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4
PD6620 Series
Loop Leader
Loop-Powered Rate/Totalizers
Predefined and Custom Units
The meter has six available preprogrammed unit classes,
volume
,
height
,
temperature
,
pressure
,
weight
, and
rate
. When the desired
unit class or unit of measure within a class is not available, a custom
unit may be programmed by using the (
CUSTOM
) menu.
Change Between Units without Needing to
Re-Scale the Meter
It is possible to change the display units within the selected unit class
without the need to re-scale the meter. When selecting a new unit
from within the
DISPLAY
menu (e.g. changing from gallons (
GAL
) to
liters (
L
)), the meter will automatically convert the display values to
display the new unit. If entering a custom unit (
CUSTM
), a custom
conversion factor will need to be entered.
OUTPUTS
Loop Leaders are available with two open collector outputs as
standard and two solid state relays and 4-20 mA output as options.
The open collector outputs and relays generally operate in the
same manner, with the major exception being the open collectors
are not available for batch control or sampling and the relays are
not available with pulse features. The open collectors and relays
can be controlled either automatically or manually. The alarm status
(with flashing red message) will show on the display even with no
output wired.
Two Open Collector Outputs
The Loop Leader is equipped with two NPN open collector outputs
that may be set up for pulse outputs, alarms, timed pulses, stopwatch
on/off, or disabled. Pulse outputs can be set to transmit the rate, total
or grand total. Output 2 may be used to generate a quadrature output
based on the other open collector output. An output test mode is also
selectable to generate pulses at a constant programmable frequency.
The open collectors are commonly used to generate a pulse for every
user-defined amount of flow that has been generated. For instance,
the Loop Leader can be programmed to generate a pulse for every
100 gallons of flow.
Two Optional Solid State Relays
The meter is optionally equipped with two solid state relays that may be
set up for alarms, timer, stopwatch on/off, sample or batch control. The
relays are rated at 250 VAC/DC @ 1 A for resistive loads and 75 VA @
0.6 A, 250 VAC/DC max (Safe Area only) for inductive loads. Alarms
are available based on the rate, total, grand total, or digital input.
Resetting the Open Collectors and Relays
The open collectors and relays (alarms) may be programmed to reset
in the following ways:
•
Automatic
(
AUTO
): Alarm will reset automatically once the alarm
condition has cleared.
•
Automatic/Manual
(
AUTO.MAN
): Alarm will reset automatically
once the alarm condition has cleared but can also be reset using
the Enter button (or whichever function key is set to acknowledge)
at any time.
•
Latching
(
LATCH
): Alarm must be reset manually and can be
done so at any time. Press the Enter (ACK) button at any time to
clear the alarm.
•
Latching with Reset after Cleared
(
L-CLEAR
): Alarm must be
reset manually and can only be done so after the alarm condition
has cleared. Press the Enter (ACK) button after the alarm
condition has cleared to reset the alarm.
Timer Function Application
Application Timers are used in everyday life; one of the most common
examples is the microwave oven. Industrial timers are used in
process control applications where certain events or actions need to
be controlled by time. Examples include automatic and batch control
applications, where the relay needs to be energized for a specific
length of time.
The timer fuction is available on the open collector and relay outputs;
which means that you can have up to four timers per meter. The start
and stop actions can be triggered from the setup menu or by the
function keys and digital input. The meter can be setup to display the
off/on timer count down.
There are two modes of operation:
1. Continuous Timer (Interval)
At the start of the timer the output is off and turns on after the
Off Delay elapses. The output remains on for the duration of the
On Time. The cycle repeats until the user stops the timer either
from the menu or a function key.
2. One-Shot Timer
At the start of the timer the output is off and turns on after the
Off Delay elapses. The output remains on for the duration of the
On Time. The timer stops and the cycle does not repeat.
a.
A sensor detects the bottle is in place and triggers the digital
input to start the timer
b.
The timer output controls the filling pump
c.
The On Time is set according to the time needed to fill the bottle
Optional Isolated 4-20 mA Output
The isolated analog output signal can be configured to represent
the rate, total or to retransmit the 4-20 mA signal input without the
need to scale the output. While the output is nominally 4-20 mA, the
signal will accurately accommodate under- and over-ranges from 1
to 23 mA. The output can be reverse scaled such that the meter’s
high calibration value outputs 4 mA and the meter’s low calibration
outputs 20 mA.
Sampling Relay
A relay set to sample will trigger when the total or grand total value
has incremented by a programmed amount. The relay can be
programmed to stay on for a specified amount of time. For example:
if a relay is set to sample the total with a COUNT of 1,000 and a TIME
of 10 seconds, the relay will energize for 10 seconds each time the
total increments by 1,000 (e.g. 1000, 2000, 3000).
