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Coinciding with the acquisition of VIA Development, Nate joined Autodesk in March of 2003 after a decade stint as an entrepreneur following a two-decade stint as a controls engineer and software applications developer at Owens-Corning. Nate is now the lead product architect for AutoCAD Electrical. He loves this stuff.
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Fear Not
April 22, 2006 08:10 PMby Nate HoltIf AutoCAD Electrical has the data but it's not output in the format that you'd like, don't be afraid to tinker. You can take an existing report and modify it with a "user post" or you can write the data out to a file and post-process it. You can even create your own custom reports by direct queries on your project's scratch database file.
Here is an example that surfaced recently. A user wanted to display a table listing relay tags grouped by assigned part number. Each relay tag entry needed to occupy a row of a table with the table's columns marked with the relay's valid N.O. and N.C. contact pin pairs. If a contact for the relay is present somewhere in the project, that cell in the table is filled in with the sheet and reference location of that contact.
This simple lisp utility, here, gives a good start in that direction. It just does a direct query on the active project's scratch database file, pulls in the data, formats it, and outputs to a comma-delimited text file. This can be displayed in Excel or inserted as a table on to a drawing.
Again, don't be afraid to play with this stuff, modify it to suit your needs. It can be fun!
UPDATE: this example Lisp utility uses some SQL-friendly calls that are supported only in the ACE2007 "API". If someone wants this to run in ACE2006 or prior, let me know.
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How much "lighter" is an east-bound 747?
April 20, 2006 04:58 AMby Nate HoltMy last long trip... center seat, coach, with every seat covered. If I want to open my PC's screen enough to see it clearly, I have to move it so close that I can barely type. If I want to push the PC out to where I can more comfortably type, I have to close the screen way down so it can fit between the tray table and my front neighbor's max reclined seat. Choice is a) see screen but can't type, b) type but can't see screen. Was not a happy time.
Mind wanders, trying to find something to latch on to for awhile to somehow speed up the passage of time. Need sudoku.
Okay, try to think about this... how much lighter is a 747 flying east than flying west? Is there a difference and might it be measurable? Gather known facts. Earth is about 4000 miles in radius which works out to about 25000 miles around at the equator. It rotates in 24 hours, so the rotational speed at the equator has to be around 1000 miles per hour in the eastern direction (sun appears to rise in the east since the earth is rotating in that direction). A fully loaded 747-400ER has a max take-off weight of 910,000 pounds (make it a million). Put cruising speed at around 600 mph.
So, two identical 747's, fully loaded, both at cruising speed, pass each other over Singapore (on the equator). The first 747 is flying due east, the other flying due west. How much "lighter" is the east-bound 747 than its identical twin flying west?
With the earth's 1000 mph rotational speed at the equator added in, the east-bound 747 is "spinning" around the globe at 1600 mph to the east. The west-bound 747 is working against the 1000 mph eastward spin of the earth, so the net "spinning" speed for it is only 400 mph.
Could a 1200 mph rotational speed difference be enough to register a measurable "weight" difference?
Donno. Think about the extreme case. How fast would a 747 have to be spinning around the globe in order to have its "weight" drop to zero? It happens with anything put into orbit. From grade school days, us kids learned that astronauts would orbit the earth every 90 minutes or so. In low earth orbit, it's probably a bit more than 25000 miles to get around the globe. Doing it in 90 minutes works out to about 17000 mph. So if we could get our 747 up to 17000 mph, we'd either break apart or we'd experience a 100% reduction in "weight".
What about the 1600 mph versus 400 mph for the passing 747s along the equator? The calculator here gives the difference in centripetal acceleration for the different speeds around the 4000 mile radius earth. According to the calculator, the 1600 mph 747 would experience a 0.0081G negative acceleration and the 400 mph 747 a 0.0005G negative acceleration. Multiplying the difference by the million pound weight of the fully loaded aircraft yields a "weight" difference of 7600 pounds.
Seems like a lot. Could this be right?
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ACE2006/2007 project file compatibility with ACE2004/2005
April 19, 2006 01:44 PMby Nate HoltEarlier versions of AutoCAD Electrical (pre-2006) expect to find full drawing paths defined in a project's ".wdp" ascii text file. But with AutoCAD Electrical 2006/2007, the project file defaults to using relative paths for the drawing files... "relative", that is, to the location of the project file itself. This newer approach is much cleaner and really helps with portability. But it causes problems when a ACE2006/2007 relative path-based project file is called up with an earlier version of AutoCAD Electrical. The earlier version expects to find full paths defined... it isn't set up to handle relative paths.
So, let's say you are running the latest and greatest but you are interacting with a customer who hasn't yet moved past ACE2004/2005? One solution is to maintain two versions of the project ".wdp" file, yours and the 2004/2005 version that has the full paths defined.
An alternate solution might be to create a utility to rewrite a 2006/2007 project wdp file so that it includes full drawing paths instead of relative paths. This would make it compatible with 2004/2005 and still allow it to work in 2006/2007 (which uses relative paths but can read and process full paths as well).
Here is a sample Lisp (revised) utility created with calls to the ACE2004/2005 "API". It should run in either version of AutoCAD Electrical 2004 or 2005. I ran some tests and it seems to work okay with various scenarios: 1) dwgs in same folder as wdp or in subfolder, 2) dwgs in folder closer to the root, 3) dwgs on another drive. It's in full source format so you can re-edit it to suit.
If you want to give it a try (at your own risk!):
1. Download and APPLOAD into ACE2004/2005
2. Type WDP_2005_CONVERT [enter] at command line
3. Browse to and select a 2006/2007 wdp file to process
The result should be the wdp re-written with full paths and overwriting the original. If you want it to rewrite to a different name, open the Lisp file with an ascii text editor or the built-in Visual Lisp editor and adjust the code.
UPDATE: Glenn Buttke reports that the utility chokes on file names with UNC prefixes. Download revised file and give the new version a shot.
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TMI
April 18, 2006 02:17 PMby Nate HoltIn an earlier era, the upper bookcase shelf housed a couple fistfuls of well-worn vendor catalogs. It was an easy reach across the tilt-board drafting table to grab the information I needed. Cutler-Hammer for relays, motor starters, and pushbutton operators, Hoffman for enclosures, Reliance and Allen-Bradley for PLC I/O, and some GE and Square-D thrown into the mix.
Standardizing on what we used in designs was important. One simple reason was shelf space. The theory was that the plant store room needed to stock at least one of every item used in critical control and process systems - failure at 11pm Saturday night could not wait for some electrical parts supply house to open its doors Monday morning.
Sometimes the clerk couldn't find a part and would let me inside the store-room's sacred caged walls. Long, dark aisles formed by hulking metal shelves filled with wonderful, mysterious things. Some fresh and clean and others covered with a think coating of dust. The latter condition might be because the item in service never broke. But, just as likely, it could be that the dusty item languishing on the shelf was a replacement part for a one-of-a-kind item specified in some long-forgotten control system project.
I'm tempted to knock out the next quickie project and specify that fancy, cool new illuminated selector switch with tingly-tactile feedback instead of the plant store-room standard model. It sure would make my new control panel stand out from all the rest. But it runs the risk of creating a new store-room dust magnet. There's an extra cost involved in all this too (accountants figure this stuff out).
AutoCAD Electrical 2007 ships with a significant increase in its default catalog lookup content. There's a lot more, maybe more than you want to sort through or have the program have to process. Or maybe you don't even want to see certain content so that there's no temptation to specify components outside of the company's standards.
The attached example Lisp utility might be useful for selectively hiding certain categories of catalog content from being displayed. It lets you pick a component family type and then browse through the content and highlight sections that you want removed. What you chose to remove is not deleted but is moved to a separate table called "_NOT_USED" in the database file. You can rerun the utility to restore it fully or partially later on, as you see fit.
To try this example USE AT YOUR OWN RISK ( ! ) utility:
Download file
1. Download the above file and unzip files ace_catmod.lsp and ace_catmod.dcl into your "c:\program files\autodesk\acade 2007\support\" folder (or any folder in the ACAD path)
2. Back up your default_cat.mdb catalog lookup database file (important!)
3. Start AcadE 2007 and APPLOAD the ace_catmod.lsp file
4. Type ACE_CAT_MANAGER [enter] at the AutoCAD command line. Follow prompts.
UPDATE: this Lisp file and support dialog definition "dcl" file are in full-source format. Feel free to enhance as you see fit! Edit with any ascii text editor or use the built-in AutoCAD Visual Lisp editor (type VLIDE at AutoCAD command line).
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Multiple ASSYCODE trick
April 8, 2006 07:25 PMby Nate HoltA question about multiple ASSYCODE assignments to a single part number assignment came up recently in an AutoCAD Electrical discussion group posting...
Let's say you're propulating the ACE catalog lookup database with some special DC variable speed drive part numbers. For each drive part number you want to have two options: a standard dynamic braking resistor kit and a standard remote lock-out switch kit. In order to accomodate all possible combinations, you don't really want to create four catalog lookup entries for each DC drive part number (bare drive, drive+DBR, drive+LO, drive+DBR+LO).
One solution is to use the "Multiple Catalog" feature, browse and pick the extra part numbers. But there is an alternate way to do this...
1. Create the bare, drive-only catalog entries for all of the DC drives.
2. Create two more catalog entries (as ASSYLIST entries called "DBR" and "LO-KIT") for the dynamic braking resistor kit and the remote lock-out kit.
Now, in operation, you pick the bare drive from the normal catalog lookup listing. Then, in the ASSYCODE edit box, you manually enter one or both of the assembly options, DBR or LO-KIT or both. If both, delimit with a semicolon like this:
DBR;LO-KIT
ACE will report the main "bare" drive part number information plus the part(s) for the dynamic braking resistor kit plus the part(s) for the remote lock-out,
But let's say you really need 3 of the lock-out kits for this drive (along with the DB resistor). Enter this into the ASSYCODE edit box:
DBR;3,LO-KIT
The "3," preceeding the assembly code value will triple the quantities of that assembly list.
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Current Connection blog
April 7, 2006 06:04 AMby Nate HoltCheck out Robert Stein's blog. It's called Current Connection and he states that it is "a site dedicated to sharing what I know about AutoCAD Electrical". Very cool...
http://www.robstein.blogs.com/
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Trick with Type 0 Pin list
April 7, 2006 05:41 AMby Nate HoltHere is an obscure PINLIST option for "convertible" contact pin annotation.
Let's say that a certain relay has convertible contacts stamped with pin designations "A" and "B" for the contact in its "Normally Open" orientation. But, if you flip the convertible contact over so that it operates as a "Normally Closed" contact, the contact's pin designations that are now visible to you are stamped "C" and "D". How can you set up your type "0" pin list assignment to handle this situation - different pin assignments visible depending upon the physical orientation of the contact in the relay body?
Encode the relay's coil symbol PINLIST like this (for four convertible contacts):
0,1A,1B,1C,1D;0,2A,2B,2C,2D;0,3A,3B,3C,3D;0,4A,4B,4C,4D
where each type "0" contact (convertible contact flag) is followed by four pin assignments instead of the normal two. The first two assignments will default to the contact when it is inserted as a normally open contact. The last two assignments are applied if the contact is flipped to normally closed.
Try it... it seems to work. Insert a relay coil and manually enter the above PINLIST into the "NO/NC Setup" sub-dialog. Now pop in a N.O. contact and associate it to the parent coil. The pin assignments will be "1A" and "1B". Pick on the "Toggle NO/NC" command and flip this contact to a N.C. contact. The pins assignments will automatically update to "1C" and "1D".
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The Sun rarely sets on AutoCAD Electrical development
April 6, 2006 10:35 PMby Nate HoltIf it does manage to set, it pops back up again pretty quickly. Conference calls and web-based meetings with development team members spread out across the globe have become an almost daily (and often nightly) occurrence. We have to keep track of time differences, what day it is, and when to greet with "Good (morning/afternoon/evening/all of the above)" from here in Novi, Michigan versus other development locations like Singapore which nearly straddle the earth's equator on the opposite side of the globe.
We've now have had a couple flips between Daylight Savings Time and back again. Just this last weekend was the less-desirable flip... we (in the US) lost an hour of sleep Saturday night.
The previous time this happened, I asked my Singapore counterparts if this Daylight Savings Time concept made any sense on that side of the world. It didn't really... with Singapore located on the equator, DST seemed to be an unknown like windshield ice scrapers, antifreeze, long johns, and chewing gum.
Question: Why? Are days and nights on the earth's equator always the same length? Does the sun rise and sun set at the same time, every day, year round on the equator? Hmm... visualizing the spinning globe with an appropriately placed flashlight, it seems that the equator would always be illuminated for exactly half a rotation, no matter how the globe was tilted to mimic the four seasons. Better check this out for sure.
Answer: Sure enough. On the equator, day lengths are consist year-round. Sun rise and sun set tables for both Singapore and Novi for 2006 (http://aa.usno.navy.mil/data/docs/RS_OneYear.html) show the huge difference and why DST makes sense only for cities significantly removed from the equator. Here's the data for the first day of each season:
Singapore (year 2006)
Date Sunrise Sunset Daylength
Mar 21 0604 1811 = 12:07
Jun 21 0558 1805 = 12:07
Sep 21 0550 1756 = 12:06
Dec 21 0554 1802 = 12:08
Novi, Michigan (year 2006)
Date Sunrise Sunset Daylength
Mar 21 0636 1847 = 12:11
Jun 21 0457 2015 = 15:18
Sep 21 0620 1833 = 12:13
Dec 21 0800 1704 = 9:04
Wow! Novi - 6 hour swing in day length throughout the year, Singapore, 2 minute swing.
But the Singapore day length number column uncovers a new mystery. How can the average day length throughout the year 2006 always be seven minutes greater than 12 hours. Shouldn't it average out to exactly 12 hours of day and 12 hours of night? Hmm... better do some more thinking about this.
Clue - the table data definition for sunrise is the top of the disk just peeking above the horizon. That's fine. But the definition for sunset is the top of the disk just disappearing below the horizon. Hmm... night-time is getting cheated out of one width of the sun's disk. To be fair, sunset should be the bottom of the disk just touching the horizon. So, does this injustice account for the mystery 7 minutes in Singapore? Let's figure it out. The sun is about 0.8 million miles across and is 93 million miles away. Enter this AutoLisp expression: (* (/ 180.0 pi) (atan (/ 0.8 93.0))) [Enter]*. This works out to the sun's apparent disk width being one half degree of arc. This is about the same width as holding a quarter (US $0.25 coin) about 10 feet away from your eye (if you try this, use the moon, it's safer - the moon is the same apparent size as the sun - convenient for total solar eclipses).
So, how long does the sun take to fully set in Singapore, from the time a 1/2 degree width disk touches the horizon until the time the last bit disappears. Let's figure it out. 24 hours to go through 360 degrees works out to about two minutes to rotate through the 1/2 degree needed to hide the setting sun. Hmm... still have 5 minutes to account for.
Clue #2 - Okay, between sunrise in Singapore and sunset about 12 hours later, the earth has moved along its orbit, gently turning a corner toward the sun. The earth's rotation direction is the same direction as its rotation around the sun (I think), counter-clockwise if viewed looking down from above the North pole. So, after 12 hours, wouldn't the earth have to rotate just a tiny bit more to make up for this gradual 12 hour turn? If so, let's figure it out. 365 days to go through 360 degrees, so about one degree per full day/night or a half degree during a 12 hour Singapore day. Another two minutes accounted for: now four of the mystery 7 minutes.
Clue #3 - Three mystery minutes of excessive daytime remain. The only thing I can think of at this point is that the earth's atmosphere might bend the light a bit when viewing along the horizon. It would have to make the very top of the sun's disk still visible (stretching it) even when the sun had actually fully sunk below the horizon at sunset (and the top of the sun appear a bit prematurely at sunrise). Anybody?
* Needed to get something AutoCAD-related into this posting!
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About the
April 4, 2006 09:05 PMby Nate HoltNow for the best part. The 'Blogger' who has graciously stepped up to own this Blog is none other than the man that I've long deemed as the father of electrical CAD, Nate Holt.
Nate is now the lead architect for AutoCAD Electrical and has an incredibly interesting background in ECAD that h's far too modest to tell you about so I will.
Nate spent 23 years in industry, first as a plant electrical engineer and then as a controls engineer designing and installing chemical batching systems. Along the way, Nate had the vision to customize his employer's five ComputerVision seats to automate many of the mundane tasks involved in electrical design (this was back in the days when a seat of CAD started at $100K!). This started him thinking about the potential of affordable ECAD.
After two-plus decades working for someone else, Nate turned entrepreneurial to develop and launch his own AutoCAD-based ECAD package. Since he had just spent the previous twenty-plus years of his life running conduit, landing wires, programming PLC's, starting up machines, and living in front of a computer monitor, he (and his one employee, Pat Murnen) really understood the needs of his target market, the controls engineer.
After five years of rapid growth in the market and really putting the crunch on the competitive ECAD products, Nate's company was acquired by VIA Development Corporation. This is where I came to know Nate - when I was VP of VIA.
The rest is history. Autodesk acquired the product from VIA Development and launched the AutoCAD Electrical.
As you know, AutoCAD Electrical is now available in 9 languages and its use is rapidly spreading all over the world.
So, Nate will do almost all of the blogging on this site but every now and then, I'll jump in and steal the thunder for something that someone else did. Hey, that's the job of the manager right?
Remember to bookmark this page, visit often, and enjoy!
Scott Reese
AutoCAD Product Line Manager - Manufacturing
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Father of AutoCAD Electrical CAD turns Blogger
April 4, 2006 09:03 PMby Nate HoltWelcome to the newest addition to the Autodesk manufacturing-focused Blogs. The "Controlling the Machine" Blog will focus on automation, controls, and electrical engineering in general.
We will also provide tips and tricks as well as some interesting "unknowns" about the AutoCAD Electrical product.