The T100MD1616+ PLC temperature specification is 0 to 70 degree C. Some of the components are spec to -40 to+85 degree but since not all components are spec to the same temperature range, we can only spec it to the lowest common denominator, which is 0 to 70 degree C.
However, there are some customers who reportedly use the PLC at -20 degree C and there was no feedback of any particular issue encoluntered, but we can't guarantee it. So you have to test them at the lowest possible temperature that it may be exposed to before actually deploying it at temperature that are out of the specifications.
