Toshiba lf516 User Manual

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10. Functional Description 
 
The LF516/LF546 Electromagnetic Flowmeter is equipped with two contact output terminals (digital 
output terminals (DO1, DO2)) and one external input terminal (digital input (DI), optional), 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 
Required DO, DI
Outline description 
Totalization 
DO:1       
DI:0 or 1 
Totalizes the flow volume in volumetric unit. 
The totalized flow volume can be output (pulse output) for each unit 
of volume. 
The totalizer and pulse output can be controlled (start, stop and reset) 
by an external signal. 
Multiple ranges 
DO:1 or 2 
DI:0 or 1 
Multiple measuring ranges can be selected in accordance with the flow 
rate. The measuring ranges can be selected either automatically or by 
an external signal. 
Forward and reverse ranges 
DO:1 
Forward and reverse flows can be measured. The forward and reverse 
flow measurements can be used together with multiple ranges function.
High / Low alarm 
High-High / Low-Low alarm
DO:1 or 2 
Outputs an alarm signal when the flow rate signal exceeds or lowers 
below the preset values. 
Preset counter 
DO:1 
When the totalizer count exceeds its preset value, the converter 
outputs a contact output signal. 
Remote still water   
zero adjustment 
DI:1 
Still water zero adjustment can be started by an external signal. 
Remote fixed value output 
DI:1 
Arbitrarily fixed current output and/or fixed pulse output can be used to 
check a process loop circuit of output. 
The fixed output mode can also be selected by an external signal. 
Converter failure alarm 
DO:1 
The converter outputs an alarm signal if an error such as memory error 
or excitation circuit error occurs. 
 Multi-range high  
/ low alarm (option) 
DO:2 
DI:1 
Working in line with upper/lower range selection by an external signal, 
high/low alarm and high-high / low-low alarm can be switched for the 
flow rate signal to output an alarm signal.