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FC-21 Flow Computer
Acknowledge & Clear Alarms
Acknowledge is used to clear alarm relays and remove any visual alarm messages from the display. In
the run mode, press the ENTER key or activate CONTROL INPUT 3 (if set for
ACK
) to momentarily
clear alarms and alarm messages. Alarms will reassert themselves if alarm conditions are still present.
Analog Output
The analog signal (4-20mA) that is generated by the FC-21. It can correspond to the Rate, Total,
Temperature or Density. This output is used primarily for transmission of process information to remote
systems.
Audit Trail
The audit trail is used to track the number of changes made to the units setup program.
Auto Batch Restart
The Auto Batch Restart function allows the user to set an amount of time to automatically restart a batch
after the completion of a batch. This time can be set from 1 to 99 seconds.
Batch Count Mode
Batch Count Mode specifies the user preference for count direction. The "
Up
" selection begins with a
value of "0" and counts up until the batch size is reached. The "
Down
" selection begins with a value
equal to the desired batch size and counts down to "0".
Batch Overrun
The FC-21 offers a batch overrun compensation routine. If batch overrun occurs due to slow valve
response time, the unit will compensate for the overrun amount on the next batch. This feature can be
disabled if desired.
Batcher
An instrument which controls the dispensing of desired batch amounts. Liquid batching systems are
usually comprised of a batch controller (batcher), flowmeter and control valve. The batcher opens and
closes the valve through the use of relays and measures the amounts of liquid being dispensed via the
flowmeter.
Baud Rate
The speed of serial communication transmissions, expressed in bits per second.
C-Factor
(Fluid Expansion Factor)
A parameter in a flow equation which is used to describe the relationship between density or volume and
temperature changes.
Corrected Volume Flow
The equivalently volume at a reference temperature condition which involves the measurement of liquid
volume flow using a flow sensor and temperature sensor to compensate for thermal expansion.
Custody Transfer
Weights and Measure metering codes often specify several requirements for instruments and
mechanisms to prevent and track changes in the setup of an instrument which may be used in the
commercial sale of goods. The FC-21 tracks changes via the Audit Trail.
Data Logger
The capturing of information for later use and the mechanism for specifying the conditions where a
capture should be made.
DC Output / Excitation Voltage
An on-board DC power supply used to power peripheral sensors. The FC-21 offers excitation voltages
of 5VDC, 12VDC or 24VDC when powered by AC voltage.
Default Value
The value to be used by the instrument if a sensor failure or out of ranch signal is detected.
Expansion Factor
See C-Factor
Flow Alarm
A visual indication that the volumetric flowrate is above or below the flow alarm setpoint specified by
the user.
12. Glossary Of Terms
