INTRODUCTION
I-E96-314A
2 - 1
SECTION 2 - THEORY OF OPERATION
INTRODUCTION
This section explains the operation of the frequency counter
slave. It gives an overview of the frequency counter slave mod-
ule and related modules within a process control system and
explains the operation of the module circuitry.
CONTROL LOOP OPERATION
The Frequency Counter Slave (FCS), Hydraulic Servo Slave
(HSS) and Multi-Function Processor (MFP) form the controlling
segment of a closed loop system for turbine speed control. The
MFP is the master module and directs the control process. The
FCS and HSS are slaves that interface the process to the MFP.
Figure
shows a diagram of the turbine speed control loop
and the control signals to and from the process.
Figure 2-1. Turbine Speed Control Loop
FCS
HSS
MFP
TURBINE SPEED
MODULE STATUS
ALARMS
MAGNETIC
PICKUP
FUEL
THROTTLE
VALVE
TURBINE
LVDT
PRIMARY
LVDT
SECONDARY
HYDRAULIC
ACTUATOR
SERVO
VALVE
POSITION
FEEDBACK
MODULE STATUS
DATA
REQUEST
CONFIGURE
SYSTEM
ALARMS
TP25013A
OPERATOR
INTERFACE
MONITOR
TURBINE SPEED
MANUAL CONTROL
POSITION
DEMAND
