One complaint I have about most proprietary motion control field buses is that the I/O choices available are very limited.Â Standard field buses such as CANOpen, Ethernet PowerLink, and EtherCAT have a much better selection of I/O modules as well as a wide selection of drives, but there’s one device that’s hard to find on most motion networks, proprietary as well as standard: an interface to analog servo drives.
Analog servo amps are still important because specialized equipment such as piezo motors can require you to use a custom servo amplifier, which typically has a +/- 10V analog input.Â So if you want to use these devices on a network, you’re out of luck — unless you can get a network to analog drive.
The Logosol LDCN is the only proprietary motion network I know of that has drives with an analog output (they are the LS-160, LS-170F, and LS-180).
I’ve only found one company making analog output drives for a standard motion network: the ACS Motion EtherCAT intefaces.Â ACS has various models.Â The SPiiPlusUDI modules can control 2 or 4 analog servo amps.Â The SPiiPlusPDM modules can control 2 or 4 step/dir input drives, including step/dir servo drives, stepper drives, or laser generators.
I think the UDI modules are more useful, but I’m sure the PDM modules can be handy.Â For example, if you want to use a proprietary Asian servo motor that has to be used with a proprietary drive that takes step/dir input.
Important note: after I wrote this, I had a discussion with a local ACS distributor, and he said he was pretty sure that the ACS EtherCAT drives and modulesÂ will only work with ACS motion controllers (hardware or software).Â So, if you’re interested in these modulesÂ but don’t want to go 100% ACS, please check first.
May 30, 2013 No Comments
What are the major components and why did I choose them from my stock of automation components?
- XY Table – a Parker Daedal simply because it’s the only one I own.Â I can’t find a part number on it, but it looks similar to a 806006CTE5D1L2C1M1E1.Â It’s a beefy cross roller stage with 0.2″ pitch (5 turns per inch) ballscrews and NEMA 23 motor mounts.
- Joystick – a CH Products HF22S10-U USB hall effect joystick, because it’s an awesome joystick.Â Besides, the USB interface is a lot easier to use than analog voltage or resistive interfaces.
- PC – a Shuttle X50 all-in-one because it’s compact, has a touchscreen, and has plenty of USB ports.
- CAN Interface – a Kvaser Leaf Light, because it’s really nice, I haven’t featured it before, uses a USB inteface (the X50 has no PCI slots) and it’s well supported by Copley.Â My Ixxat USB to CAN compact would also be a good choice.
- Drives – Copley Accelnet ACP-055-018 and Stepnet STP-075-07.Â I also have AMC and Elmo CANOpen servo drives, but Copley was my choice because I only have Copley stepper drives (and I want to show stepper performance versus servo performance) and only Copley includes high level software (CMO, Copley Motion Objects).
- Servo Motor – currently a MCG IB23000-E1 because this is a typical NEMA23 servo motor and I haven’t used it before, so I can describe getting an unknown servo motor up and running.Â Besides, my Emoteq BH02300’s are too fast.Â If it doesn’t work (and someone has written “Bad Hall” on it), I’ll substitute another servo motor after describing my troubleshooting.
- Stepper Motor – a Sanyo Denki Step Syn 103-771-16 because it was the first single shaft NEMA 23 stepper motor that I found.
- Power Supply – my trusty Logosol LS-1148.Â I’ll be using the E-STOP input option.
- E-STOP – a IDEC AOLD39911DN-R-24V lighted 30mm mushroom switch.Â It’s not really an E-STOP, but it should work OK, I like IDEC’s quality, and I was able to pick up a couple for a good price on eBay.
- Development Tools – SharpDevelop, because it deserves to be highlighted.Â Microsoft Visual Studio would also be a good choice, and the Express Editions are free, but SharpDevelop has some unique features that can be useful even if you already have Visual Studio.Â Besides, I’m pretty sure the download is a whole lot smaller.
I do have enough equipment that I could use a traditional motion controller (Galil or MEI) and analog servo amplifiers (AMC), but I decided to go the CANOpen distributed route because it’s a heck of a lot less wiring.
October 18, 2011 1 Comment
I think it’s interesting that there are so few switch mode power supplies (SMPS) designed for powering motors.Â Motor power requirements are different from electronics; voltage regulation isn’t critical.Â Servo motors benefit from a large current peak (overload) capability and sometimes need a shunt.Â Steppers are best with a power supply designed to handle a rapidly changing inductive load.
A typical switch mode power supply, however, is designed for tight voltage regulation, does not have a shunt and handles over current by limiting current to its maximum rating.
Some switching power supplies are better because they have 20% to 50% peak capacity for a brief time.Â I’ve seen this capability in models from Cabur (sold by ASI in the US), Puls, and Delta; I’m sure there are other examples.
I’ve used the Delta CliQ series for servo motor power, and so far they’ve worked well.Â The CliQ can handle 50% over current for 3 seconds, the pricing is quite good (under $150 for 24V at 10A), but they’re only available for 12V and 24V.
The first designed for motors SMPS I discovered was the IMS ISP200/300 series, which are unregulated switching supplies specifically designed for handling the rapidly changing, inductive loads typical of stepper motors or DC motors.Â IMS is now Schneider Electric, and they have discontinued the ISP series.
I don’t really consider the Galil PSR series a SMPS for motors; it looks like an ordinary enclosed switcher with an added shunt resistor.Â The PSR costs $250, and is available in 24V at 12A or 48V at 6A.
I recently discovered a second SMPS for motors, the Cabur XC series (sold in the US by ASI).Â They have a 72-85V output at 3.1A, 6.6A, or 13.3A, have a 20% reserve capacity when <45C, can handle 50% over current for 5 seconds, and have output over-voltage protection (equivalent to a shunt).
It’s interesting to compare the XCSF500G (72V at 6.6A) to the Logosol LS-872.Â Logosol makes my favorite linear power supplies (I own a LS-1148 and use it extensively); they are relatively compact, are switch selectable between 115V and 230V input, have ESTOP inputs, front panel mount fuses, and are available in a variety of output voltages.Â (The only other 120V/240V switch selectable linear motor power supply I’ve been able to find is Copley’sÂ DP models in their PST series, but they cost much more).
|Cabur XCSF500G||Logosol LS-872|
|Input Voltage||90-132VAC or 187-264VAC||100-120VAC or 200-240VAC (switch selectable)|
|Voltage Regulation||<1%||-10%, +15%|
|Current, Max Cont||6.7A||8A (50% duty cycle)|
|Current, Peak||10A for 5 sec||20A for 5 sec|
|Weight||2.6 lbs||9 lbs|
|Dimensions||Not listed; appears to be smaller than the LS-872||8.55″ x 6.7″ x 2.8″|
|Other features||DIN Rail Mount
Output overvoltage protection
Short circuit, overload, and over temp protection
Separate, unregulated 24V 2.5A power supply
|Approx. Price||$550||$425 (no shunt)|
October 2, 2010 No Comments
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.Â Unfortunately, they are single input voltage (120VAC or 240VAC).
Comments 4/20/2011: Copley Controls also sells switch selectable 120/240V linear motor power supplies, but I think Logosol’s are a better choice.
IMS (now part of Schneider) has dropped their switch mode power supplies (SMPS).
Carbur (sold by ASI in the US) does have some interesting SMPS for motors; see my blog post for more.
January 21, 2008 No Comments
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.
August 10, 2007 No Comments
Time to get practicing my CANOpen skills.
June 30, 2007 No Comments