Tecfluid DFD-2 - Manual (Page 2)

1. WORKING PRINCIPLE
The DFD has been designed to generate a series of output pulses proportional to the input
pulses. The relationship between the output and input pulses is:
K x I = I
i o
I
o
= Number of output pulses
I
i
= Number of input pulses
K = Correlation factor
The value of K is selected by means of BCD switches and jumpers inside the instrument.
1.1 Operating Limits
The output frequency is always less than half the input frequency, that is to say K
≤ 0.4999.
1.2 Applications
a) The correction or rationalization of the number of pulses of measuring transducers, for
example a flow meter which gives 5 pulses per litre and we wish to batch in litres, or a length
measuring equipment which gives 10 pulses per inch and we want to work in meters.
b) Batching : Logically if we can give one output pulse for every n input pulses we can use the
DFD for batching.
2. INSTALLATION
The DFD is housed in an IP40 plastic case for mounting on a panel inside an electric control panel.
The plastic case has two holes for mounting with screws to DIN 46 121 and DIN 43 660, and also it
has a snap fastener for fitting to DIN 46 277 and DIN EN 50 022 assembly rails.
Screw terminals are provided for external wiring. The terminals are protected against accidental
contact in accordance with VDE 0100 Part 750, VDE 0160 Part 100 and VBG 4.
IMPORTANT : In order to comply with the electrical safety requirements as per IEC 1010-1, the
installation of the equipment must take into account the following:
-The equipment must be installed inside an electrical mounting cabinet to avoid the possibility
that the operator may touch a connection terminal.
-A mains switch must be provided to disconnect the equipment. This switch must be marked
as the disconnecting device for the equipment and be within easy reach of the operator.
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