool level software, there is no way to completely resolve all issues and unique customer use cases - however I do believe the overall concensus that I have been getting is that our customers have been seeing the National Instruments - Electronics Workbench Products continuously improve over the last 3+ years.

Again, I invite you to call me to address any additional concerns that you may have.

Regards,

Patrick Noonan
Business Development Manager
National Instruments - Electronics Workbench Group
patrick.noonan@ni.com

[Euler's_Identity]

Quote: "I have
researched this issue and I do believe the application engineers have
attempted to get back to you with several work arounds that have seemed
to correct the issue in version 10.0.1 and are waiting on a response
from you to see if you have tried their suggestions."

1. To date, as I understand it, there has been only one engineer working on this problem. If there is more than one, then please get me the others' contact info.

2. The last circuit "fix" I was sent did not work and I responded August 26, 2007:

-------------- begin paste -----------
Tien Pham,

I just got a chance to try out the latest version of the circuit you've sent
which you were troubleshooting for me.

First, MultiSim couldn't find my multiplexers, as it seems that there you're
pulling them from a directory that doesn't exist here.  (I'm just giving
you a complete run down on what happened.)  Therefore, for each multiplexer that
wasn't found, a pop-up window came up prompting for the file, where I loaded
the multiplexers from my directory, one by one.  Next, I zoomed in and clicked the
multimeter, as a voltmeter, to bring it up.  Then I zoomed out so as to see most
of the indicators and all the switches.  Finally, I clicked the on/off switch to
begin the simulation and ended up where all this began weeks ago: it wants to load
a circuit before it can simulate.

Therefore, we've accomplished zero with respect to this circuit.

Please explain to me what "creating a defect" means.  Also, what do you
and/or MultiSim intend to do concerning this (it looks like) multimeter bug?  When
might I expect a patch/solution for this?  

-------------- end paste -------------

From there I responded (on August 27, 2007) to the latest email, as shown below, where my response appears first: 


-------------- begin paste ----------- 

Tien Pham,

Ok. Thank you for the update. 

,[my name deleted]

-----Original Message-----
>From: support@ni.com
>Sent: Aug 27, 2007 4:59 PM
>To: [email address deleted]
>Subject: Re: (Reference#[deleted]) How do I simulate this circuit?
>
>Note:  Your reference number is included in the subject field of this
>message.  It is very important not to remove or modify this reference
>number, or your message may be returned to you.
>
>
>Hi [name deleted],
>
>Your design uses hierarchical blocks so you are linking files from
>different location on your main design.  When I am troubleshooting your
>file, I saved your circuits to a different path and when I sent the main
>file back to you, the link is not the same as your original file, I should
>have point the path back to your original location.
>
>The problem with your design is during the netlist load, this is where
>Multisim convert the schematic to a netlist for the simulation engine.
>When we looked where it was failing, it was pointing to the probes.   I
>went ahead and replaced all the “probes” in your design with and the “red
>Probes” instead and the circuit ran.    I can’t say for sure this is the
>real problem because your circuit is intermittent on my machine, it will
>work sometime and then it will fail with that load error.   I not confident
>the probe is the real problem and I think the problem is deeper than a
>component, I am still working on your circuit.
>
>
>
>Regards
>
>Tien Pham
>Applications Engineer
>National Instruments
>http://www.ni.com/support

-------------- end paste ---------------

Hence, I'm waiting on you. The ball's in your court, not mine.

However, just to make sure I'm not missing something, I will retrieve the latest circuit "fix," try it again, and then post the results here.
 

[Euler's_Identity]

Ok, with respect to the circuit "fix" I was sent on August 22, 2007, named "board_tester_1.ms10," I just loaded it, and I got this in response to clicking the on/off switch:

A window, "Simulation Error Log/Audit Trail," popped up which read:

--Warning:
--Simulation was not intialized properly. Please restart.

- Instrument operation performed  [2007, September 10, Monday, 17:16:52]
----+ Instrument Analysis: Transient Analysis
--- - Output from instrument analysis
------ Simulation parameter "reset options" can't be set until
------ a circuit has been loaded.
------ Simulation parameter "reset options" can't be set until
------ a circuit has been loaded.

So then I closed this window and tried again.

This time it seemed to simulate, as no window popped up and the simulation time showed and was advancing.  I was shocked.  So I clicked the multimeter and brought it up. I got a display of around 11mV or so, and this was correct.  Next, I chose to keep the mux bank address 0, set up pin address 1, and then tried to load the pin address.  It didn't load to the mux bank.  This means that, once again, the circuit returned is not the circuit sent, for the circuit works fine, at least that part did. 

(I've had so many problems with Multisim that I generally, as a design gets larger, save it under new names at various stages of operation.  That way, when Multisim burps, I can go back to when the circuit worked and then work from there.  That's how I know that that part of the circuit worked.  It takes up HD space, and you ought to see some of the filename chains I have, but at least I can continue to work to some extent.)

Working with this program and tech support is so frustrating. [sigh]

   

[Euler's_Identity]

Now the program just crashed.

"You chose to end the nonresponsive program, NI Circuit Design Suite 10.0."

I've decided it's high time I had others seeing this thing, and, as I've now cleared it for upload, I'm uploading the circuit to the forum.

This is the original circuit sent in to Multisim's "ask an engineer."  It consists of the main circuit and two hierarchical blocks. The hierarchical blocks are used to simulate the 1:16  and 1:2 multiplexers.

If anyone out there can figure out how to make this work and can upload an operational circuit that is also my circuit (to the extent that it is supposed to function at its present state, including indicators, and, at least, the entirely wired mux's of the mux's), I would very much appreciate it.