Liquid Controls HML4-F1 - LCMag - Manual (Page 29)

HML4-F1
29
(POS. 3.3) Measure filter AC enable [AC Line fil.=ON/OFF]
This function allow to filter electrical noise on the liquid coming from the main frequency.
(POS. 3.6) Automatic scale change enable
[Autorange=ON/OFF]
Enables the automatic change of scale. The meter may have two different working ranges in order
to suit to the variable process conditions. In order to get the best results out of this function it is
important range N.2 is bigger than N.1. When the flow rate increases and reaches the 100% of the
full scale 1, then the meter automatically switches to scale 2. When the flow rate decreases again
reaching a value on scale 2 equal to the 90% of full scale N.1, then the active scale is 1 again.
Allowed values for this parameter: ON/OFF. N.B.: the autorange does not allow using the manual
change of range (pos. 5.6)
MENU 4 - ALARMS
(POS. 4.6) Current output value in case of failure [mA v.fault =% XXX]
Setting of the value the 4-20mA current output has to be in one of the following cases:
empty pipe; coils interrupted; ADC error
The allowed range is from 0 to 120% of the 0-20 mA scale, 120% corresponds to 24mA and does
not depend on the selected range (0-20/4-20mA). The NAMUR NE43 recommendation asks for a
alarms signalling value for the current output lower than 3.6mA (<18%) or bigger than 21mA
(>105%). It would then be preferable to set the value of this function at the 10%, so that the
current value in case of the a.m. cases would be 2mA, allowing the following diagnostics:
1. current < 2 mA - 5%: line interrupted, power supply failure or faulty converter;
2. 2mA -5% current 2mA + 5%: hardware alarm;
3. 4mA current 20mA: normal working range;
4. 20mA < current 22mA: out of range, measure above 100% f.s.
N.B.: To set this parameter to zero corresponds to disable the alarm
(POS. 4.7) Batch safety timer
[Timeout=s XX.X]
With this function is possible to set a maximum time for the batch; over this time will be generate
an alarm.
This function is useful when you need control one or both of the followings condition:
‰ batch valve open and flow rate is zero
‰ batch valve closed and flow rate different to zero
When this alarm is activated, they are aborted the batch operation and the power supply of the
valve. The values of function are from 0 to 25.5 seconds and is active only if one or more of the
batch functions are enable.
MENU 5 - INPUTS
(POS. 5.1-2) Modify/reset totalizer enable [T1/2 reset=ON/OFF]
When one of this function is enabled, the related totalizer may be reset through the on/off input.
(POS. 5.5) Autozero calibration external command enable
[Calibration=ON/OFF]
When this function is active, applying a voltage on the on/off input terminals the meter performs a
autozero calibration cycle. ATTENTION: if the voltage pulse is less 1 sec., the meter performs a
calibration cycle for compensate possible thermal drifts. If the voltage pulse is more 1 sec, the
meter performs a zero calibration of measure. This function enables/disables the automatic zero
calibration system. To perform the sensor it is absolutely necessary the sensor is full of liquid and
that the liquid is perfectly staying still. Even very small movement of the liquid may affect the result
of this function, and, consequently, the accuracy of the system.
(POS. 5.8-9) Functions assigned to input 2-3
[INP.2-3=XXXXXX]
Choice of the function to associate the input 2 The functions are listed in the table below.
FUNCTIONS FOR INPUTS 2-3
OFF: DISABLE
BATCH: START/STOP BATCH
BM SELECT: STATIC SELECTION OF FORMULA
VALV. OPEN: OPEN VALVE COMMAND
STAND-BY: STAND-BY COMMAND (see function 10.4)