diesel locomotive plc

hi
we have some light locomotives that are using modicon micros with a120 add on cards for engine , converter , instrumentation control.
not a real good choice for a dusty vibrating environment,
however they have worked ok for some years but as you would imagine
they are beginning to cause problems.
i am interested in finding a suitable hardened industrial plc,24vdc inputs, relay outputs with analogue i/o in a brick type.

Any suggestions?

Are you referring to the old modicon micros or the later modicon tsx micro with the telemecanique branding on?
Also need to know the io count to give a recommendation

old modicon micro they used 28 digital inputs 12 out and a couple of anolog in and out. it wasn't the best programming job and i would be seeking to minimise when i rewrite.

Well would have recommended the Twido Extreme,but it only has 22 inputs. Very robust though and free software. I can only recommend the brand we use so I would say the Modicon m340. Below is a link to their brochures and technical information
http://www.schneider-electric.com/corporate/en/products-services/automation-control/products-offer/range-presentation.page?p_function_id=18&p_family_id=234&p_range_id=1468#

Have a look at IFMs products.

http://www.ifm.com/ifmus/web/padv04_10_10_10.htm

The are made for mobile applications and I do believe they have aproval for railway traffic. The are programmed in codesys software according to IEC 61131-3.