07-18-2012 10:41 PM
I've looked for some documentation explaining exactly how the pin and gate swap functionality works but I have not been successful.
I am trying to get pin and gate swapping working correctly on some digital logic components that I have created (side question - why no modern 74 series logic components like LVC?) as well as RPACKS and some connectors.
Is it a requirement to create a multi-section symbol to enable gate swapping? I can't seem to get it to work unless the symbol has multiple sections. It doesn't work by default for the RPACKs included in Multisim. If it's possible to do gate swapping by putting the pins of each gate in their own gate swap group I would really like to understand what I'm doing wrong.
In the Component Properties 'Footprint' tab you can define the 'Pin swap group' and 'Gate swap group' settings. I have not seen any documentation explaining this and frankly, I'm quite confused by it when using existing 74 series parts as examples. The single section symbols don't have any pin swap or gate swap groups defined and the multisection symbols have only one gate swap group and then put all inputs in one pin swap group and all outputs in another pin swap group.
I would really appreciate it if someone could point me to documentation that explains how to do this. The help files are quite poor in my opinion - they seem to only be able to point out the obvious. The 'Getting Started,' 'Fundamentals,' etc. type guides don't mention this stuff at all. The 'User Guide/Manual' (both of which appear to be outdated?) do not explain this and frankly don't have very much information about pin and gate swapping at all.
I'm hoping I'm just missing something obvious.
On a related note - I'm having some trouble working with some of these multisection components. When I want to change the footprint or update the component after making a change to the component in the database I can't seem to find a quick way to do this. It seems that I always have to go through a drawn out process of 'Replacing' each individual symbol section. Is there a faster way to do this?
07-19-2012 05:37 AM
I'll check but most of our default component gate swapping is enabled on multisection parts only. However I am not sure if this is a requirement or not (we'll check and get back to you)...
> side question - why no modern 74 series logic components like LVC?) as well as RPACKS and some connectors.
Please let me know which specific connectors you'd like to see. As for RPACKS and LVC, can you send me of the manufacturers/families that you are interested in?
> The help files are quite poor in my opinion
The help is setup to be very specific to a function and feature, but I agree it is not very intuitive for a use case to answer 'how do I best do this...' For this type of thing we've created some whitepapers and several series of 'best practices' guides for certain functions. We're trying to do more of these as well... I'll check with the Apps Engineers to see what is available but I think if you do a search you'll be able to find stuff online.
> On a related note - I'm having some trouble working with some of these multisection components.
I think I've seen something basic guides on multisection part creation on this website, if not we can certainly create something for you. Also send me a private message and I can send you something that might help.
>On a related note - I'm having some trouble working with some of these multisection components. When I want to change the footprint or
> update the component after making a change to the component in the database I can't seem to find a quick way to do this. It seems that I
> always have to go through a drawn out process of 'Replacing' each individual symbol section. Is there a faster way to do this?
If you go to Tools -> Rename/renumber components... this alllows you to do section swapping on multisection components better than replace. However, there is actually an existing feature request that we're working on to improve schematic level "gate" or symbol swapping.
07-19-2012 12:42 PM
I'm working with some SAMTEC connectors. I don't expect you guys to have these built by default in the library - they are somewhat custom. But just so you can consider it, we are using the TFM and T2M family of connectors and I'm adding them as additional footprints for the standard dual row headers. I'm having some trouble with the footprint for the TFM screw-down option since it is a very odd footprint, but I'm going to start a seperate thread discussion for that since I really just need to understand how to manipulate Ultiboard to get the desired result and it's really a different discussion.
As for RPACKs, I'm a little confused about how Multisim currently supports these. The Value tab in the properties dialog only lets you set the resistance. Why isn't this more like the resistor value tab? Since the Value tab is modified like a virtual component it's disappointing that it doesn't offer more capability like the other virtual passives. In my limited experience I've seen the isolated-4 resistor pack used the most, but like I said, that is limited experience. It would be nice if some surface mount footprints were added to the master database for RPACKs in the future. 4x0402, 4x0603, and 4x0805, concave and convex, seem like pretty common footprints as best I can tell.
Virtual components work great in a purely physical design because you can easily change the footprint in the 'Value' property tab. With the provided RPACKs and LEDs you can't do that, so I had to create new components in the User/Corporate database. Of course, the LED can't be copied so I had to create it from scratch. But the RPACK could be copied even though it had a modified Value tab, implying it is a virtual component, if I understand correctly. Maybe these distinctions and limitations are well defined but I found it somewhat confusing that there were several common parts I had to either copy and modify or build from scratch.
Since I created those parts, we updated to the PowerPro version and though I'm not certain, I think I can change the footprint in the spreadsheet view. But in the standard version, I didn't see a way to change the footprint without replacing the component.
Also, it seems like changing the footprint does not behave quite like I would expect. If I have a database part which has multiple footprints mapped already, I would expect to be able to choose between those footprints already supported by the database part when I try to change the footprint using the Properties->Value tab or the spreadsheet view. If I need to change to a footprint that currently is not associated with the component in the database, I would expect to have to edit the database part, add the footprint, map the pins, re-save the component, then update the component in the schematic.
Is my thought process making too many assumptions here? I understand that I am one person creating one design in one specific way. So I'm sure I'm missing some usage cases or intended uses of the tool, especially since I haven't taken any training for this software and have tried to teach myself how to use it over the last 9 months. And I have noticed that even for virtual resistors and capacitors, the footprint selection dialog is the same - a selection from the database and setting up a new pin mapping.
As for 74 series parts, seeing the LVC family would be very nice. This is 3.3V-2.5V and seems like the next logical step for lower voltage support. It would also be nice to see some surface mount footprints with the 74 series parts. This isn't a big deal though - it didn't take me long to create the parts I needed by copying and editing from the Master database. And since I'm not using the simulation models, that made it even easier. Since I haven't looked into the models at all, I don't know if that would have taken longer to convert to the LVC family.
I've probably rambled enough for now.
07-26-2012 09:17 AM
Some components such as LEDs, RPACK have custom dialogs and unfortunately, they don't have the button allowing you to change the footprint. The only way to change the footprint for these parts is to do it on the Spreadsheet View. I've created a feature request this and hopefully, in the future any part with custom dialog will have the Edit Footprint button.
If you assigned multiple footprints to a part, the best way to change the footprint is to double click on that part and select the "replace" button. This should bring you back to the Select a Component where you can select a different footprint assigned to the component.
08-14-2012 08:37 AM
It would also be nice to add as a feature request that RPACKs be handled like other passives. They have the ability to adjust their value on the value tab but you can't manage them like other passives with the 'RLC Components' tab in the database manager. This means that you have to create copies for every resistor value in the database and then place the specific value component in order to get the BOM to work out correctly. Obviously you can edit the BOM, but the whole idea is to avoid that since hand edits are prone to error.
One other thing, the 'RCL Components' tab is extremely useful for quickly managing the part details for passives. However, the footprint selection dropdown only selects footprints from the Master Database. This limits the usefulness of this interface. If I have 20 or 30 parts in the design and I need to switch them to a part that is unusual or unique in some way which requires a footprint modificatoin I have to change each individual part instance instead of being able to quickly make the change in the 'RLC Components' tab.