Functional Description - Toshiba LF620 Instruction Manual

10. Functional Description

The LF62* Series Electromagnetic Flowmeter is equipped with two contact output terminals (digital
output terminals (DO1, DO2)) and one external input terminal (digital input (DI)), enabling you to use
various functions, such as pulse output and alarm output.
The following functions are provided using the digital I/O functions are described below.
Functions
Totalization
Multiple ranges
Forward and reverse ranges
High / Low alarm
High-High / Low-Low alarm
Preset counter
Remote still water
zero adjustment
Remote fixed value output
Converter failure alarm
Multi-range high
/ low alarm
Required DO, DI
Totalizes the flow volume in volumetric unit.
The totalized flow volume can be output (pulse output) for each unit
DO:1
of volume.
DI:0 or 1
The totalizer and pulse output can be controlled (start, stop and reset)
by an external signal.
Multiple measuring ranges can be selected in accordance with the flow
DO:1 or 2
rate. The measuring ranges can be selected either automatically or by
DI:0 or 1
an external signal.
Forward and reverse flows can be measured. The forward and reverse
DO:1
flow measurements can be used together with multiple ranges function.
Outputs an alarm signal when the flow rate signal exceeds or lowers
DO:1 or 2
below the preset values.
When the totalizer count exceeds its preset value, the converter
DO:1
outputs a contact output signal.
DI:1 Still water zero adjustment can be started by an external signal.
Arbitrarily fixed current output and/or fixed pulse output can be used to
DI:1 check a process loop circuit of output.
The fixed output mode can also be selected by an external signal.
The converter outputs an alarm signal if an error such as memory error
DO:1
or excitation circuit error occurs.
Working in line with upper/lower range selection by an external signal,
DO:2
high/low alarm and high-high / low-low alarm can be switched for the
DI:1
flow rate signal to output an alarm signal.
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Outline description