4 ms·

I can see a niche for these units in some IoT and small/simple control applications. But they are close enough in price to Beckhoff's ARM-based industrial PC /

I can see a niche for these units in some IoT and small/simple control applications. But they are close enough in price to Beckhoff's ARM-based industrial PC / PLC's that I would tend towards Beckhoff for pretty much anything I wanted to do (especially now that Beckhoff offers FreeBSD instead of windows embedded). Note that Beckhoff offers both a hard-real-time PLC and a soft-realtime general computing environment on their PLC's. You can program the PLC side in standard PLC languages or C/C++ (with some limits on available syntax). On the soft-real-time side, you can pick any programming approach you want (C/C++/C#/Python/MATLAB/Labview/Elixir/TS or JS, etc.) and communicate to the hard-real-time side via a variety of options.

elteto 7y ago
Ah, so Beckhoff finally got around to add another OS besides Windows. They teased us with promises of Linux support for a while, but it took them too long and we already had experience with NI cRIOs so we just used that for our project.
LeifCarrotson 7y ago
What kind of of pricing are you getting on these (and what base model CX unit did you select) that they're 'close enough'? I'm at a Rockwell shop getting 5069-L306 PLCs for just under $1000 (which is a pretty good rate), and have only gotten list-price quotes for a handful of Beckhoff parts. I wish they'd just publish a price list and discount schedule. They wanted a lot more than $500 for a CX5020 or CX9020 last I looked.
- cashsterling 7y ago
  Unfortunately, I don't have current detailed pricing for Beckhoff's lowest end. I, too, wish they would just publish pricing. IIRC, low end beckoff arm controllers do get down to 400-500 USD. A CX9020 1GHz A8 based unit, with win embedded compact edition runs about 1000 USD with the runtime. As I understand it, this is the lowest end unit system for basic multi-axis motion control. Keep in mind that this is actually a lot of computational horsepower. When beckhoff says "basic" that means mid range for most other PLC's. For complete honesty... I ended up using a Galil motion controller rather than the Beckhoff ARM unit mentioned above, but that was due to really tight form-factor issues. Technically, the Beckhoff unit would have been better. The overall hardware cost was moreorless a wash between Galil and Beckhoff.
colorado-anon-6 7y ago
Q: What is the Beckhoff "variety of options" for communicating to the hard real-time side from (userspace?) soft-real-time side? As far as I know, all communication goes through ADS which is handled between cycles and isn't guaranteed to be even close to soft-real-time if the PC is busy. I'm genuinely interested if I'm missing a communication path here... I leveraged R3IO in TwinCAT2 to externally clock data into the task images from userspace for "soft-real-time" approx 10ms cycles , but TwinCAT3 droppped that option... My experiments and working with Beckhoff resources showed that ADS can't make that cyclic guarantee. (soft-real-time motion control application running in user-space)
- cashsterling 7y ago
  Beckhoff now also offers a direct TCP/IP socket interface (for extra money, of course) if ADS doesn't cut it for you application. You'd have to ask Beckhoff or test for yourself. Depending upon whats going on on PC level, I think sub 10ms round trip is fairly typical. I should think the TCP/IP interface will be PLC cycle-time limited (PLC cycle time of 1ms is typical) plus some fractional overhead from the TCP/IP processes themselves.

elteto 7y ago

Ah, so Beckhoff finally got around to add another OS besides Windows. They teased us with promises of Linux support for a while, but it took them too long and we already had experience with NI cRIOs so we just used that for our project.

LeifCarrotson 7y ago

What kind of of pricing are you getting on these (and what base model CX unit did you select) that they're 'close enough'? I'm at a Rockwell shop getting 5069-L306 PLCs for just under $1000 (which is a pretty good rate), and have only gotten list-price quotes for a handful of Beckhoff parts. I wish they'd just publish a price list and discount schedule. They wanted a lot more than $500 for a CX5020 or CX9020 last I looked.

cashsterling 7y ago
Unfortunately, I don't have current detailed pricing for Beckhoff's lowest end. I, too, wish they would just publish pricing. IIRC, low end beckoff arm controllers do get down to 400-500 USD. A CX9020 1GHz A8 based unit, with win embedded compact edition runs about 1000 USD with the runtime. As I understand it, this is the lowest end unit system for basic multi-axis motion control. Keep in mind that this is actually a lot of computational horsepower. When beckhoff says "basic" that means mid range for most other PLC's. For complete honesty... I ended up using a Galil motion controller rather than the Beckhoff ARM unit mentioned above, but that was due to really tight form-factor issues. Technically, the Beckhoff unit would have been better. The overall hardware cost was moreorless a wash between Galil and Beckhoff.

colorado-anon-6 7y ago

Q: What is the Beckhoff "variety of options" for communicating to the hard real-time side from (userspace?) soft-real-time side? As far as I know, all communication goes through ADS which is handled between cycles and isn't guaranteed to be even close to soft-real-time if the PC is busy. I'm genuinely interested if I'm missing a communication path here... I leveraged R3IO in TwinCAT2 to externally clock data into the task images from userspace for "soft-real-time" approx 10ms cycles , but TwinCAT3 droppped that option... My experiments and working with Beckhoff resources showed that ADS can't make that cyclic guarantee. (soft-real-time motion control application running in user-space)

cashsterling 7y ago
Beckhoff now also offers a direct TCP/IP socket interface (for extra money, of course) if ADS doesn't cut it for you application. You'd have to ask Beckhoff or test for yourself. Depending upon whats going on on PC level, I think sub 10ms round trip is fairly typical. I should think the TCP/IP interface will be PLC cycle-time limited (PLC cycle time of 1ms is typical) plus some fractional overhead from the TCP/IP processes themselves.