OVERVIEW
I-E96-314A
1 - 1
SECTION 1 - INTRODUCTION
OVERVIEW
The Frequency Counter Slave Module (IMFCS01) is a single
channel frequency input for the Multi-Function Processor
(MFP) or Multi-Function Controller (MFC) modules. The FCS
conditions, converts and processes pulse inputs from a mag-
netic pickup attached to the front standard of a steam or gas
turbine. The converted digital data represents a count of the
input pulses and the period of the count. The MFP or MFC uses
the data to calculate frequency and consequently turbine
speed. The FCS provides exceptional frequency counting accu-
racy required by steam or gas turbine control systems.
INTENDED USER
Anyone who installs, operates, or maintains the FCS module
should read and understand the contents of this manual.
Installation and troubleshooting of the FCS requires a techni-
cian or engineer with electrical experience.
HARDWARE DESCRIPTION
The FCS is a smart module, having an on-board microproces-
sor and memory to process input data and communicate with
the controller. It consists of a printed circuit board with a face-
plate and mounts in one slot of the Module Mounting Unit
(MMU). The FCS receives power and links to the slave expander
bus via the module mounting unit backplane. Field connection
is made through a cable to a termination unit or module.
HARDWARE APPLICATION
One application of the frequency counter slave is turbine speed
control. The FCS converts pulse inputs from a magnetic sens-
ing device on a turbine into digital data and sends the data to
the MFP or MFC through the slave expander bus. The control
module calculates turbine speed using the data the FCS pro-
vides. The configuration within the control module uses the
calculated speed to control servo valve outputs according to
the user's control strategy. Figure
shows an example of a
FCS application.
In most applications, the FCS works with the Hydraulic Servo
Slave (IMHSS01). The HSS allows the operator to position
(manual or automatic) a hydraulic actuator using a servo
valve. The hydraulic actuator positions a gas turbine fuel valve
or steam turbine governor valve. As the valve opens or closes, it
regulates the fuel or steam flow to the turbine thus controlling
the turbine speed.
