We currently have two T100MD-888+ in the field ( Oilfield Service application in Northern Alberta, Canada ) that are mounted in a sealed Dicast Aluminum cases, and carried on the Service Rigs.
The units have the more expensive Industrial temperatutre rated CPU Chipset, and in our case a 16x2 -20 deg C rated LCD.
For the LCD, we had to add a negative bias supply for contrast control
( the T100MD-888+ only has a positive supply bias for the contrast on the LCD)
We used one of the Analog inputs on the T100MD-888+ to act as a bang bang type thermostat for a heater we created using 39 , 150 ohm resistors, placed on the PCB that supports the LCD.
We tested the The T100MD-888+ at -15 Deg C. in a freezer. No issues so far with the PLC, the only thing we have to do at -20 is allow the LCD to heat up for 4-5 minutes, so that we can get a better display reponse to the changing values.
We are currently preparing two more of these systems for the field.
The T100MD-888+ is a good unit for it's price, but I would like to see a bigger brother, that has more speed, larger memory capacity, and 12 bit A/D.
Come on Tri-PLC, You can do it ....