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Posts from — February 2012

My Favorite Pen Types

What works for me for normal writing:

  1. Micro gel pen in the 0.4 mm range, such as the Uni-ball Signo DX 0.38mm and Pilot G-Tec-C/Hi-Tec-C 0.4mm (but I’m not a Zebra Sarasa 0.4mm fan).  These pens smoothly put a vivid, colorful fine line onto my paper.
  2. Hybrid pens such as the Zebra Surari (my favorite), Uni-ball Jetstream, and Pental Energel in 0.5 mm or 0.7 mm.
  3. Rollerballs such as the Pilot/Mont Blanc G-Blanc, Uni-ball Vision, and Pilot Precise V5.
  4. Fountain pens.  I have a Kaweco Sport, a Pilot Petit, and a Pilot Plumix.  They’re nice, but just don’t get me excited.  I like easy care and portability; fountain pens aren’t great at either, and they’re pricey.  I like the look of gel ink better than fountain pen ink (at least the inks I’ve seen).
  5. Ballpoint pens.  Most are just kind of blah.
  6. Felt tip pens such as the Sharpie Pen, Sakura Pigma Micron, and Uni-ball PiN.  I just don’t like they way they write, and I am always concerned I’m going to squish the point.

I try to periodically re-evaluate; I’ve been trying to use my fountain pens a bit more, eventually I’ll give the Sharpies another chance, etc.

Fountain pens with broad nibs are a lot of fun when I’m in a playful mode, as are glittery gel pens, metallic gel pens, brush pens, and so on.  However, for normal use, I like thin to moderate lines, solid coloring (no skipping), easy care, and inexpensive (so I can put it in my pocket).


February 29, 2012   3 Comments

Do Product Names Matter To Engineers?

Do product names matter to technical folks?  I think they can be important in retail marketing (e.g. iPhone, Word, Windows), but to engineers?

A lot of companies still use numeric product names; for example, a Kollmorgen AKM21 servo motor, the ST STM32 MCU, etc.  Other companies prefer using words; for example, Copley Controls has the Accelnet, Xenus, and others.

However, I’ve noticed a trend towards using easily pronounceable words for product lines.   TI is a great example; everything used to have a number (TMS320C6201, TMS320F2401, etc), but now TI has OMAPs, Sitaras, Delfinos, Piccolos, Wolverines, and probably a few I’ve missed.   Of course, Intel changed over from “x86” to Pentium, but I believe the original reason was because “86” couldn’t be trademarked but Pentium could.

I don’t care either way; I guess it’s easier to say “Accelnet” instead of ADP-055-18, but it also conveys less information.

February 28, 2012   No Comments

Schneider Altivar ATV31H037M2 VFD

I’ve been playing around with my Schneider (formerly Telemecanique) ATV31H037M2 0.5 HP VFD (variable frequency drive).  I’ve put up some notes here.  Here are my thoughts:

  • If I ever need a VFD at work, I’ll consider Schneider.  Based on a quick look, pricing seemed in-line with comparable VFDs.
  • I think the -A version (with speed control on the front panel) is worth the extra ~$30 since it makes playing around machine setup so make easier.  You can jog the standard version using I/O and switches or via software and Modbus/CANOpen.
  • I really like having CANOpen as a standard interface (Modbus is also standard).  However, the CANOpen setup isn’t ideal, since you’ll have to make a custom cable or use a breakout board.
  • There are a lot of settings; the drive appears to be very flexible.
  • The manuals are very long and thorough.
  • However, the manuals don’t provide much guidance on how to tie all the settings together (so I’m not sure when to use the more advanced settings and how to use the various settings together).
  • Good cable and wire flow.
  • The AC power input and drive connectors do not have permanent labels; but so far the sticky labels are still hanging on.
  • The buttons are cheesy dome switches, which will probably wear out quickly if they are used heavily.
  • The controller’s user interface sucks; to be fair, I’m pretty sure it’s similar to most VFD’s.  If you’re doing a lot of setup, it’s probably worth getting Schneider’s cable and setup software.
  • The newer ATV32 drives are pretty different; for example, the dome switches are gone, and you can get a CANOpen communication card with dual RJ45 connectors.

February 23, 2012   No Comments

Book Review: Cascading Logic

Cascading Logic: A Machine Control Methodology for Programmable Logic Controllers by Gary Kirckof, P.E., published by the ISA.
My rating: 4.0 out of 5.0
Summary: A good but imperfect book

Cascading Logic is a unique book: it is the only intermediate level PLC programming book that I found (I have not found any advanced PLC books).  Sometime I should discuss why I think there are so few intermediate and advanced books (basically, PLC market size and fragmentation), but here is what I expect for each level:

  • Beginner book: an overview of PLC programming, and some discussion on how to do tasks.
  • Intermediate book:  how to put a complete PLC program together and why you should do things a certain way (best practices).
  • Advanced book: how to write the best PLC program, tips and tricks, covers advanced applications such as motion control, interfacing to advanced sensors (such as machine vision), analog I/O, and using advanced PLC instructions.

At $89 for a 206-page book, Cascading Logic is not a good value (unless you can find it used for a decent price), but it is still very much worth reading if you program PLCs professionally.

So what do I think?

  • It’s the only PLC book I found which covers how you should program a PLC (the best practices of PLC programming).
  • It’s not for beginners (in PLC programming or automation); a beginner would have a hard time following the examples.
  • The book is well written overall, but the style is terse.
  • The book builds on concepts to show a pretty complete program that covers most areas needed for a real machine (including operation, startup, errors, maintenance) and how to write code that can  be easily understood and updated.
  • The examples are too narrowly focused on automotive assembly machines; automation is a very broad field.  My PLC usage has nothing in common with the author’s examples.
  • The book only uses basic PLC instructions that all PLC have.  Overall, this is a plus, since it makes the book applicable to all PLCs, and thus a good starting point for any PLC programmer.
  • The book only covers basic systems with pneumatics, binary sensors,  and clutched motors.

I’m very glad I bought the book.  I have a lot of thoughts on PLC and PC automation programming, but I need to finish a series or two first…

February 21, 2012   1 Comment

My Choice For Writing Technical Manuals

I’ve been researching software that could be used for writing technical manuals.  My requirements include:

  • Doesn’t go crazy when I change formatting around (unlike MS Word)
  • Low cost or no cost, unless the benefits are overwhelming.
  • Reasonably good control over layout, but I don’t need super-precise control.
  • Easy to create Table Of Contents and cross-linked references.
  • Handles graphics, tables, and lists with aplomb.
  • Good, well written information (help, books,  blogs) available so I can quickly learn how to do what I want to do.
  • Easy to update text and improve text.
  • Easy to change formatting (for example, by using styles and updating the styles).
  • Good performance with long documents.  A lot of writers create one document per chapter, but I want to keep the whole manual in one document so it’s easier to create references, TOC, and such.

The basic types of programs available are:

  • Word processors, such as Word and Writer, that focus on the content and not on precise formatting.
  • DTP (desk top publishing) software such as Scribus, Adobe InDesign, and Quark Express that are really optimized for page layout; they typically don’t handle editing well, and often choke on long documents.
    • I took a long look at the open source Scribus program, but decided that this category wasn’t a good fit.  I expect the manual to be updated frequently, while precise layout simply isn’t needed.
  • Very structured software such as Framemaker and the TeX variants. These are more structured than I need, plus I want something more graphical than TeX.

My choice is LibreOffice Writer because:

  • Writer has better DTP capabilities than MS Word.  For example, it has styles for pages, characters, and frames, not just paragraphs.   A typography extension is available as are a couple of free, high quality fonts.
  • Writer is roughly comparable to Framemaker in capabilities (see here and here).
  • Writer is free, which is nice.
  • Writer doesn’t seem to go crazy when re-formatting; when I import my lengthy Word document and start changing styles, it does what I expect, unlike Word.  Performance on a 200 page document is acceptable.
  • There is some very good documentation available, including:

I plan to write an update when the manual is finished.

February 16, 2012   2 Comments

Microsoft Word 2010 for Technical Manuals

I’m in the process of slowly updating a technical manual; it’s currently in Microsoft Word, and was created by merging several earlier manuals.  The manual is over 200 pages long, and contains many photos, illustrations, and tables.

And I’m ready to dump Word.  I’ve used Word before, starting with Word 95, to write tech manuals but I’ve taken a lengthy break from tech writing.

I’m not a fan of the ribbon interface.  It’s like Apple stuff — it works great if you think as the designers do, but doesn’t work well if you think differently.  All those big icons and such make the supposedly more common stuff easier to find, but it makes the other features harder to find.  The ribbon interface makes it harder to explore and find out all of a program’s capabilities compared to browsing through menus.

I don’t like the current Word Q&A help system, either.  OK, I may be an old curmudgeon, since I haven’t like Word’s help since Word 95 — I think that was the last version that really tried to explain the basic concepts such as styles.

In my experience, Word can work pretty well if you start from scratch and lay out everything first, such as your styles.  If you have a Word document with inconsistent styles, lots of manual formatting, etc, and you’re trying to substantially modify its structure and appearance, watch out.

My current document’s problems include styles automatically changing when I try to apply them (and then changing the formatting of all the text tagged with that style to something I don’t like), tables flying apart or flipping when I delete some text or an object, and such.  I’ve quickly grown tired of re-doing the same thing over and over, so Word is out for lengthy technical documents.

February 15, 2012   2 Comments

Updating Trac

I’ve been doing some updates on my Trac site; it really needs a lot of updating, but I’m concentrating on improving and adding to the motor section (which ties into the XY Table series…which I will get back to real soon now).

February 8, 2012   No Comments