THORLABS TC200 User Manual page 9

Temperature Controller
8. Sensor Alarms – The TC200 can determine whether a temperature sensing element is short circuited or
not installed (open circuit). If a short or open circuit occurs, the TEMP ACTUAL field in the main LCD display
screen will read !SENSOR! If the sensor alarm occurs during normal operation, the output will immediately
be disabled. The unit cannot become enabled again until the error is resolved.
The TC200 can only determine shorted or open sensor connections; it cannot determine if the
installed sensor does not match the programmed sensor selection. Care must be taken to ensure
that the settings match the actual sensor used, or damage will occur to the heating system.
9. Maximum Temperature Shutdown – Based on the setting of the TMAX parameter discussed above, if
the TC200 reads back a temperature value that equals or exceeds TMAX, the output relay will be opened
and !TMAX! will be displayed in the MODE field of the main LCD display screen. The controller, however,
will remain enabled. Once the system temperature lowers down to the set-point value, the output relay will
be closed, connecting the controller to the heater again. If the temperature increases past TMAX again, the
relay will open. If this cycle occurs three times, on the third time, the relay will open and the controller will
automatically disable. The TMAX text will continue to be displayed until it is cleared manually by the user
by either pressing the SELECT keypad while in the main screen, or by pressing the ENABLE keypad.
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ATTENTION
Chapter 4: Features
TTN051989-D02