Liquid Controls SP3850 - Manual (Page 70)

SP3850 Flow Computer
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Mass Flow
Mass Flow is inferred by the volumetric flow and density (or implied density) of a fluid.
Maximum Batch Preset
The Maximum Batch Preset allows the user to program the Maximum Batch value allowed to be entered by the
operator. If an operator should try to program a batch higher then this value, the unit will not allow the value to be
entered and will prompt the user with an error message saying that the Maximum Batch Preset has been exceeded.
Maximum Drain Time
The unit declares that a batch is “done” when the flow rate equals “0”. A flow rate may be present long after the
Preset Relay de-energizes due to slow reacting valves or leaky valves. The Maximum Drain Time allows the user to
enter an amount of time (0 to 99 seconds) to wait before declaring “Batch Done”. After the Preset Batch quantity is
reached, the unit will declare “Batch Done” when the flow rate is “0” or the Maximum Drain Time has expired.
The batch data will then be available for printing and datalogging.
Max Window
The max. window time sets the maximum sample time (1 to 99 sec) for the ratemeter.
Meter Expansion Coef.
A coefficient in an equation which may be used to correct for changes in flowmeter housing dimensional changes
with temperature.
Modem Init Master
The "Modem Init Master" menu allows the user to select whether the unit will engage in a configuration
conversation with the modem on power up or impart no setup information to the modem and use it "as is". For
most users it is recommended to choose "yes" for "Modem Init Master".
Parity
A method for detecting errors in transmissions of serial communications data.
Preset
A set point used to trigger the relay outputs of the SP3850.
Print Interval
The print interval allows the SP3850 to transmit information to the serial port at selectable time intervals.
Private Code
An operator password code which authorizes changes to the setup of the instrument but blocks access to the
Service/Calibration/Test mode. The private code also blocks the clearing of the Grand Total.
Process Parameters
Any sensor information which has been scaled to engineering units including Flow, Temperature, Pressure and
Density.
Pulldown (Input Termination)
The termination of an input at which the input is pulled down to ground through a resistor. Inputs that are
terminated by this method need to be driven high with a positive voltage pulse.
Pullup (Input Termination)
The termination of an input at which the input is pulled up to a positive voltage through a resistor. Inputs that are
terminated by this method need to be pulled low with a sinking current or contact to ground .
Pulse Output
The pulse output of the SP3850 is available for remote accumulation of the total or sent to peripheral devices,
such as a PLC. The output can be scaled using the Pulse Output Scaling Constant.
Quad
Abbreviation for Quadrature. Quadrature signals are used for direction control. Two flowmeter signals are output
with a 90
° phase shift. The counter counts UP when channel A precedes channel B, and counts DOWN when
Channel A lags Channel B.
Quick Setup
A utility that provides for rapid configuration of an instrument. The SP3850 quick setup provides the following:
1) Prompts the user for only critical information.
2) Automatically sets specifications to common uses.
After following the Quick Setup procedure, the unit will be operational to perform the basic measurement. The
setup can be further customized using the setup menus.
12. Glossary Of Terms (Continued)