34
5.5 Dwell
Timer
A dwell timer (‘
TI.CFG’ = ‘DwEll’) is used to
control a process at a fixed temperature for a defined
period.
In reset the controller behaviour depends on the
configuration of the END state parameter. See
opposite.
In run the heating or cooling will come on. Timing
starts when the temperature is within the threshold
‘
THRES’ of the setpoint. If the threshold is set to
OFF the timing starts immediately.
If setpoint ramping is enabled, then the ramp
completes before the timer starts.
In the END state the behaviour is determined by
the parameter ‘
END.T’ (End type):
OFF: The heating and cooling is turned OFF
(resets to Off)
Dwell: Controls at setpoint1 (resets to Setpoint 1)
SP2 Controls at setpoint 2 (resets to Setpoint 1)
Note: The dwell period can be reduced or increased
while the timer is running.
RUN
END
RESET Digital Input
TIMER END
OFF
End State
e n d . t
=
OFF
SP2
dwel
SP2
Temp
SP1
Time
THRES = + n
OFF TIMER
RUNNING
OFF
Scrolling message
Counting
down
