RTEMS as a PLC?

[Joel Sherrill]

On 05/13/2010 08:03 PM, Ian Caddy wrote:
> Hi Aaron,
>
>
> On 14/05/2010 6:40 AM, Aaron J. Grier wrote:
>    
>> this is a long-shot, but has anybody out there done any investigation of
>> implementing IEC 61131(-3) on RTEMS to create a programmable logic
>> controller?  RTEMS seems like it would be suitable to handle both a
>> hard-real-time PLC loop in addition to human-machine-interface duties.
>>      
>
> We have used RTEMS for a number of years in a Remote Terminal Unit (RTU)
> based product (for Supervisory Control and Data Acquisition - SCADA)
> that also contains IEC61131-3 functionality.  In an RTU device the
> reporting (communications) of time based eventing is more important than
> the logic running in the unit so it is a bit different to a PLC type
> device but RTEMS had no problems performing admirably with this.
>
> We run the logic as a task with a certain priority in the system.
>
> The 61131-3 system that we use is quite old and was bought in from
> IsaGRAF but works OK.
>
> Let me know if you have any more specific questions.
>
>    
Do you know of any free software projects that relate
to this and might make sense to port to RTEMS?

--joel
> regards,
>
> Ian Caddy
>
>
>