1. DVC 6000 Block Diagram – Travel control
Proportional
Gain
Integrator
I /P Relay
Actuator
and Valve
Minor Loop Feedback
Gain
Velocity Gain (Travel)
Σ
RSP
+
- - Relay
Valve Stem
Position
Travel
Sensor
Travel Control

2. DVC 6000 Block Diagram – Pressure control
Proportional
Gain
Integrator
I /P Relay
Actuator
and Valve
Minor Loop Feedback
Gain
Velocity Gain (Travel)
Σ
RSP
+
- - Relay
Valve Stem
Position
Travel
Sensor
Fails
Pressure control

3. • The Relay position
is detected by
sensing the
magnet on the
relay beam via a
detector on the
printed wiring
board. This sensor
is used for the
minor loop
feedback (MLFB)
reading.
Pressure control – Relay Position
Magnet