B-320-2-E
9
3.4 About Safety Features
The register is provided with the following safeguards:
(1) On detection of missing pulses
Either condition 1) or 2) causes the indicator "ALM" in the display to light and the shutoff valve to close
automatically for safety’s sake.
1) The register fails to count any pulses within preset missing pulse period (PL) from the moment a batch
process started.
2) Counting pulses is interrupted during a batch process and remains interrupted beyond preset missing
pulse period (PL).
The electronics starts missing pulse detection 5 seconds from the start of a batch process; actually a
missing pulse setpoint (PL) + 5 seconds is required for this function to go into effect.
Large totalizer units of measure (weights of the total count) by frequency reduction or other processing may
require more time to update the count, but such a condition will not trigger a missing pulse detection alarm.
If "0" is chosen for missing pulse setpoint (PL), the capability to detect missing pulses will remain disabled.
For manual batch processing, therefore, we recommend you to use a setpoint at "0."
(2) On detection of an overshoot (overmeasurement)
An overshoot of measurement at the end of a batch does occur due to some time lag in shutoff valve
actuation (on closure). An indicator "ALM" in the display lights when the register counts more than the
anticipated overshoot count (oV).
NOTE: While "0" is chosen for anticipated overshoot count (oV), the overshoot detection feature remains
disabled.
(3) On detection of a low battery
A weak built-in battery tells the operator with a blinking alarm "BATT" in the display. When the battery
has run down nearly to its end, the "ALM" comes on, the shutoff valve closes automatically (if in an open
position) and, at the same time, the variables (total count in a batch process and cumulative total count) are
evacuated to a nonvolatile memory.
From this moment onward, valve operation will remain inoperative (
START
▲
button will not respond). As a
rule of thumb, it takes about 8 days from a blinking "BATT" alarm till a stay-on "ALM." It is suggested that
the old battery be replaced with a new one during this period.
NOTE: A low battery when left unused for some time may restore its energy to some extent and may be
used for a batch job again, only for an unpredictable length of time. Do not fail to replace a battery
that has once caused the "ALM" to come on.
