3-Phase Counter Without Separate Error Signal; 2-Phase Counter With Separate Error Signal - Proces-Data PD 340 Manual

7.1

3-phase counter without separate error signal

This mode indicates the flow rate by means of 3-phase pulse signals. The phase sequence
indicates the flow direction and the pulse frequency indicates the flow rate. An error in the
Flow Transmitter will open the three output signals (high-impedance state). See the first of
the signal diagrams below. In the second diagram, backward flow alters the sequence of
the output signals. Apart from the phase sequence, the functionality for backward flow is
the same as for forward flow.
7.2

2-phase counter with separate error signal

This mode indicates the flow rate by means of 2-phase pulse signals. The error signal is
closed circuit during error-free measurement. The phase sequence indicates the flow direc-
tion and the pulse frequency indicates the flow rate. An error in the Flow Transmitter will
open the three output signals (high-impedance state), i.e. the error signal and both pulse
signals. See the first of the signal diagrams below. In the second diagram, a backward flow
alters the sequence of the two pulse signals. Apart from the phase sequence, the function-
ality for backward flow is the same as for forward flow.
Manual Flow Transmitter, PD 340
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