Bailey Infi 90 IMHSS02 User manual

®
®
Process Control and
Automation Solutions
from Elsag Bailey Group
E96-315
Hydraulic Servo Slave Module
(IMHSS02)

WARNING notices as used in this instruction apply to hazards or unsafe practices that could result in
personal injury or death.
CAUTION notices apply to hazards or unsafe practices that could result in property damage.
NOTES highlight procedures and contain information that assists the operator in understanding the
information contained in this instruction.
WARNING
INSTRUCTION MANUALS
DO NOT INSTALL, MAINTAIN, OR OPERATE THIS EQUIPMENT WITHOUT READING, UNDERSTANDING,
AND FOLLOWING THE PROPER Elsag Bailey INSTRUCTIONS AND MANUALS; OTHERWISE, INJURY OR
DAMAGE MAY RESULT.
RADIO FREQUENCY INTERFERENCE
MOST ELECTRONIC EQUIPMENT IS INFLUENCED BY RADIO FREQUENCY INTERFERENCE (RFI). CAU-
TION SHOULD BE EXERCISED WITH REGARD TO THE USE OF PORTABLE COMMUNICATIONS EQUIP-
MENT IN THE AREA AROUND SUCH EQUIPMENT. PRUDENT PRACTICE DICTATES THAT SIGNS
SHOULD BE POSTED IN THE VICINITY OF THE EQUIPMENT CAUTIONING AGAINST THE USE OF POR-
TABLE COMMUNICATIONS EQUIPMENT.
POSSIBLE PROCESS UPSETS
MAINTENANCE MUST BE PERFORMED ONLY BY QUALIFIED PERSONNEL AND ONLY AFTER SECURING
EQUIPMENT CONTROLLED BY THIS PRODUCT. ADJUSTING OR REMOVING THIS PRODUCT WHILE IT IS
IN THE SYSTEM MAY UPSET THE PROCESS BEING CONTROLLED. SOME PROCESS UPSETS MAY
CAUSE INJURY OR DAMAGE.
AVERTISSEMENT
MANUELS D’OPÉRATION
NE PAS METTRE EN PLACE, RÉPARER OU FAIRE FONCTIONNER L’ÉQUIPEMENT SANS AVOIR LU,
COMPRIS ET SUIVI LES INSTRUCTIONS RÉGLEMENTAIRES DE Elsag Bailey. TOUTE NÉGLIGENCE À
CET ÉGARD POURRAIT ÊTRE UNE CAUSE D’ACCIDENT OU DE DÉFAILLANCE DU MATÉRIEL.
PERTURBATIONS PAR FRÉQUENCE RADIO
LA PLUPART DES ÉQUIPEMENTS ÉLECTRONIQUES SONT SENSIBLES AUX PERTURBATIONS PAR
FRÉQUENCE RADIO. DES PRÉCAUTIONS DEVRONT ÊTRE PRISES LORS DE L’UTILISATION DU MATÉ-
RIEL DE COMMUNICATION PORTATIF. LA PRUDENCE EXIGE QUE LES PRÉCAUTIONS À PRENDRE
DANS CE CAS SOIENT SIGNALÉES AUX ENDROITS VOULUS DANS VOTRE USINE.
PERTURBATIONS DU PROCÉDÉ
L’ENTRETIEN DOIT ÊTRE ASSURÉ PAR UNE PERSONNE QUALIFIÉE EN CONSIDÉRANT L’ASPECT
SÉCURITAIRE DES ÉQUIPEMENTS CONTRÔLÉS PAR CE PRODUIT. L’AJUSTEMENT ET/OU L’EXTRAC-
TION DE CE PRODUIT PEUT OCCASIONNER DES À-COUPS AU PROCÉDÉ CONTRÔLE LORSQU’IL EST
INSÉRÉ DANS UNE SYSTÈME ACTIF. CES À-COUPS PEUVENT ÉGALEMENT OCCASIONNER DES
BLESSURES OU DES DOMMAGES MATÉREILS.
NOTICE
The information contained in this document is subject to change without notice.
Elsag Bailey, its affiliates, employees, and agents, and the authors and contributors to this publication specif-
ically disclaim all liabilities and warranties, express and implied (including warranties of merchantability and
fitness for a particular purpose), for the accuracy, currency, completeness, and/or reliability of the information
contained herein and/or for the fitness for any particular use and/or for the performance of any material and/
or equipment selected in whole or part with the user of/or in reliance upon information contained herein.
Selection of materials and/or equipment is at the sole risk of the user of this publication.
This document contains proprietary information of Elsag Bailey, Elsag Bailey Process Automation, and
is issued in strict confidence. Its use, or reproduction for use, for the reverse engineering, development
or manufacture of hardware or software described herein is prohibited. No part of this document may be
photocopied or reproduced without the prior written consent of Elsag Bailey.

I-E96-315B
Preface
The Hydraulic Servo Slave Module (IMHSS02) is a position con-
trol module. It interfaces a servo valve to the Multi-Function
Processor (IMMFP01/02/03) or Multi-Function Controller
(IMMFC03/04/05). The MFP or MFC controls the position of a
steam or gas turbine throttle valve by sending a position
demand to the HSS. The HSS drives its outputs to open or
close the throttle valve to match the position demand. The MFP
or MFC uses the Frequency Counter Slave (IMFCS01) to mea-
sure the turbine speed. The FCS measures turbine speed by
counting and timing pulses from a magnetic pickup on the tur-
bine shaft. The controller or processor module uses this count
to calculate turbine speed and calculate a new demand based
on a setpoint.
The IMHSS02 is a compatible replacement of the IMHSS01.
This manual provides the user with information and instruc-
tions for installation, operation and troubleshooting of the
HSS. Anyone involved with the installation and operation of the
hydraulic servo slave should carefully read and understand
this manual.
General information about the module and related equipment
is contained herein. This manual is not an application guide.

I-E96-315B
®
List of Effective Pages
Total number of pages in this manual is 61, consisting of the following:
Page No. Change Date
Preface Original
List of Effective Pages Original
iii through vii Original
1-1 through 1-7 Original
2-1 through 2-9 Original
3-1 through 3-8 Original
4-1 through 4-6 Original
5-1 through 5-3 Original
6-1 through 6-9 Original
7-1 through 7-1 Original
8-1 through 8-1 Original
A-1 through A-2 Original
B-1 through B-3 Original
C-1 through C-2 Original
Index-1 through Index-3 Original
NOTE: On an updated page, the changed text or table is indicated by a vertical bar in the outer mar-
gin of the page at the changed area. A changed figure is indicated by a vertical bar in the outer mar-
gin next to the figure caption. The date the update was prepared will appear beside the page
number.

vi I-E96-315B
Safety Summary
®
GENERAL
WARNINGS Equipment Environment
All components whether in transportation, operation, or storage
must be in a noncorrosive environment.
Electrical Shock Hazard During Maintenance
Disconnect power or take precautions to ensure that contact with
energized parts is avoided when servicing.
Special Handling
This module uses Electrostatic Sensitive Devices (ESD).
SPECIFIC
CAUTIONS Only qualified personnel should install the throttle valve, hydraulic
actuator, servo valve and linear variable differential transformer.
Improper installation can cause damage to plant equipment, reduce
plant performance and compromise the safety of plant personnel
(p.3-2).
Only qualified personnel should configure these switches. Damage
or misoperation could occur if switches are improperly configured
(p.3-3).

I-E96-315B vii
Sommaire de Sécurité
AVERTISSEMENTS
D’ORDRE
GÉNÉRAL
Environment de l'equipment
Ne pas soumettre les composants a une atmosphere corrosive lors
du transport, de l'entreposage ou de l'utilisation.
Risques de chocs electriques lor de l'entretien
S'assurer de debrancher l'alimentaion ou de prendre les precau-
tions necessaires a eviter tout conatact avec des composants sours
tension lors de l'entretien.
Precautions de Manutention
Ce module contient des composantes sensibles aux decharges
electro-statiques.
ATTENTIONS
D’ORDRE
SPÉCIFIQUE
Seul le personnel qualifie doit installer la soupape modulatrice,
l'actioneur hydraulique, la soupape de pilotage et le transformateur
lineaire a differentiel variable. Une installation inadequate pourrait
endommager l'equipment en chantier, reduire les performances de
l'usine et mettre en jeu la securite du personnel (p.3-2).
La configuration de ces interrupteurs ne devait etre effectuee qlue
par un personnel qualifie. Des dommages ou une mauvaise opera-
tion pourraient resulter d'une mauvaise configuration des
interrupteurs (p. 3-3).

Table of Contents
Page
I-E96-315B iii
SECTION 1 - INTRODUCTION....................................................................................................1-1
INTRODUCTION...........................................................................................................1-1
INTENDED USER.........................................................................................................1-1
HARDWARE DESCRIPTION..........................................................................................1-1
HARDWARE APPLICATION...........................................................................................1-1
INSTRUCTION CONTENT .............................................................................................1-2
HOW TO USE...............................................................................................................1-3
NOMENCLATURE ........................................................................................................1-4
GLOSSARY OF TERMS AND ABBREVIATIONS .............................................................1-4
REFERENCE DOCUMENTS..........................................................................................1-6
SPECIFICATIONS.........................................................................................................1-6
SECTION 2 - DESCRIPTION AND OPERATION........................................................................2-1
INTRODUCTION...........................................................................................................2-1
CONTROL LOOP OPERATION.......................................................................................2-1
Hydraulic Servo Slave ............................................................................................2-1
Frequency Counter Slave .......................................................................................2-2
Multi-Function Processor .......................................................................................2-3
HSS MODULE OPERATION ..........................................................................................2-3
HSS MODULE CIRCUITRY ...........................................................................................2-4
SLAVE EXPANDER BUS INTERFACE ...........................................................................2-5
STATUS AND DATA BUFFERS .....................................................................................2-6
MICROCONTROLLER...................................................................................................2-6
POSITION DEMAND AND OUTPUT ...............................................................................2-6
Digital-to-Analog Converter ....................................................................................2-7
Position Error ........................................................................................................2-7
Servo Amplifier ......................................................................................................2-7
Dither Oscillator ....................................................................................................2-7
POSITION FEEDBACK..................................................................................................2-7
Demodulator..........................................................................................................2-7
Sample Hold Circuit...............................................................................................2-8
Analog-to-Digital Converter ....................................................................................2-8
LVDT OSCILLATOR ......................................................................................................2-8
DIGITAL I/O ................................................................................................................2-9
SECTION 3 - INSTALLATION.....................................................................................................3-1
INTRODUCTION...........................................................................................................3-1
HANDLING...................................................................................................................3-1
Special Handling....................................................................................................3-1
General Handling...................................................................................................3-1
INSTALLING THE PROCESS HARDWARE .....................................................................3-2
INSTALLING THE TERMINATION UNIT OR MODULE....................................................3-2
Termination Unit Installation .................................................................................3-2
Termination Module Installation ............................................................................3-3
INITIAL SWITCH SETTINGS .........................................................................................3-3
Switch S1 - Slave Expander Bus Address ...............................................................3-3
Switch S2 - Controller Gain ...................................................................................3-4
Switch S3 - Dither Oscillator Frequency .................................................................3-5
Switch S4 - Dither Oscillator Current Amplitude ....................................................3-6
Switch S5 - LVDT Primary Voltage Amplitude ........................................................3-6

iv I-E96-315B
Table of Contents (continued)
Page
®
SECTION 3 - INSTALLATION
(continued)
Switch S6 - Demodulator Gain .............................................................................. 3-7
Switch S7 - LVDT Oscillator Frequency.................................................................. 3-7
SLAVE MODULE INSTALLATION ................................................................................. 3-7
CONFIGURATION ........................................................................................................ 3-8
SECTION 4 - CALIBRATION.......................................................................................................4-1
INTRODUCTION .......................................................................................................... 4-1
INITIAL CALIBRATION ................................................................................................. 4-1
CONTROLLER TUNING................................................................................................ 4-3
Analog Control Tuning Theory ............................................................................... 4-3
Tuning the Controller Gain .................................................................................... 4-4
ON-LINE CALIBRATION ............................................................................................... 4-5
SECTION 5 - OPERATING PROCEDURES................................................................................5-1
INTRODUCTION .......................................................................................................... 5-1
FACEPLATE INDICATORS............................................................................................ 5-1
START-UP AND NORMAL OPERATION ......................................................................... 5-1
MANUAL OPERATION.................................................................................................. 5-2
Emergency Manual Mode....................................................................................... 5-2
Emergency Trip ..................................................................................................... 5-3
SECTION 6 - TROUBLESHOOTING...........................................................................................6-1
INTRODUCTION .......................................................................................................... 6-1
HOW TO USE THIS SECTION ...................................................................................... 6-1
OFF-LINE FAILURE ..................................................................................................... 6-1
ON-LINE FAILURE ....................................................................................................... 6-2
Module Failure ...................................................................................................... 6-3
Restoring Operation............................................................................................... 6-7
SECTION 7 - MAINTENANCE.....................................................................................................7-1
INTRODUCTION .......................................................................................................... 7-1
MAINTENANCE............................................................................................................ 7-1
REPAIR/REPLACEMENT PROCEDURES...................................................................... 7-1
SECTION 8 - SUPPORT SERVICES...........................................................................................8-1
INTRODUCTION .......................................................................................................... 8-1
REPLACEMENT PARTS AND ORDERING INFORMATION ............................................. 8-1
TRAINING.................................................................................................................... 8-1
TECHNICAL DOCUMENTATION................................................................................... 8-1
APPENDIX A - QUICK REFERENCE MATERIAL.....................................................................A-1
INTRODUCTION ..........................................................................................................A-1
APPENDIX B - DIGITAL I/O TERMINATION UNIT (NTDI01)....................................................B-1
INTRODUCTION ..........................................................................................................B-1
APPENDIX C - DIGITAL INPUT TERMINATION MODULE (NIDI01)........................................C-1
INTRODUCTION ........................................................................................................C-16

List of Figures
No. Title Page
I-E96-315B v
1-1. The HSS within the INFI 90 Hierarchy ....................................................................1-2
2-1. Turbine Speed Control Loop...................................................................................2-2
2-2. HSS Functional Block Diagram ..............................................................................2-4
2-3. Position Demand and Output Circuit .....................................................................2-6
2-4. Position Feedback Circuit ......................................................................................2-8
2-5. Typical Digital Input Circuit ...................................................................................2-9
3-1. Switch Locations on the HSS .................................................................................3-4
5-1. Faceplate Indicators...............................................................................................5-2
6-1. Off-Line Failure Troubleshooting Flowchar .............................................................6-2
6-2. On-Line Failure Troubleshooting Flowchart............................................................6-8
B-1. NTDI01 Dipshunt and Connector Locations .......................................................... B-1
B-2. NTDI01 Terminal Block Assignments for I/O Signals ............................................. B-3
B-3. HSS to NTDI01 Termination Cable Connection ...................................................... B-3
C-1. HSS Jumper Settings and Location on the NIDI01 ................................................ C-1
C-2. I/O Signal Terminal Assignments for the HSS ....................................................... C-2
C-3. HSS to NIDI01 Termination Cable Connection....................................................... C-2
List of Tables
No. Title Page
3-1. Slave Expander Bus Address - Example Settings ....................................................3-4
3-2. S2 Controller Gain .................................................................................................3-5
3-3. S3 Dither Oscillator Frequencies............................................................................3-5
3-4. S4 Dither Oscillator Amplitude...............................................................................3-6
3-5. S5 LVDT Excitation Voltage ...................................................................................3-6
3-6. S6 Demodulator Gains...........................................................................................3-7
3-7. S7 LVDT Oscillator Frequency................................................................................3-8
4-1. Controller Tuning Log ............................................................................................4-6
5-1. LED States.............................................................................................................5-1
6-1. Troubleshooting On-Line Failures ..........................................................................6-5
6-2. Module Failure Indicators ......................................................................................6-7
6-3. Troubleshooting On-Line Failures ..........................................................................6-9
7-1. Maintenance Schedule ...........................................................................................7-1
A-1. Edge Connector P1 (Module Power) Pin Assignments ............................................. A-1
A-2. Edge Connector P2 (Slave Expander Bus) Pin Assignments ................................... A-1
A-3. Edge Connector P3 (Process Interface) Pin Assignments ........................................ A-1
B-1. NTDI01 Dipshunt Configuration for the HSS ......................................................... B-2

INTRODUCTION
I-E96-315B 1 - 1
SECTION 1 - INTRODUCTION
INTRODUCTION
The Hydraulic Servo Slave (IMHSS02) is a position control
module. It provides an interface through which a controller or
processor module can control a hydraulic actuator via a servo
valve. By regulating the current to the servo valve, it initiates a
change in actuator position. A linear variable differential trans-
former (LVDT) provides actuator position feedback to the HSS.
Typical uses for the HSS are positioning of steam turbine throt-
tle and control valves, gas turbine fuel valves, inlet guide vanes
and nozzle angle.
INTENDED USER
Anyone who installs, operates and maintains the HSS should
read and understand this manual before placing it into service.
Installation requires a technician or engineer with analog con-
trol tuning experience. Operation requires an individual who
knows turbine start-up and plant operating procedures.
HARDWARE DESCRIPTION
The HSS is an intelligent module, with on-board microproces-
sor, memory and communication circuitry. The module con-
sists of a printed circuit card attached to a faceplate. Two
status LEDs are visible through the faceplate. The HSS occu-
pies one slot in a module mounting unit (MMU).
HARDWARE APPLICATION
The HSS module interfaces a controller or processor module to
a servo valve, providing control (manual or automatic) of a
hydraulic actuator. The hydraulic actuator positions a gas tur-
bine fuel valve or steam governor valve. As the fuel or steam
valve opens or closes, it regulates fuel or steam flow to the tur-
bine thus controlling the turbine speed. Figure 1-1 shows an
example of the HSS within the INFI 90 ®hierarchy.
In most applications, the HSS works with the frequency
counter slave (FCS) through a multi-function processor (MFP).
The FCS counts and times pulse inputs from a magnetic sens-
ing device on the turbine shaft. The MFP uses the data from
the FCS to calculate turbine speed. The configuration within
the MFP uses the calculated speed to drive the servo valve out-
puts according to the control strategy of the user.
® INFI 90 is a registered trademark of the Bailey Controls Company.

INTRODUCTION
INSTRUCTION CONTENT
1 - 2 I-E96-315B
®
INSTRUCTION CONTENT
This manual is divided into eight sections. Read this document
before installing or operating the HSS. A summary of section
content follows:
Introduction Introduction contains general information and technical
specifications.
Description and
Operation This section uses block diagrams, schematics and text to
explain module operation.
Figure 1-1. The HSS within the INFI 90 Hierarchy
INFI-NET
CONTROLWAY
SLAVE EXPANDER BUS
HSS
CONTROL
FCS
TURBINE
SPEED
I/O
FIELD I/O
MFP POSITION
DEMAND
NIS NPM
OIS
LEGEND:
FCS = FREQUENCY COUNTER SLAVE
HSS = HYDRAULIC SERVO SLAVE
MFP = MULTI-FUNCTION PROCESSOR
NIS = NETWORK INTERFACE SLAVE
NPM = NETWORK PROCESSOR MODULE
OIS = OPERATOR INTERFACE STATION
TP50202A

INTRODUCTION
HOW TO USE
I-E96-315B 1 - 3
Installation Installation covers the preliminary steps to prepare the module
for operation. It covers switch settings, configuration and field
wiring.
Calibration The calibration section explains how to calibrate the module
with the LVDT and tune the control loop before placing it into
operation.
Operating Procedures The operation section provides information on daily use,
start-up procedures and normal operation.
Troubleshooting This section explains LED conditions, lists status messages
and shows corrective action when problems occur.
Maintenance The maintenance section contains a table of scheduled mainte-
nance procedures.
Support Services This section explains the services and training that Bailey Con-
trols makes available to their customers.
Appendices There are three appendices that provide a quick reference of
HSS module edge connector pin assignments, and explain how
to configure the NTDI01 Termination Unit and NIDI01 Termi-
nation Module.
HOW TO USE
Read this manual before handling the HSS. Refer to a specific
section for information as needed.
1. Read Section 5 before installing the HSS.
2. Read and do the steps in Section 3.
3. Read and do the steps in Section 4.
4. Refer to Section 6 for what to do if a problem occurs.
5. Refer to Section 7 for scheduled maintenance require-
ments.
6. Use Section 8 for a replacement parts list and warranty
information.
7. Refer to the appendices for a quick reference of termination
unit or module installation information.

INTRODUCTION
NOMENCLATURE
1 - 4 I-E96-315B
®
NOMENCLATURE
GLOSSARY OF TERMS AND ABBREVIATIONS
Hardware Nomenclature
IEMMU01/02/04 Module Mounting Unit
IMFCS01 Frequency Counter Slave Module
IMMFP01/02/03
IMMFC03/04/05 Multi-Function Processor Module Multi-Function Controller Module
NIDI01
NTDI01 Digital Input Termination Module Digital Input Termination Unit
NKTM01,
NKTU02/12
NKTU01/12
Termination Cable, NIDI01 to IMHSS02
Termination Cable, NTDI01 to IMHSS02
Term Definition
ADC Analog-to-Digital Converter.
A/D Conversion Analog-to-Digital Conversion. Process of generating a digital representation
of the magnitude of an analog signal.
Controlway A high speed, redundant, peer-to-peer communication link. Used to transfer
information between intelligent modules within a process control unit.
CTM Configuration and Tuning Module. Provides a local means for system config-
uration, tuning and monitoring of intelligent masters over module bus.
CTT Configuration and Tuning Terminal. A handheld module with the same func-
tionally as the configuration and tuning module.
DAC Digital-to-Analog Converter.
D/A Conversion Digital-to-Analog Conversion. Process of generating an analog signal of a
magnitude that corresponds to a digital value.
Dipshunt A dual in-line package with shorting bars.
Dipswitch A dual in-line package that contains switches.
ESD Electrostatic Sensitive Devices. Electronic components subject to damage
or failure when exposed to an electrostatic charge; require special handling.
FCS Frequency Counter Slave.
FTP Field Termination Panel. A panel inside the INFI 90 cabinet that provides a
place to mount termination units.

INTRODUCTION
GLOSSARY OF TERMS AND ABBREVIATIONS (continued)
I-E96-315B 1 - 5
GLOSSARY OF TERMS AND ABBREVIATIONS
(continued)
® Network 90 is a registered trademark of the Bailey Controls Company.
Term Definition
Function Code An algorithm which manipulates specific functions. These functions are
linked together to form the control strategy.
Hydraulic Actuator A cylinder that converts hydraulic power into mechanical work (opening or
closing a valve).
LVDT Linear Variable Differential Transformer. A transformer that provides actua-
tor position feedback by inducing a differential voltage proportional to the
core position (hydraulic actuator position), when driven by an excitation volt-
age.
MCU Microcontroller. A self-contained microprocessor with on-board memory, I/O
ports and support circuitry.
MFC Multi-Function Controller Module. A multiple loop controller with data acqui-
sition and information processing capabilities.
MFP Multi-Function Processor Module. A multiple loop controller with data acqui-
sition and information processing capabilities.
Module Bus Peer-to-peer communication link used to transfer information between intelli-
gent modules within a process control unit.
MMU Module Mounting Unit. A card cage that provides electrical and communica-
tion support for INFI 90/Network 90®modules.
OIS Operator Interface Station. Integrated operator console with data acquisition
and reporting capabilities. It provides a digital access into the process for
flexible control and monitoring.
Servo Valve,
Hydraulic A valve, driven by a calibrated electrical signal, that loads or unloads hydrau- lic fluid to one side of a double acting hydraulic actuator.
Slave Expander
Bus Parallel communication bus between the master and slave modules.
TMU Termination Mounting Unit. A card cage that provides housing for termina-
tion modules and cables.
TM Termination Module. Provides input/output connection between plant equip-
ment and the INFI 90/Network 90 modules.
TU Termination Unit. Provides input/output connection between plant equip-
ment and the INFI 90/Network 90 modules.

INTRODUCTION
REFERENCE DOCUMENTS
1 - 6 I-E96-315B
®
REFERENCE DOCUMENTS
SPECIFICATIONS
Number Document
I-E92-501-2 Configuration/Tuning Terminal (CTT02)
I-E93-903 Configuration/Tuning Module (NCTM01)
I-E96-100 Operator Interface Station (IIOIS20)
Operation/Configuration
I-E96-200 Function Code Application Manual
I-E96-201 Multi-Function Processor Module (IMMFP01)
I-E96-202 Multi-Function Processor Module (IMMFP02)
I-E96-203 Multi-Function Processor Module (IMMFP03)
I-E96-211 Multi-Function Controller Module (IMMFC03)
I-E96-212 Multi-Function Controller Module (IMMFC04)
I-E96-213 Multi-Function Controller Module (IMMFC05)
I-E96-314 Frequency Counter Slave Module (IMFCS01)
I-E96-410 Digital Input Termination Module (NIDI01)
I-E96-424 Digital Input Termination Unit (NTDI01)
TP89-2 Analog Control Techniques and Tuning
GENERAL
Microprocessor
Process I/O
Digital I/O
System Communication
8 bit processor running at 4 MHz
2 analog inputs - LVDT secondary inputs 1 and 2. 3 analog outputs
- servo drive outputs 1 and 2, LVDT primary drive.
3 inputs - raise, lower, trip bias
1 output - emergency manual
8 bit parallel through the slave expander bus.
POWER REQUIREMENTS
Operating
Consumption
Surge Protection
+5 VDC @ 160 mA typical
+15 VDC @ 70 mA typical
-15 VDC @ 60 mA typical
+24 VDC @ 15 mA typical
5 VDC - 0.80 watts
+15 VDC - 1.05 watts
-15 VDC - 0.90 watts
+24 VDC - 0.36 watts
Meets IEEE-472-1974 Surge Withstand Capability Test.

INTRODUCTION
SPECIFICATIONS (continued)
I-E96-315B 1 - 7
SPECIFICATIONS
(continued)
OPERATING
LVDT Supply Primary
Excitation Output
LVDT Secondary Two
Position Inputs
Output to Servo Valve
Coils
Servo Output Protection
Digital Output
Digital Inputs
1 kHz, 2.5 kHz or 10 kHz (selectable), 4 to 12 volts peak-to-peak
adjustable in steps. Minimum LVDT primary impedance 500 ohms.
30 volts peak-to-peak, ±10 VDC common mode, 20k ohms (differ-
ential input) impedance
Two redundant analog outputs at ±0.024 amps each. Minimum coil
impedance 80 ohms each.
Current limiting resistor allows shorting or opening one output with-
out impairing control from the other output.
Independent, optically isolated, open collector outputs.
On: Vout = 2.4 VDC maximum
Iout = 250 mA maximum
Off: Vout = 24 VDC nominal
Iout = 10 uA maximum
Three, optically isolated, contact inputs.
On: Vin = 10 VDC minimum
Iin = 4.5 mA forward current typical at Vin =24VDC
Off: Vin = 2 VDC maximum turn-off voltage
Iin = 10 uA maximum leakage current
ENVIRONMENTAL
Electromagnetic/Radio
Frequency Interference
Ambient Temperature
Atmospheric Pressure
Humidity
Air Quality
Values are not available at this time. Keep cabinet doors closed. Do
not use communication equipment any closer than two meters from
the cabinet.
0° to 70°C (32°to 158°F)
Sea level to 3 km (1.86 miles)
5% to 90% RH (±5%) up to 55°C (noncondensing)
5% to 40% RH (+5%) at 70°C (noncondensing)
Noncorrosive
MOUNTING The HSS occupies one slot in the INFI 90 module mounting unit
(MMU).
CERTIFICATION CSA certified for use as process control equipment in an ordinary
(nonhazardous) location.
Specifications subject to change without notice.

INTRODUCTION
I-E96-315B 2 - 1
SECTION 2 - DESCRIPTION AND OPERATION
INTRODUCTION
This section explains the operation of the hydraulic servo slave
(HSS). It gives an overview of the slave and related modules
within a process control system and explains the operation of
key module circuitry.
CONTROL LOOP OPERATION
The hydraulic servo slave, frequency counter slave (FCS) and
multi-function processor (MFP) form the controlling segment of
a closed loop control system. The MFP is the master module
and directs the control process. The HSS and FCS are slave
modules that interface the process to the MFP. Figure 2-1
shows a diagram of the turbine speed control loop and the con-
trol signals to and from the process.
Hydraulic Servo Slave
The HSS provides control of throttle valve position in a turbine
speed control system. The MFP sends data to the hydraulic
servo slave, which directs the control of a hydraulic actuator
(via a servo valve). By sending a position demand to the HSS,
the MFP initiates a change in turbine speed. The position
demand travels over the slave expander bus to the HSS. An
on-board microcontroller reads the demand and loads it into a
digital-to-analog converter (DAC). The resulting analog value
drives the servo valve. The servo valve loads hydraulic fluid to
one side of a double acting hydraulic actuator. As the hydrau-
lic actuator opens or closes the throttle valve, the turbine
speed changes.
For the MFP to work with the HSS, it requires function code
150 in its configuration. Function code 150 defines the slave
address, mode of operation (calibration or normal), calibration
cycle time and stores calibration data. The twelve output
blocks include actuator position, LVDT null position and sta-
tus outputs for the module and process equipment.
A linear variable differential transformer measures actuator
position. The HSS supplies either a 1000, 2500 or 10,000 hertz
excitation voltage (switch selectable) to the primary side of the
LVDT. The secondary of the LVDT develops a differential volt-
age proportional to the position of the hydraulic actuator. The
HSS converts the differential voltage to digital data and sends
it to the MFP. Using the data the MFP stores (during valve cali-
bration) in its configuration specifications (S8-S9), it translates
the LVDT secondary differential voltage into actuator position

DESCRIPTION AND OPERATION
CONTROL LOOP OPERATION
2 - 2 I-E96-315B
®
feedback. The HSS is self checking and notifies the MFP if a
failure occurs.
The operator can initiate manual control of the turbine throttle
valve if a HSS communication failure with the MFP occurs. The
HSS provides inputs that the user hard wires to a +24 VDC
source. The user directs the HSS to raise or lower the actuator
through external inputs (pushbuttons, contacts, etc.). Also, a
trip bias circuit on the HSS drives the fuel throttle valve to the
closed position in an emergency.
Frequency Counter Slave
The FCS detects turbine speed by counting pulses it receives
from a magnetic pickup on the turbine shaft. Additionally, it
keeps a 24 bit timer value corresponding to the period of the
pulse count. It stores these values in a buffer and sets a data
available status bit to notify the MFP that it has current data.
FCS operation is automatic. It continuously updates the count
and holds it for the MFP.
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

DESCRIPTION AND OPERATION
HSS MODULE OPERATION
I-E96-315B 2 - 3
For the MFP to work with the FCS, it requires function code
145 in its configuration. Function code 145 defines the slave
address, high/low speed alarms and high/low rate of change
alarms. The block output is frequency of input pulses in hertz.
The frequency counter slave continuously checks itself and
notifies the MFP if a failure occurs.
Multi-Function Processor
The MFP is the master module of the control loop and controls
turbine speed according to the users control strategy. The MFP
requests data from the FCS to calculate turbine speed. If the
FCS has data available, it sends it to the MFP. If there is no
data available the MFP must make another request. If the tur-
bine speed goes above or below the speed set point in the MFP
configuration, the MFP will send a position demand to the HSS
to adjust the throttle valve. This process repeats continuously
at the cycle time of the MFP.
The user sets the turbine speed limits and high/low speed
alarms during configuration of the MFP and slave modules.
Additionally, the user calibrates the hydraulic actuator and
LVDT. The MFP sends data, module status and alarms to the
operator interface during normal operation. The operator can
monitor system operation and initiate automatic or manual
control through the operator interface.
HSS MODULE OPERATION
The HSS interfaces the MFP to a servo valve, providing the MFP
with position control of a fuel throttle valve or steam governor
valve. The HSS microcontroller carries the workload. It is able
to perform multiple tasks with the help of the module support
circuitry. The microcontroller provides the intelligence (firm-
ware) needed to relay position demands from the MFP, read
position feedback information, set targets for the output,
present module status information to the MFP, direct manual
control and do self check diagnostics. There are seven func-
tional blocks (see Figure 2-2).
Slave Expander Bus Interface (XBUS I/O)
Status and Data Buffers
Microcontroller (MCU)
Position Demand and Output
Position Feedback Input
LVDT Oscillator
Digital I/O

DESCRIPTION AND OPERATION
HSS MODULE CIRCUITRY
2 - 4 I-E96-315B
®
All the blocks of the support circuitry help the MCU direct
module activity and interface the control loop. Power enters the
board by way of the module mounting unit backplane. The
slave expander bus interface provides slave communication
with the processor module. The position demand circuitry per-
forms digital-to-analog conversion of position demands, while
the output circuitry amplifies the current driving the servo
valve coils. A dither oscillator prevents fuel valves from freezing
in one position. The position feedback block demodulates feed-
back from the LVDT secondary and converts it from an analog
signal to digital data. A frequency selectable (1, 2.5 or 10 kilo-
hertz) oscillator supplies the excitation voltage for the LVDT
primary. The digital I/O circuitry provides isolated DC inputs
that allows the operator to control the actuator position when a
module communication failure interrupts automatic control.
HSS MODULE CIRCUITRY
The following text explains the operation of the seven func-
tional blocks that make up the hydraulic servo slave module.
Figure 2-2. HSS Functional Block Diagram
MICRO-
CONTROLLER
STATUS AND
DATA STORAGE
XBUS
I/O
RAISE/LOWER
CONTACT INPUTS
DIGITAL I/O
POSITION FEEDBACK
POSITION DEMAND
DIGITAL I/O
LVDT OSCILLATOR
ISOLATION/
DEBOUNCE
DEMODULATOR
SAMPLE/HOLD
A/D CONVERTER
D/A CONVERTER
POSITION ERROR
AMPLIFICATION
DITHER OSCILLATOR
ISOLATION/
DEBOUNCE
EMERGENCY
MANUAL OUTPUT
LVDT
SECONDARIES
TRIP BIAS
CONTACT INPUT
LVDT
PRIMARY
OUTPUTS TO
SERVO VALVE
COILS
TP25014B
SLAVE EXPANDER BUS