3
9200B Flow Computer
Excitation Voltage
Menu Selectable: 5, 12, 24 VDC @ 100 mA (fault
protected)
Auxillary DC Supply with High Current Capability
24 VDC 420 mA (600 mA Peak)
Relay Outputs
The relay outputs are menu assignable to
(Individually for each relay) Low Rate Alarm, Hi
Rate Alarm, Prewarn Alarm, Preset Alarm or General
purpose warning (security), low temperature/high
temperature.
Number of relays: 2 (4 optional)
Contact Style: Form C contacts
Contact Ratings: 5 amp, 240 VAC or 30 VDC
Serial Communication
The serial port can be used for printing, datalogging,
modem connection and communication with a
computer.
RS-232:
Device ID: 01-99
Baud Rates: 300, 600, 1200, 2400, 4800, 9600,
19200
Parity: None, Odd, Even
Handshaking: None, Software, Hardware
Print Setup: Configurable print list and formatting.
Print Out: Custom form length, print headers,
print list.
Print Initialization: Print on end of batch, key
depression, interval, time of day
or remote request.
RS-485:
Device ID: 01-247
Baud Rates: 2400, 4800, 9600, 19200
Parity: None, Odd, Even
Protocol: Modbus RTU (Half Duplex)
Data Logging
The data logger captures print list information to
internal storage for aproximately 1000 transactions.
This information can be used for later uploading or
printing. Storage format is selectable for Comma-
Carriage Return or Printer formats.
Isolated Analog Output
The analog output is menu assignable to correspond
to the Uncompensated Volume Rate, Corrected
Volume Rate, Mass Rate, Temperature, Density,
Volume Total, Corrected Volume Total or Mass Total.
Type: Isolated Current Sourcing
Available Ranges: 4-20 mA, 0-20 mA
Resolution: 12 bit
Accuracy: 0.05% FS at 20°C
Update Rate: 1 update/sec minimum
Temperature Drift: Less than 200 ppm/C
Maximum Load: 1000 ohms (at nominal line voltage)
Compliance Effect: Less than .05% Span
60 Hz rejection: 40 dB minimum
Calibration: Operator assisted Learn Mode
Averaging: User entry of damping constant to
cause a smooth control action
Isolated Pulse output
The isolated pulse output is menu assignable to
Uncompensated Volume Total, Compensated
Volume Total or Mass Total
Pulse Output Form: Open Collector
Maximum On Current: 25 mA
Maximum Off Voltage: 30 VDC
Saturation Voltage: 1.0 VDC
Maximum Off Current: 0.1 mA
Pulse Duration: 10mSec or 100mSec
Pulse output buffer: 256
Fault Protection
Reverse polarity: Shunt Diode
Operating Mode
The Flow Computer can be thought of as making a
series of measurements of flow, temperature/density
sensors and then performing calculations to arrive
at a result(s) which is then updated periodically on
the display. The analog output, the pulse output,
and the alarm relays are also updated. The cycle
then repeats itself.
Step 1:Update the measurements of input signals-
Raw Input Measurements are made at each input
using equations based on input signal type selected.
The system notes the “out of range” input signal as
an alarm condition.
Step 2:Compute the Flowing Fluid Parameters-
The temperature, viscosity, and density equations
are computed as needed based on the flow equation
and input usage selected by the user.
Step 3 : Compute the Volumetric Flow-
Uncompensated flow is the term given to the flow in
volume units. The value is computed based on the
flowmeter input type selected and augmented by
any performance enhancing linearization that has
been specified by the user.
Step 4: Compute the Corrected Volume Flow at
Reference Conditions-
In the case of a corrected volume flow calculation,
the corrected volume flow is computed as required
by the selected compensation equation.
Step 5 : Compute the Mass Flow-
All required information is now available to compute
the mass flow rate as volume flow times density.
Step 6: Check Flow Alarms-
The flow alarm functions have been assigned to
one of the above flow rates during the setup of the
instrument. A comparison is now made by comparing
the current flow rates against the specified hi and
low limits.
Step 7: Compute the Analog Output-
This designated flow rate value is now used to
compute the analog output.
Step 8: Compute the Flow Totals by Summation-
A flow total increment is computed for each flow
rate. This increment is computed by multiplying the
respective flow rate by a time base scaler and then
summing. The totalizer format also includes
provisions for total rollover.
Step 9: Total Preset Comparisons-
The total associated with a preset function is then
compared against the corresponding preset value
and any required control actions taken.
Step 10: Pulse Output Service-
The pulse output is next updated by scaling the total
increment which has just been determined by the
pulse output scaler and summing it to any residual
pulse output amount.
Step 11: Update Display and Printer Output-
The instrument finally runs a task to update the
various table entries associated with the front panel
display and serial outputs.
