Emerson Model 1700 Manuel D’Utilisation

3.

Set Flow Switch Setpoint to the value at which the flow switch will be triggered (after
Hysteresis

 is applied).

•

If the flow rate is below this value, the discrete output is ON.

•

If the flow rate is above this value, the discrete output is OFF.

4.

Set Hysteresis to the percentage of variation above and below the setpoint that will
operate as a deadband.

Hysteresis

 defines a range around the setpoint within which the flow switch will not

change. The default is 5%. The valid range is 0.1% to 10%.

Example: If Flow Switch Setpoint = 100 g/sec and Hysteresis = 5%, and the first measured
flow rate is above 100 g/sec, the discrete output is OFF. It will remain OFF unless the
flow rate drops below 95 g/sec. If this happens, the discrete output will turn ON, and
remain ON until the flow rate rises above 105 g/sec. At this point it turns OFF and
will remain OFF until the flow rate drops below 95 g/sec.

6.4.2

Configure Discrete Output Polarity

Display (standard)

OFF-LINE MAINT

 > OFF-LINE CONFG > IO > CH B > DO > POLAR

Chinese-language
display

Offline Maintain

 > Configuration > Input/Output > Channel B Setup > Discrete Output > Polarity

ProLink II

ProLink

 > Configuration > Frequency/Discrete Output > Discrete Output > DO Polarity

ProLink III

Device Tools

 > Configuration > I/O > Outputs > Discrete Output

Field Communicator Configure > Manual Setup > Inputs/Outputs > Discrete Output > DO Polarity

Discrete outputs have two states: ON (active) and OFF (inactive). Two different voltage
levels are used to represent these states. Discrete Output Polarity controls which voltage level
represents which state.

Set Discrete Output Polarity as desired.

The default setting is Active High.

Integrate the meter with the control system

96