Instruction Manual PUC 28
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5.5.3 Alarm acknowledgement [ RELAY / ACKNOWLEDGE ]
In the alarm state (exceeding the upper limits or dropping below the lower limits), relay 1 or
relay 2 is activated. Under consideration of the activation and deactivation delays, the relays
remain energized as long as the alarm state persists. If this behaviour is not desired (e.g.,
because a loud horn is connected to the relay outputs), the alarm acknowledgement can be
activated.
If “Acknowledge” is activated, the alarm is confirmed by pressing one of the four keys. This not
only switches off the internally generated acoustic alarm but also deactivates both relays. That
means that exactly those limit violations will be acknowledged which are active at the time of
the acknowledgement. The alarm (acoustic alarm and relay activation) is triggered again if an
additionally limit is violated or an existing limit violation is acknowledged and triggered again.
Parameter
Range of values
Default setting
Acknowledge
ON
OFF
OFF
Table 19: Relay acknowledgement parameter description
5.6 Re-Calibration [ TEACH ]
The PUC 28/K has the feature to re-calibrate the pressure measurement without the need of
removing the device out of its environment. For that purpose, on the front side of the device
two pressure input ports are located
which are marked with “+” and “-“.
In case after a certain time of operation a re-calibration should be instructed, at first one of the
two menu items “TEACH” has to be called, depending if the positive or the negative range
should be re-calibrated. In each case the maximum pressure is being calibrated, thus +100Pa
resp. +250Pa for the positive range or -100Pa resp. -250Pa for the negative range.
After selecting this menu item by pressing “Enter”, a confirmation message with the selections
“no” and “yes” appears. At first, “no” is selected. With the keys “Scroll up” or “Scroll right”
select “yes” and confirm with “Enter”.
The pressure measurement now switches to the input at the front side. Now the calibration
pressure has to be applied from outside. Keep watch that the applied pressure is not too high
(±120Pa for the 100Pa device; ±300Pa for the 250Pa device). Otherwise the device might be
damaged.
As soon as the pressure applies stable (no more transient oscillations), again press “Enter”
(alternatively the re-
calibration might be cancelled by pressing “Menu”).
In the upper line of the display now the setting value of the calibration pressure appears, in the
middle line the message “meas. active”.
At the end of the measurement in the upper line the
result of the calibration appears (“done” or
“error”). Additionally it is prompted to remove the hoses from the calibration input. The
calibration measurement counts valid if the calibration value differs at max. ±30% of the
factory calibration (this also applies for repeated calibrations, the factory calibration always
stays remanent in the device).
For using the functions described above, also keep in mind the switching
conditions of the relays and the adjustable alarm confirmation described in
this section.
