TS4100 temperature specification

From Technologic Systems Manuals

The TS-4100 uses the automotive grade i.MX6UL CPU across all part numbers ensuring consistent behavior across the TS-4100 line. The TS-4100 is designed using industrial components that will support -40 °C to +85 °C operation, however the CPU is rated to a max silicon junction temperature rather than an ambient temperature.

Model Junction Temp. Min. Junction Temp. Max.
TS-4100 (all models) -40 °C +125 °C

The trip points for thermal throttling are exposed vis /sys/

# Passive
cat /sys/devices/virtual/thermal/thermal_zone0/trip_point_0_temp
# Critical
cat /sys/devices/virtual/thermal/thermal_zone0/trip_point_1_temp

The current CPU silicon temperature can be read with:

cat /sys/devices/virtual/thermal/thermal_zone0/temp

The thermal driver, by default, takes no action if the CPU junction temperature exceeds the passive trip point. However, if the CPU junction exceeds the critical temperature, then the system will halt before the junction temperature exceeds the absolute max specified by the CPU:

[ 1619.447637] thermal thermal_zone0: critical temperature reached(120 C),shutting down
[  OK  ] Stopped target Graphical Interface.
[  OK  ] Closed Load/Save RF Kill Switch Status /dev/rfkill Watch.
[  OK  ] Stopped target Multi-User System.
         Stopping TS-SILO SuperCap Monitor Daemon...
         Stopping OpenBSD Secure Shell server...
[  OK  ] Stopped target Login Prompts.
         Stopping Getty on tty1...
         Stopping Login Service...
         Stopping Serial Getty on ttymxc0...