Model M1715A Maxiflex 2PFC Module0 pages
Maxiflex 2PFC Precision Frequency Counter Module
Model M1715A 2 Channel High Precision Frequency Counter Module.
DATASHEET
FEATURES
•
2 individually Isolated Frequency Counter Channels
•
Interfaces to two Vibrating Tube Densitometers
•
Measures 1Hz to 5kHz at 15ppm accuracy
•
Outputs period of incoming frequency in nanoseconds
•
Accepts 9-30Vdc or 3 to5Vdc Pulse Input
•
Fits in any MAXIFLEX base I/O slot
•
1500V rms Isolation
The M1715A high precision frequency counter
module provides individually isolated field inputs to
two 32-bit frequency counters. The counters are
designed to operate in the range 1Hz to 5Khz and
return the period in nanoseconds of each input to
an accuracy of better then 15ppm.
A target application for this module is as interface
to vibrating tube densitometers to allow the highest
accuracy of frequency to be measured in oil and
gas custody transfer applications.
Liquid density is one of the many parameters to be
accurately measured for product quality control,
custody transfer, process control, or liquid interface
detection purposes. In the hydrocarbon industry,
the vibrating tube densitometer is most common. In
this type of densitometer, a tube of known mass is
vibrated at its natural frequency. As the tube is
filled with the process fluid, the frequency will be
damped proportionate to the density of the
material. Other variables, such as specific gravity,
molecular weight, Brix and concentration can be
derived from this measurement if required. The
mass is related to the mass of the tubing plus the
mass of the fluid inside the tubing. As the mass (or
density) of the fluid in the tubing varies, the natural
frequency varies. Because of the relative mass of
the tube to the process fluid in the tube, the
measurement of frequency must be highly accurate
to achieve satisfactory results. The high accuracy
of the Maxiflex 2PFC module makes it ideal for this
measurement application.
The 2PFC module should be used in conjunction
with dedicated software to be used as part of the
user application. For use with Isagraf compatible
CPUs use the Omniflex supplied function block
“cn74_t”. For use with Forth compatible CPUs, ask
Omniflex for the necessary eziForth words.
Each input may be configured by links inside the
module to either be a 3-5V dc, or a 9-30V dc input
to support the widest range of densitometers.
SPECIFICATIONS
Input
Environmental
Number
2 Frequency Inputs (Inputs 1 and 2)
Operating Temperature
Type (Two Ranges)
9-30Vdc (default) or 3-5Vdc Pulses
Storage Temperature
Input Current
Standard: 2.6mA at 9V; 10mA at 30V
Low: 2.6mA at 3V; 8mA at 5V
Humidity
95% max. at 40°C (104°F) non-condensing.
Input Isolation
100% tested to 1500Vac for 1 minute
Protection
Electronics conformally coated
Insulation Resistance
1000MΩ min. at 500Vdc
Input Indication
(Green LED per channel)
LED on channel Active
LED off channel Inactive
Input Range
1Hz to 5kHz
Module ID
126
Period Measurement Range
200,000 to 1,000,000,000 nanosec.
Scan Code
127
Screw Terminal Wire Size
-40°C to +70°C (-40°F to +158°F)
Logic Power Consumption
From Logic Power Supply
60mA from 5Vdc max.
Auto Identification Codes
Mass
InputTermination
Types
-25°C to +60°C (-13°F to +140°F)
Screw clamp Plug-in Terminal Blocks
and 20 way ribbon header
Excluding Packaging
320g (11.3oz)
Including Packaging
410g (14.5oz)
2
2.0mm maximum
For manageable wiring to the module, 0.5
mm2 is recommended with 2mm overall
outside diameter
Ordering Information
Model
Order Code
Maxiflex 2PFC
M1715A
Copyright Omniflex ♦ Subject to change without notice
Datasheet DSM1715AR02 sheet 1 of 2
http://www.omniflex.com
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