Process Control
January 2023
•
Rev. 0
• Standard Devices User Manual
22
Control Deadband for Pressure Control
MENU
→
CONTROL
→
Control Loop
→
Control Deadband
The control deadband is designed to minimize the amount
of gas exhausted and improve stability. There is no active
control within the deadband setting.
✓
Note:
A control deadband cannot be set when the
device is configured to control flow (
).
If control is set to mass flow, the error "
Only
active when controlling pressure
"
displays instead of the
deadband menu
.
To turn on the control deadband, enter a non-zero value in
CONTROL
→
Control Deadband
→
Deadband
. The controller
must first reach the setpoint for the deadband to engage. If
the process variable drifts outside a deadband limit, active
control resumes until the setpoint is reached again.
The controller can be set to either hold the current valve
position or close the valve(s) in
CONTROL
→
Control Loop
→
Control Deadband
→
When in Band
. It is recommended to
hold the current position on single valve controllers and close
valves for dual valve controllers.
Example:
With a setpoint of 30 PSIA, a deadband of ±0.25
PSIA allows absolute pressure to vary between 29.75 and
30.25 PSIA.
!
Caution:
MC-Series devices do not have
an exhaust valve to reduce pressure when
pressure exceeds the deadband.
D
eadband menu
.
Choosing deadband options.
Choosing deadband size.
