WIKA CF1H - Manual (Page 55)

Operating Instructions Temperature Indicating Controller CF1H
V 1.2
•
01/2007 - 55 -
9. Other functions
(1) Burnout alarm
(Upscale)
When the thermocouple or RTD is burnt out or the input value exceeds
[Rated scale maximum value +1 % of rated scale span], the control output
is turned OFF(main output low limit value for the current output type)
and the PV display blinks [
].
With the input RTD Pt100 (°F), if the input value is greater than 999.9, the
PV display blinks [
], however, the control is performed to [rated scale
maximum value +1 % of rated scale span].
For DC input, if the input value exceeds [scaling high limit value +10 % of
scaling span], the control output is turned OFF (main output low limit value
for the current output type) and the PV display blinks [
].
However, if the input value exceeds 9999, the PV display blinks [ ].
(Downscale)
When the input value falls to [Rated scale minimum value –1 % of rated scale span]
or less, the control output is turned OFF (main output low limit value
for the current output type), and the PV display blinks [
].
For the Thermocouple T or RTD input, if the input falls to less than –199.9,
the PV display blinks [
], however, the control is performed to [rated scale
minimum value –1 % of rated scale span].
For DC input, if the input value falls to less than [Rated scale minimum
value –1 % of rated scale span], the control output is turned OFF (main output
low limit value for the current output type), and the PV display blinks [
].
(2) Self-diagnostic function
The CPU is monitored by a watchdog timer, and when any abnormal status is
found on the CPU, the controller is switched to warm-up status.
(3) Automatic cold junction temperature compensation (Thermocouple input type)
This detects the temperature at the connecting terminal between thermocouple
and the instrument, and always keeps it on the same status at which the
reference junction is located at 0°C [32°F].
(4) Warm-up indication
For approximately 2s after the power supply to the instrument is turned on,
the type of input and the unit are indicated on the PV display, and the
maximum input rated value (for DC input, scaling high limit value) on the SV display.
(5) Setting value ramp function
When the main setting value is adjusted, it approaches the new setting value
by the set rate of change.
When the power is turned on, the control starts from the PV (process variable)
and approaches the main setting value by the rate of change.