CIRCUTOR MDC-20 - Manual (Page 29)

MDC-20
User Manual Page 29 of 58
Fig.7-11 . – Configuration of units
7.5.5 Variable limits
This menu option (see Fig.7-4) lets you configure the nominal values of the variables, as well as
a series of margins to display on screen when a variable measures values outside the
configured range, in order to easily detect anomalous values.
In the MDC-20 the limits of the variables only refer to flow values as there is no point
referencing them to either impulse or status values. For this reason the fields appear disabled if
the inputs have not been configured as flow meters.
Fig.7-12 . – Limit values setup
• Nominal Value: Indicate the nominal flow value for each channel. If the nominal value is
0, the alarm is disabled.
• Pre-alarm or lower alarm: In the channel 1 example, when the value of the variable is
between 5% and 10% below the nominal value, there will be a pre-alarm signal; if it is
below 10% the alarm will sound.
• Pre-alarm or upper alarm: In this case when the variable value is between 5% and
20% above the nominal value, there will be a pre-alarm signal; if it is above 20% the
alarm will sound. If the pre-alarm value is equal to the alarm value, the pre-alarm zone
will be disabled, passing directly from normal to alarm status.