Emerson MMI-20019043 User Manual
Configure Flow Switch parameters
Display
OFF-LINE MAINT
> OFF-LINE CONFG > IO > CH B > SET DO > CONFIG FL SW
ProLink II
•
ProLink
> Configuration > Flow > Flow Switch Variable
•
ProLink
> Configuration > Flow > Flow Switch Setpoint
•
ProLink
> Configuration > Flow > Flow Switch Hysteresis
ProLink III
Device Tools
> Configuration > I/O > Outputs > Discrete Output
Field Communicator
•
Configure
> Manual Setup > Inputs/Outputs > Discrete Output > Flow Switch Source
•
Configure
> Manual Setup > Inputs/Outputs > Discrete Output > Flow Switch Setpoint
•
Configure
> Manual Setup > Inputs/Outputs > Discrete Output > Hysteresis
Overview
Flow Switch
is used to indicate that the flow rate (measured by the configured flow variable)
has moved past the configured setpoint, in either direction. The flow switch is
implemented with a user-configurable hysteresis.
implemented with a user-configurable hysteresis.
Procedure
1.
Set Discrete Output Source to Flow Switch, if you have not already done so.
2.
Set Flow Switch Variable to the flow variable that you want to use to control the flow
switch.
switch.
3.
Set Flow Switch Setpoint to the value at which the flow switch will be triggered (after
Hysteresis
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.
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.
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.
Integrate the meter with the control system
Configuration and Use Manual
117