PD8-6200 Explosion-Proof Analog Input Flow Rate/Totalizer
Instruction Manual
12
Total Reset Capabilities
The user may reset the total via a SafeTouch button,
the F4 terminal at the back of the meter, an external
contact closure on the digital inputs, automatically via
user selectable preset value and time delay, or
through serial communications.
Total Reset via SafeTouch Button
The three through-glass SafeTouch button function
keys can be programmed to reset the total and grand
total. This makes it possible for the user to reset either
the total or the grand total without opening the enclosure
cover and without the need for external devices. Of
course, if the total or grand total is password protected,
they will not reset when the function key is pressed.
Total Reset via F4 Terminal
The PD8-6200 includes a digital input (referred to as
the F4 terminal) located on the back of the electronics
module as standard that can be used to reset the total
or grand total, among other things. This is the preferred
method for externally resetting the total or grand total
because it does not interfere with the operation of the
SafeTouch buttons for programming as described
below in the Total Reset via Digital Input section.
Total Reset via Digital Input
In addition to the F4 digital input described above, the
PD8-6200 also includes four digital inputs that can be
used to reset the total or grand total. However, if a
digital input is used to reset the total, or for some
other purpose, the corresponding through-glass
SafeTouch button will function as a programming key.
Total Reset via Preset Value
The total and grand total can be programmed for
automatic or manual reset based on a preset value
determined by the user. In the automatic reset mode,
a programmable time delay is available to reset the
total or grand total after the assigned preset is reached.
Total Reset via Serial
Communications
The total and grand total can be reset via serial
communications such as a Modbus command.
Sampling Function
(PV Triggered Timed Relay)
The sampling function allows the operator to program
a set point for a “sampling” relay. When the process
(rate or total) reaches that set point, it will close that
relay’s contacts for a preset period of time (0.1 to
5999.9 seconds). An example of its use may be for
wastewater sampling. When the wastewater total
reaches a preset total interval (i.e. every 10,000
gallons), the relay contacts would close for a preset
time, and by some means (light, horn, etc.) alert
someone to take a sample, or provide the trigger to
automatically take a sample of the wastewater.
The utility of this function can, of course, be expanded
beyond sampling and be used whenever a timed relay
output closure is required when the rate or a total
interval reaches a certain set point.
Open Channel Flow
The PD8-6200, in combination with an ultrasonic level
transmitter, makes for an economical way to measure
and display open channel flow rate and total in most
weirs and flumes and take periodic samples. All the user
needs to do is enter the exponent for the weir or flume
into the PD8-6200 and the meter automatically raises
the input signal to that power. Sampling can be based
on the total flow or the flow rate. For instance, to display
open channel flow rate and total from a 3" Parshall flume
and take a one pint sample every 100,000 gallons, the
user would program the PD8-6200 as follows:
Function
Desire
Programming
Open
Channel
Flow
3" Parshall flume
Set Programmable
Exponent to 1.547
Flow Rate
Millions of
Gallons per Day
(MGD)
Set 4 mA = 0
& 20 mA = 3.508
Time base = Day
Total
Millions of
Gallons
Set Totalizer
Conversion Factor = 1
(password protect
total reset)
Non-
Resettable
Grand Total
Program meter
so grand total can
never be reset
Set non-resettable
grand total password
Display
Display Flow
Rate and Total
at the same time
Set main display for
Grand Total and second
display to toggle
between rate and total.
Sampling
Take a 1 pint
sample every
100,000 gallons
Set up relay for
sampling and to trip
every 0.1 million
gallons. Set up
sampling time such
that 1 pint is sampled.