[Etherlab-users] What Hardware

Sebastien BLANCHET blanchet at iram.fr
Mon Feb 15 18:49:18 CET 2021


For the EtherCAT IO, you can buy Beckhoff ELxxxx terminals
because they work directly with IgH EtherCAT master.

For the coupler the standard EK1100 is very good. If you need to run 
over fiber optic, Beckhoff has also fiber optic model like EK1501

For the RS232 interface

- The easier solution is to use physical serial port or USB-RS232 adapters

- Beckhoff Serial-Over-EtherCAT module (EL6002) work only
with TwinCAT or with IgH EtherCAT master in **KERNEL** mode.

It would be easier to drive your other I/O in user mode with the 
libethercat.so library, but maybe you can run one EtherCAT controller in 
kernel mode for the serial ports and the other one in user mode for the 
others I/O. I do not know if it works because I have never tried such a 

- MOXA sells nice serial-over-ethernet adapter but their NPREAL driver 
is not compatible yet with PREEMPT-RT kernel, so you have to drive the 
serial port from another computer

For cycle time between 1 and 10ms, you can use a PREEMPT-RT Linux 
kernel, and run your control program in user mode.

- For 10ms you can use the generic Ethernet driver
- For 1ms you must use an optimized Ethernet driver (actually e1000, 
e1000e or r8169)

You can use a PC desktop for the development but for the production an 
industrial or server computer is prefereable.

The main advantage of Beckhoff IPC are
- very robust
- 24VDC power supply
- very long lifecycle: you can buy exactly the same model for 10 years.
- they can repair the IPC during 20 years.

The only drawback: they lack of IPMI for remote management.
My prefered models are the C6920 or C6930 with the optional plug-in card 

If you need an IPMI interface for remote management, a compact 
Supermicro server with a Xeon-D processor is also an interesting option

It is cheaper than Beckhoff computer and you have an IPMI interface for 
remote management. But the lifecycle is only 5 years, so you have to buy 
spares for the life

Beckhoff has a new product called "TwinCAT/BSD" that may interest you. 
It is TwinCAT + FreeBSD.

I have never tried yet, but if I have to start a new project from 
scratch with EtherCAT, it would be a serious design option.

Sebastien BLANCHET

Le 15/02/2021 à 16:26, Karl Zeilhofer a écrit :
> Hello users of EtherLab!
> We are planing a retrofit a control system in the industrial field with
> EtherCAT components.
> * 500 digital I/Os
> * 4 Analog Inputs
> * 15 Analog Outputs
> * SSI Input
> * Some 9.6kbaud RS232 ports
> Cycle Time should be in the range of 1 to 10ms.
> What hardware would you recommend?
> I have an offer for a Beckhoff IPC for around 2.000€ for an Core i7 with
> 4 LAN ports.
> Another offer is about 800€ for a similar desktop system.
> How critical is the decision for or against the supported Ethernet chip
> sets (e1000, e1000e or r8169)? Would the generic driver be sufficient?
> Kind regards,
> Karl Zeilhofer

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