Re: Remote I/O

["Andreas Balzer" <andreas.balzer@bessy.de>]

Dear Nick Rees,

At BESSY we are testing an industrial PC (WAGO-I/O-IPC-P14 Linux 2.6,  
http://www.wago.com/wagoweb/documentation/758/eng_dat/d07580876001en.pdf).
This is a DIN-Rail mounted PLC using Linux with OSADL RT-patch and CoDeSys  
PLC software.
We are running the EPICS-Base directly on the PLC. A small library and  
device support routines are used for communication with the  
CoDeSys-Task(s).
CoDeSys ( http://www.3s-software.com/) can be used to setup communication  
to the WAGO-I/O-System  
(http://www.wago.com/wagoweb/documentation/navigate/nm0d___e.htm) as well  
as Profibus and CANopen devices...
	
Andreas


On Wed, 16 Dec 2009 13:44:54 +0100, <nick.rees@diamond.ac.uk> wrote:

> At Diamond we are considering what to use for the next generation of
> discrete I/O. Currently we have a lot of VME based hardware, but we are
> considering a good architecture for a Linux world.
>
> The model that we are considering is a soft IOC on a Linux system
> communicating over Ethernet using an open, industry standard protocol to
> distributed DIN-Rail mounted I/O points. These I/O points take in
> Ethernet and are powered from a 24V bus that will run around the
> hardware area.
>
> This eliminates any dependence on a specialized bus architecture (apart
> from Ethernet) on the Linux system, so they can be commodity PC's, and
> hopefully allows us to use widely available, cheap, industrial modules
> for I/O. It will not completely replace all of the requirements
> currently serviced by VME, but would be able to satisfy most of them,
> with the remaining few being serviced by the occasional VME system (or
> FPGA, or some other bus, or something else entirely in the future...).
>
> This email is to poll the EPICS community as to the experience people
> have had, and recommendations for and against.
>
> The sort of thing we have identified are:
>
>  1. Modbus/TCP based modules, such as the Acromag Busworks series
> http://www.acromag.com/models.cfm?Product_Function_ID=28&Category_ID=22&;
> Group_ID=2
>  2. EtherCAT base modules, such as those from Beckhoff:
> http://www.beckhoff.com/
>  3. Standard PLC systems where (as distinct from the other two), you
> take Ethernet to a PLC controller which then has a series of modules it
> talks to in a variety of possible ways.
>
> So, is anyone willing to share their experiences with these or similar
> systems,
>
> Cheers,
>
> Nick Rees
> Principal Software Engineer           Phone: +44 (0)1235-778430
> Diamond Light Source                  Fax:   +44 (0)1235-446713