Category — Products

I’ve come across a couple interesting devices recently.

• Icop VESA PC, the eBox 2300 and eBox 4300.  These PC’s mount to the VESA mounting holes on the back of most LCD displays.  The Icop models are actually affordable, unlike many mini PC’s. The 2300 is very cheap (starts at about $100), but not very powerful (200MHz or 300MHz CPU).  The newer 4300 is much more interesting, with a 500MHz Via CPU, and a reasonable price (about $250).  If you need a Panel PC, but don’t need a tough industrial case, these can make a great lower cost alternative – just get a regular monitor (<$200 for a pretty nice one) or touchscreen (~$650 for a 17" Planar touchscreen LCD), and mount the eBox 4300 on the back.  The 4300’s performance should be good enough for HMI use (assuming you’re not running Vista…)
  • The Icop PC’s are availabe in the US from WDL Systems.
  • Linux Devices has an eBox 4300 review.

• The Olympus Micro Four Thirds system could lead to some very interesting cameras – cameras that combine SLR performance, image quality, and interchangeable lenses with digicam size.  Check out the pictures at DPReview.  They won’t replace Digital SLR’s (heck, Leica is coming out with a "super-sized" D-SLR with 30×45mm sensor), but I’m very interested in one as a complement to my D-SLR for everyday picture taking (instead of a pocket digicam).

I’ve added a section on my wiki describing how to make a serial cable to connect to the Panasonic FP0 or FP Sigma Programming Port. Later I hope to update it with more pictures.

Tony

Let’s say you want to learnplay with real industrial automation equipment in your garage (or living room, if you’re single), not toys like the Lego Mindstorm. After all, learning is fun, and it’s cheaper than taking college classes (that’s what I tell my wife). Unless you’re rich, buying surplus is the way to go.

In the past, if you lived in the right area you could visit the local surplus store. Silicon Valley used to have a lot, but most of them disappeared during or after the dot-bomb bubble and subsequent crash. Still, there are a few places left, such as Triangle Machinery (the best place for mechanical stuff) and Excess Solutions. DeAnza College hosts the monthly Electronics Flea Market.

Now the overall situation is better because of on-line sites such as eBay (still the best overall), craigslist (worth checking, but probably best for test equipment), DoveBid (typically best for test equipment or large industrial equipment), and PlcCenter.

Mechanical items such as stages and motors are pretty easy to use. But when looking for equipment such as motion controllers or PLC’s, you need to consider:

1. What software does the equipment require? The best case is when the equipment comes with software or you can download the software from the manufacturer’s web site. Next best is when the necessary software is at least somewhat reasonably priced (so you can afford to buy it (e.g. some PLC software)). The worse case is copy protected software (Allen-Bradley, Cognex, and many others).
2. Does it come with documentation or can you download it?
3. Are the necessary accessories readily available? If it’s a rack, backplane, or snap-together system (many PLCs, Opto 22, Beckhoff, Wago, etc), you have to be able to get all the required pieces (backplane, power supply, CPU, I/O modules, etc). For a motion controller, are the break out boards and cables readily available?
4. What are the power requirements? Many servo drives are 3 phase 240V or 480V.
5. Is it readily available surplus? Important if you want to expand later.
6. Have you used it before? Familiarity obviously helps.

My recommended list:

• Galil motion controllers. Yeah, the two letter commands are stone age. But Galil controllers are readily available on eBay, you can download all the essential software and documentation, the connectors and breakout boards are readily available (but if you buy them new they might cost more than the controller cost on eBay!), and it’s easy to get started.
• Opto 22 PACs. I haven’t used them, but software for the SNAP controllers is free, and they’re often available on eBay.
• DVT smart cameras. Software for the older models is free, and they’re often available on eBay. I’ve heard that software for newer (after Cognex bought DVT) models is protected.

CANOpen is a mixed story. CANOpen availability is good (AMC DX15C08 Digiflex drives are readily available at great prices, other drives such as Copley Accelnet, Copley Stepnet, Baldor MintDrive, and Kollmorgen Servo Star are occasionally for sale, and I/O controller such as Wago 751 series are sometimes seen). However, you will need a CANOpen interface (I recommend Acacetus VCCM or Peak USB-CAN because they’re supported by CanFestival). Getting started with CANOpen is still a lot of work; starting from no knowledge, it takes much more effort than getting a Galil system up and running.

• Plenty of others, including many I haven’t heard of. Other possible examples include Logosol, Animatics SmartMotor (also stone age commands, but…), and JR Kerr’s PIC-Servo boards (quirky, but affordably priced new).

Not recommended:

• MEI motion controller without software – nice boards (the XMP looks really nice), and occasionally seen on eBay, but IIRC the software is $4900 for the older systems and $19,000 for the XMP.
• Cognex Insight smart cameras. Nice systems, often available on eBay – but every time you install the software you have to call Cognex to get a key for that particular PC.
• Most PLC’s, especially any you have not used, unless they come with programming software and the appropriate licensing (dongles, disks, etc). The “big name” vendors like Allen-Bradley tend to like nasty copy protection schemes – software keys that have to transferred via floppy disks are the worst, since they are so easily lost (and who has floppy drives anymore?) . At least hardware dongles are harder to lose.
• Anything you don’t know about or can’t find out about.

Some good sources for cables and breakout boards:

• L-Com
• Cables On Demand
• ASI

Sometimes it takes patience and multiple sources to put a working system together. I bought my Wago 751 series CANOpen controller from eBay, but I bought the I/O modules from PlcCenter (they were available at reasonables prices). I bought my Festo CPV-10 CANOpen control module from eBay about a year before I found the CPV-10 pneumatic manifold and valves available at a reasonable price.

Tony

I like to highlight unique products that fulfill real needs. At work, our equipment is used both domestically and internationally, so it’s good to be able to easily switch between 120V 60Hz and 240V 50Hz. We like to use unregulated linear power supplies to power the motors, since they have good response, and are inexpensive.

So I went looking for a unregulated linear power supply with a switch to select either 120V or 240V windings, and found only one company that makes them – Logosol. Logosol’s 250W and 600W power supplies have an input voltage selector switch; both models also have separate motor and I/O power supplies, and the 600W model has an E-STOP input.

It’s possible to add a switch to an existing power supply, but that costs time and money, too, and results in a non-standard piece of equipment.

There don’t seem to be a large number of companies making unregulated linear power supplies – possibly because it’s easy to do yourself (if you can get an appropriate transformer) – I know of automation companies that build their own, but I don’t think it’s worth it at lower volumes, especially if you need certification. AMC and Acopian have wide ranges; others with fewer models include Logosol, Elpac, International Power, and IMS.

Since I’m writing about unique motor power supplies, IMS gets special mention – as far as I know, they are the only company to make a switch mode power supply specifically designed to power motors.  Unfortunately, they are single input voltage (120VAC or 240VAC).

Tony

I’m not a salesman, but I am happy enough with Webfaction’s hosting that when I move to WordPress 2.3 I plan on adding a referral link.

What’s nice? Now even the lowest priced plans include plenty of applications, and a good amount of bandwidth, disk space, and memory. I haven’t had any hosting problems since I’ve started.

Webfactional’s Control Panel makes it fairly easy to manage my site. If you want more control, you have to get familiar with command line Linux, but the Control Panel makes it easy to setup basic WordPress, Subversion, and Trac sites.

These features and the price make Webfaction an excellent solution for an individual (like me) or small business wanting to setup up subversion and trac sites.

Tony

What am I talking about? Using a portable 2.5″ SATA drive to store and run virtual machine images. I use the free VMWare Server, and install it on the main machines I use. I keep virtual machine images on my portable drive, and run them from the drive, instead of copying (which takes a long time).

The portable drive lets me take my PC environment with me – for example, it allows me to work at home, and conveniently keep my work life separate from my personal life.

For automation projects, of course, PC virtual machines have their limitations – they don’t simulate robots, PLC’s, or a lot of other hardware. But they can still be very useful. For example, I have a project with two similar, but different (for different hardware) sets of COM objects. They can’t both be installed at the same time (they don’t meet the requirements for side by side or registration free installation), but I can’t compile in Visual Studio unless they are registered. But I can have two different virtual machines, each one with the appropriate set of objects registered.

What I did was combine a Hitachi 7K200 7200 RPM 16M byte buffer SATA 2.5″ hard drive – currently the fastest laptop drive (see StorageReview; I bought the 100G model from ZipZoomFly) – with an eSATA/USB case (I bought a Coolmax from Fry’s for $10 after MIR; other choices include Vantec). The USB connection provides power without wall warts and the ability to connect on most PC’s, the eSATA gives high speed (about 2-3x faster than my Acomdata 80G 2.5″ drive).

I’ve found that 3.5″ external HDD’s are fine for backup, but simply too big and clumsy to move around frequently (especially with the typical external power supply and cables). Microdrives are too slow for running a VM (I’ve tried on a 8G Memorex USB drive). 1.8″ drives are interesting and would probably work OK for VM’s, but are pricer and slower than my approach. Flash memory is great for transferring data, but I don’t trust it for running VM images, because of its write cycle limit (and flash isn’t so great at small, random writes).

Standard 2.5″ portable USB drives work OK for running VM images (I’ve used the Acomdata quite a bit), but the eSATA approach gives you roughly desktop HDD speed for a bit more money. I haven’t seen any commercial eSATA 2.5″ portable drives; for that matter, I don’t know of any commercial 7200 RPM 2.5″ USB drives, so right now you have to build your own – but it’s extremely easy.

Notes:

• On Windows, I highly recommend formatting the drive using NTFS; otherwise you’ll have to have VMWare split the drive image to deal with FAT’s 2G maximum file size. All NTFS drives (USB, Firewire, eSATA) have to be stopped (e.g. via the Safely Remove Hardware icon) before they can be safely removed.
• Virtual machines love memory – on the host PC, 1G is about the minimum, 2G is much better.
• The Coolmax case quality isn’t as good as my commercial Acomdata; the drive can wiggle around. I also like Acomdata’s brushed aluminum finish better.
• 7200RPM 2.5″ drives probably won’t work with just 1 USB port for power. A USB port can provide up to 2.5W (500 mA at 5V); the 7200RPM drives typically specify at least that much power to operate. Coolmax provided a single USB port to power plug cable and a dual USB (one power, one power & communications) to 5-pin cable. I plug in the eSATA cable first, and then the USB cable so the drive always starts up in eSATA mode.
• The Hitachi drive runs a little warm, but not hot. The Acomdata drive doesn’t even get warm.
• The eSATA removal procedure is a little more involved than on USB drives. One approach is to use the hardware device manager (e.g. provide convenient link to devmgmt.msc). Sometimes SATA drives (including internal ones) show up on the Windows “Safely Remove Hardware” icon. If they don’t, sometimes the Hotswap! utility can help (it does not support all SATA controllers).
• Frequently adding/removing eSATA drives may cause problems with software activation schemes. I suspect it may be more of a problem when Windows thinks it’s a permanent (instead of removable) drive.
• The eSATA/SATA standards have their quirks. Many early add-on cards do not support hot swap; probably most early motherboards do not either. SATA is point to point, so if your motherboard comes with only 2 SATA connectors, and you’ve already got two HDD’s, you’re going to have to add an eSATA card. SATA and eSATA connectors are slightly different. The eSATA cable is better than IDE, but not as flexible (or long) as USB, although I found a 6 ft model which seems more flexible. eSATA cables seem to be $10 or more.
• Since one PC needed more SATA ports, I bought a Vantec UGT-ST300 eSATA PCI card for $30. It was the cheapest card the got good reviews and guaranteed being able to hot swap. I haven’t had any problems with it yet.
• On the other computer, I have a bracket that converts a SATA cable (from the motherboard) to an eSATA connector.
• Since eSATA is not common, it’s best if you only use a few computers regularly with the portable HDD. And it’s convenient to pre-stage the cables – have a eSATA cable and USB power cable already plugged in to the computers you use the most (and carry an extra dual USB cable with the drive for other computers).

Tony

Above is a picture of my current Logosol network, consisting of a serial to RS-485 adapter, LS-173-B drive (motion controller + server amplifier), and a LS-182X5P-1210 drive.

Logosol’s distributed control products are quirky to program and the documentation is horrible. Support is fine – when I’ve had to call, I have received good answers. Pricing is pretty good. The products have really improved over time; the LS-173, for example, only handles single ended encoders, while the latest models handle differential encoders. Most of the more recent models (including the LS-182) support Panasonic’s lovely S-series, which Panasonic has unfortunately quit making.

Another big quirk in the early models (such as the LS-173 and LS-174) is that they do not remember their settings, including the error actions. So if you want the drive to stop after it reaches a limit sensor, you have to specifically send a command to set that mode every time the drive is powered on.

Early models (e.g. LS-173) also do not have separate control power (for the motion controller) and motor power. So if you want to have an Emergency Stop, Light Curtain, or other safety device turn off all power to the motors, it will also turn off the controller. This of course makes it more difficult to ensure the drive is correctly setup at all times. It also means you will have to re-home the system, because the motion controller will not be keeping track of the motor’s position while the motor power is off.

Logosol has told me that newer models such as the LS-132 remember their settings. Newer models such as the LS-132 have separate power connections for the controller and the amplifier.

Another plus is the completeness of their distributed lineup – besides servo drives, stepper drives, servo drives with stepper inputs, spindle motor controllers, and high power I/O, they have the only distributed servo controller with an analog output (-10V to +10V) that I know of. It may sound strange to want to use a separate servo amplifier with a distributed control system, but sometimes it is necessary. For example, Nanomotion’s piezo motors only work with their servo amplifiers.

Tony

Update 5/14/2008 – Bad Panasonic! It looks like they’ve removed the list prices.  You can still get online pricing (from OnlineComponents and Allied Electronics), but it’s still stupid to remove the price list.  It was handy as a quick guide to what’s available and what it roughly costs (online searches aren’t as convenient).  By the way, local distributor pricing is often better than national catalog pricing.

I was looking at Panasonic Electric Works America’s website recently, and noticed that they now have links for suggested list price for most of their products; for example, FP Sigma PLC pricing. Note that actual prices through a distributor will typical be at least 10-20% less.

I like to have list prices, because I need to have an idea of what stuff will cost. I’m not concerned about every dollar, but it makes a big difference if a PLC is $500 or $3,000.

Tony

I just picked up an AMC DX-15 CANOpen drive (motion controller + servo amplifier) and a Logosol LS-182 drive from eBay.

Time to get practicing my CANOpen skills.

Tony