Watlow CLS200 Operating Manual

CLS200
User’s Guide

CLS200 Series User’s Guide

Safety Warnings, Cautions, and Notes

WARNING! The controller may fail in a 0% or 100% power

output state. To prevent death, personal injury, equipment
damage or property damage, install external safety shutdown
devices. If death or injury may occur, you must install approved
safety shutdown devices that operate independently from the
process control equipment.

WARNING! Risk of electric shock. Shut off power to your entire
process before you begin installation of the controller.

WARNING! To reduce the risk of fire or electric shock, install
the CLS200 in a controlled environment, relatively free of
contaminants.

WARNING! To reduce the risk of electrical shock, fire, and
equipment damage, follow all local and national electrical codes.
Correct wire sizes, fuses and thermal breakers are essential for
safe operation of this equipment.

WARNING! Use a power supply with a Class 2 rating only. UL®
approval requires a Class 2 power supply.

WARNING! During autotuning, the controller will set the output
to 100% until the process variable rises near the setpoint. Set
the setpoint within the safe operating limits of your system.

WARNING! Do not rely solely on the output override feature to
shut down your process. Install external safety devices or over­temperature devices for emergency shutdowns.

WARNING! Do not rely solely on the sensor fail alarm to adjust
the output in the event of a sensor failure. If the loop is in manual
control when a failed sensor alarm occurs, the output is not
adjusted. Install independent external safety devices that will
shut down the system if a failure occurs.

CAUTION! Never run input leads in bundles with high power
wires or near other sources of EMI. This could inductively couple
voltage onto the input leads and damage the controller or could
induce noise and cause poor measurement and control.

Physically separate high-voltage circuits from low-voltage circuits
and from CLS200 hardware. If possible, install high-voltage ac
power circuits in a separate panel.

CAUTION! Without proper grounding, the CLS200 may not
operate properly or may be damaged.

CAUTION! To prevent damage from incorrect connections, do
not turn on the ac power before testing the connections.

CAUTION! The EPROM and other components are sensitive
to damage from electrostatic discharge (ESD). To prevent ESD
damage, use an ESD wrist strap or another antistatic device.

NOTE! For indoor use only.

Avertissements, Attentions et Remarques

AVERTISSEMENT! Le régulateur peut s’avérer défaillant avec

un régime de puissance de sortie à 0 % ou à 100 %. Pour éviter
tout risque de décès, blessure personnelle, endommagements
de l’équipement ou dégâts matériels, veuillez installer des
équipements d’arrêt d’urgence externes. Si un décès ou
un accident venait à se produire, vous devez installer des
équipements d’arrêt d’urgence approuvés qui fonctionnent
indépendamment du matériel de contrôle du processus.

AVERTISSEMENT! Risques de choc électrique. Coupez le
courant de votre processus tout entier avant de commencer à
installer le régulateur.

AVERTISSEMENT! Afin de minimiser les risques d’incendie ou
de choc électrique, installez le CLS200 dans un environnement
sous contrôle et relativement épargné par les contaminants.

AVERTISSEMENT! Afin de minimiser les risques de choc
électrique, d’incendie, et de dégâts matériels, suivez tous les
codes de l’électricité locaux et nationaux. Des diamètres de fils,
des fusibles et des disjoncteurs magnéto-thermiques adaptés
sont indispensables pour un fonctionnement sécurisé de cet
équipement.

AVERTISSEMENT! Utilisez uniquement une alimentation
électrique avec une note de rang 2. Une approbation UL®
impose une alimentation électrique de rang 2.

AVERTISSEMENT! Pendant le réglage automatique, le
régulateur définira la sortie sur 100 % jusqu’à ce que la variable
du processus s’élève près de la valeur seuil. Définissez la valeur
seuil dans les limites de fonctionnement sécurisées de votre
système.

AVERTISSEMENT! Ne comptez pas uniquement sur la fonction
de priorité de sortie pour arrêter le processus. Installez les
dispositifs de sécurité externes ou de protection contre l’excès
de température pour les arrêts d’urgence.

AVERTISSEMENT! Ne comptez pas uniquement sur l’alarme
d’échec du capteur pour ajuster la sortie dans l’éventualité
d’une défaillance du capteur. Si la boucle est en contrôle manuel
lorsqu’une alarme d’échec du capteur se déclenche, la sortie
n’est pas ajustée. Installez des dispositifs externes indépendants
qui éteindront le système si une défaillance se produit.

ATTENTION! Ne faites jamais fonctionner des conducteurs
d’entrée en faisceau avec des câbles à haute puissance ou
près d’autres sources d’EMI. Cela pourrait lier par couplage
inductif la tension sur les conducteurs d’entrée et endommager
le régulateur, ou créer un bruit et être à l’origine de mauvaises
mesures et de régulations erronées.

Séparez physiquement les circuits haute-tension des circuits
basse-tension et du matériel CLS200. Si possible, installez des
circuits électriques ca haute-tension dans un panneau séparé.

2

CLS200 Series User’s Guide

ATTENTION! Sans mise à la terre appropriée, il se peut que le
CLS200 ne fonctionne pas correctement ou soit endommagé.

ATTENTION! Pour éviter tout dommage causé par des
connexions incorrectes, n’allumez pas l’alimentation électrique
en ca avant d’avoir testé les connexions.

ATTENTION! L’EPROM et les autres composants sont sensibles
aux dégâts provoqués par les décharges électrostatiques (ESD).
Pour éviter de tels dommages, utilisez un bracelet antistatique
ou tout autre dispositif antistatique.

REMARQUE : Destiné à un usage intérieur uniquement.

Technical Assistance

If you encounter a problem with your Watlow® controller, review
your configuration information to verify that your selections are
consistent with your application: inputs, outputs, alarms, limits, etc.
If the problem persists, you can get technical assistance from your
local Watlow representative (see back cover), by e-mailing your
questions to [e-mail] or by dialing +1 (507)
494-5656 between 7 a.m. and 5 p.m. Central Time USA & Canada.
Ask for for an Applications Engineer. Please have the complete
model number available when calling.

Return Material Authorization (RMA)

1. Call Watlow Customer Service, [phone], for a Return
Material Authorization (RMA) number before returning any
failed product to Watlow. If you do not know why the product
failed, contact an Application Engineer. All RMA’s require:

• Ship-to address

• Bill-to address

• Contact name

• Phone number

• Method of return shipment

• Your P.O. number

• Detailed description of the problem

• Any special instructions

• Name and phone number of person returning the
product

2. Prior approval and an RMA number from the customer
service department is required when returning any product.
Make sure the RMA number is on the outside of the
carton and on all paperwork returned. Ship on a freight
prepaid basis.

3. After we receive your return, we will examine it to verify the
reason for the product failure. Unless otherwise agreed to
in writing, Watlow’s standard warranty provisions, which can
be located at www.watlow.com/terms, will apply to any failed
product.

4. In the event that the product is not subject to an applicable
warranty, we will quote repair costs to you and request a
purchase order from you prior to proceeding with the
repair work.

5. Watlow reserves the right to charge for no trouble found
(NTF) returns.

Contact Watlow

1241 Bundy Boulevard
Winona, Minnesota 55987 USA
Phone: [phone]
Fax: [phone]

http://www.watlow.com

Warranty

This product is warranted by Watlow for a period of 36 months in
accordance with the terms and conditions set forth on Watlow’s
website, which may be accessed at www.watlow.com/terms.

Document

Document Number: 10-30466 Revision –
August 2019

©2019 Watlow Electric Manufacturing Company, all rights reserved. Watlow® is a registered trademark of Watlow Electric and Manufacturing
Company. Modbus® is a registered trademark of Schneider Automation Incorporated. UL® is a registered trademark of Underwriter’s
Laboratories, Inc. Windows® is a registered trademark of Microsoft Corporation.

3

Table of Contents

Chapter 1: System Overview—12

Manual Contents 12
Getting Started 13

Safety Symbols 13
Initial Inspection 13

Product Features 13
CLS200 Parts List 15

CLS200 16
TB50 17
CLS200 Cabling 18
External Safety Devices 18
Power-Fail Protection 18

Chapter 2: Installation—19

Typical Installation 19
Mounting Controller Components 20

Recommended Tools 20
Mounting the Controller 21
Mounting the TB50 23
Mounting the Power Supply 25

System Wiring 25

Wiring Recommendations 26
Noise Suppression 26
Ground Loops 28

Power Connections 29

Wiring the Power Supply 29
Connecting TB50 to CLS200 31

Testing Your System 31

TB50 or TB18 Test 31
Digital Output Test 31
Digital Input Test 31

Sensor Wiring 32

Input Wiring Recommendations 33
Thermocouple Connections 33
RTD Input Connections 34
Reference Voltage Terminals 34
Voltage Input Connections 34
Current Input Connections 35
Pulse Input Connections 35

Wiring Control and Digital I/O 36

Output Wiring Recommendations 36
Cable Tie Wraps 37
Digital Outputs 37
Digital Inputs 40

TB18 Connections 41
TB50 Connections 42

Analog Outputs 44

Wiring the Dual DAC 44
Wiring the Serial DAC 44

Serial Communications 44

EIA/TIA-232 Interface 44
EIA/TIA-485 Interface 46
EIA/TIA-485 Converters and Laptop
Computers 47

Chapter 3: Using CLS200—48

Front Panel 49

Front Panel Keys 49

Displays 51

Bar Graph Display 51
Single Loop Display 52
Alarm Displays 53
System Alarms 55

Job Display 55
Changing the Setpoint 56
Selecting the Control Status 56

Manual and Automatic Control 57
Autotuning a Loop 57

Using Alarms 59

Alarm Delay 59
Failed Sensor Alarms 59
Process Alarms 61
Global Alarm 63

Ramp/Soak 63

Chapter 4: Setup—64

How to Access the Setup Menus 64

How to Change a Parameter 64

Standard Menus 66
Setup Global Parameters Menu 67

Load Setup From Job 67
Save Setup to Job 68
Job Select Digital Inputs 68
Job Select Digital Inputs Active 69
Output Override Digital Input 70
Override Digital Input Active 70
Startup Alarm Delay 70
Keyboard Lock Status 71

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CLS200 Series User’s Guide

Power Up Output Status 71
Process Power Digital Input 71
Controller Address 72
Communications Baud Rate 72
Communications Protocol 72
Communications Error Checking 72
AC Line Frequency 73
Digital Output Polarity on Alarm 73
EPROM Information 73

Setup Loop Input Menu 74

Input Type 75
Loop Name 76
Input Units 76
Input Reading Offset 76
Reversed T/C Detection 77
Input Pulse Sample Time 77
Linear Scaling Parameters 77
Input Filter 80

Setup Loop Control Parameters Menu 81

Heat or Cool Control PB 82
Heat or Cool Control TI 82
Heat or Cool Control TD 82
Heat or Cool Output Filter 83
Spread 83
Restore PID Digital Input 83

Setup Loop Outputs Menu 84

Enable or Disable Heat or Cool Outputs 85
Heat or Cool Output Type 85
Heat or Cool Cycle Time 86
SDAC Mode 86
SDAC Low Value 86
SDAC High Value 86
Heat or Cool Output Action 87
Heat or Cool Output Limit 87
Heat or Cool Output Limit Time 87
Sensor Fail Heat or Cool Output 88
Heat or Cool Thermocouple Break Output
Average 88
Heat or Cool Linearity 88

Setup Loop Alarms Menu 89

High Process Alarm Setpoint 90
High Process Alarm Type 90
High Process Alarm Output Number 90
Deviation Alarm Value 91
High Deviation Alarm Type 91
High Deviation Alarm Output Number 91
Low Deviation Alarm Type 91
Low Deviation Alarm Output Number 92
Low Process Alarm Setpoint 92
Low Process Alarm Type 92
Low Process Alarm Output Number 92
Alarm Deadband 92
Alarm Delay 93

Manual I/O Test 93

Digital Inputs 94
Test Digital Output 94

Digital Output Number 94
Keypad Test 95
Display Test 95

Chapter 5: Enhanced Features—96

Enhanced Features Menus 97
Process Variable Retransmit 98

Process Variable Retransmit Menu 98
Process Variable Retransmit Example: Data
Logging 100

Cascade Control 102

Setup Loop Cascade Menu 103
Cascade Control Example: Water Tank 105

Ratio Control 108

Setup Loop Ratio Control Menu 108
Ratio Control Example: Diluting KOH 110

Remote Analog Setpoint 112

Remote Analog Setpoint Example: Setting a
Setpoint with a PLC 112

Differential Control 113

Differential Control Example:
Thermoforming 113

Chapter 6: Ramp/Soak—115

Features 116
Ramp/Soak Menus 117
Setup Global Parameters Menu 118

Ramp/Soak Time Base 118

Setup Ramp/Soak Profile Menu 118

Edit Ramp/Soak Profile 118
Copy Setup From Profile 118
Tolerance Alarm Time 119
Ready Segment Setpoint 119
Ready Segment Edit Events 119
External Reset Input Number 120
Edit Segment Number 120
Segment Time 120
Segment Setpoint 121
Edit Segment Events 121
Edit Segment Triggers 122
Segment Tolerance 123
Last Segment 124
Repeat Cycles 124
Setpoints and Tolerances for Various Input
Types 124

Using Ramp/Soak 125

Ramp/Soak Displays 125
Assigning a Profile to a Loop 127
Running a Profile 128
Holding a Profile or Continuing from Hold 128
Responding to a Tolerance Alarm 129
Resetting a Profile 130
In Case of a Power Failure 130

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CLS200 Series User’s Guide

Chapter 7: Turning and Control—131

Control Algorithms 131

On/Off Control 131
Proportional Control 132
Proportional and Integral Control 133
Proportional, Integral and Derivative
Control 133
Heat and Cool Outputs 134

Control Outputs 134

Output Control Signals 134
Output Filter 135
Reverse and Direct Action 135

Setting Up and Tuning PID Loops 136

Proportional Band (PB) Settings 136
Integral Settings 136
Derivative Settings 137

General PID Constants by Application 138

Proportional Band Only (P) 138
Proportional with Integral (PI) 138
PI with Derivative (PID) 138

Chapter 8: Troubleshooting and
Reconfiguring—139

When There is a Problem 139
Troubleshooting Controllers 140

Process and Deviation Alarms 140
Failed Sensor Alarms 141
System Alarms 142
Other Behaviors 142

Corrective and Diagnostic Procedures 143

Low Power 143
Battery Dead 143
Ambient Warning 144
H/W Ambient Failure 144
H/W Gain or Offset Failure 145
Keys Do Not Respond 145
Checking Analog Inputs 145
Earth Grounding 146
Checking Control Outputs 147
Testing Control Output Devices 147
Testing the TB18 and TB50 147
Testing Control and Digital Outputs 147
Testing Digital Inputs 148

Additional Troubleshooting for Computer
Supervised Systems 148

Computer Problems 148
Communications 149
Ground Loops 149
Software Problems 149

NO-Key Reset 150
Replacing the EPROM 150
Removing or Replacing the Battery 152
Changing Communications 153
Scaling Resistors 154

Four-Loop and Eight-Loop Input Circuit 154
Current Inputs to Four-Loop and Eight-Loop

Controllers 155
Voltage Inputs to Four-Loop and Eight-Loop
Controllers 155
RTDs and Thermistor Inputs to Four-Loop and
Eight-Loop Controllers 156
Sixteen-Loop Input Circuit 157
Current Inputs to Sixteen-Loop Controllers 157
Voltage Inputs to Sixteen-Loop Controllers 158
Scaling and Calibration 158

Chapter 9: Linear Scaling Examples—159

Example 1: A 4-to-20mA Sensor 159

Situation 159
Setup 159

Example 2: A 0-to-5VDC Sensor 160

Situation 160
Setup 160

Example 3: A Pulse Encoder 161

Situation 161
Setup 161

Chapter 10: Specifications—162

CLS200 System Specifications 162

CLS200 Processor Physical Specifications 162
TB50 Physical Specifications 164
Inputs 166
Outputs 168

Glossary—171

Index—180

Menu Structure—192

Declaration of Conformity—193

How to Reach Us—194

6

List of Figures

Chapter 1: System Overview—12

Figure 1.1 — CLS200 Rear Views 16
Figure 1.2 — CLS200 Front Panel 17
Figure 1.3 — TB50 17

Chapter 2: Installation—19

Figure 2.1 — CLS200 System Components 20
Figure 2.2 —Clearance with TB18 Option 21
Figure 2.3 —Clearance with Standard SCSI Cable 21
Figure 2.3a — Clearance with Right-Angle SCSI Cable 22
Figure 2.4 —Mounting Bracket Clearance 22
Figure 2.5 —Panel Thickness and Cutout Size 22
Figure 2.6 — Mounting the TB50 23
Figure 2.7 — TB50 Mounted on a DIN Rail (Front) 24
Figure 2.8 — TB50 Mounted on DIN Rail (Side) 24
Figure 2.9 — Mounting a TB50 with Standoffs 25
Figure 2.10 — CLS200 Series Controller with TB18 29
Figure 2.11 — CLS200 Series Controller with TB50 29
Figure 2.12 — Power Connections 30
Figure 2.13 — Thermocouple Connections 33
Figure 2.14 — RTD Connections 34
Figure 2.15 — Linear Voltage Signal Connections 35
Figure 2.16 — Linear Current Signal Connections 35
Figure 2.17 — Encoder with 5VDC TTL Signa 36
Figure 2.18 — Encoder Input with Voltage Divider 36
Figure 2.19 — Digital Output Wiring 38
Figure 2.20 — S ample Heat, Cool and Alarm Output Connections 39
Figure 2.21 — Output Connections Using External Power Supply 39
Figure 2.22 — TB50 Watchdog Timer Output 39
Figure 2.23 — TB18 Watchdog Timer Output 40
Figure 2.24 — Wiring Digital Inputs 41
Figure 2.25 — Connecting One CLS200 to a Computer Using EIA/TIA-232 45
Figure 2.26 — EIA/TIA-485 Wiring 46
Figure 2.27 — Recommended System Connections 47

Chapter 3: Using CLS200—48

Figure 3.1 — Operator Displays 48
Figure 3.2 — CLS200 Front Panel 49
Figure 3.3 — Bar Graph Display 51
Figure 3.4 — Single Loop Display 52
Figure 3.5 — Single Loop Display, Heat and Cool Outputs Enabled 53
Figure 3.6 — Single Loop Display with a Process Alarm 53

7

CLS200 Series User’s Guide

Figure 3.7 — Failed Sensor Alarm in the Single Loop Display 54
Figure 3.8 — Alarm Symbols in the Bar Graph Display 54
Figure 3.9 — Activation and Deactivation of Process Alarms 62

Chapter 4: Setup—64

Figure 4.1 — CLS200 Menu Tree 66
Figure 4.2 — Two Points Determine Process Variable Conversion 78
Figure 4.3 — Process Variable Limited by Input Reading Range 78
Figure 4.4 — Linear and Nonlinear Outputs 89
Figure 4.5 — Digital Inputs Screen 94

Chapter 5: Enhanced Features—96

Figure 5.1 — Enhanced Features Option Menus 97
Figure 5.2 — Linear Scaling of Process Variable for Retransmit 100
Figure 5.3 — Application Using Process Variable Retransmit 101
Figure 5.4 — Relationship Between the Primary Loop’s Output and the Secondary Loop’s Setpoint 103
Figure 5.5 — Application Using Cascade Control 105
Figure 5.6 — Secondary Loop Setpoint Related to Primary Loop Output 107
Figure 5.7 — Relationship Between the Master Loop’s Process Variable and the Ratio Loop’s Setpoint 108
Figure 5.8 — Application Using Ratio Control 110

Chapter 6: Ramp/Soak—115

Figure 6.1 — Sample Ramp/Soak Profile 115
Figure 6.2 — Setup Ramp/Soak Profiles Menu 117
Figure 6.3 — Positive and Negative Tolerances 123
Figure 6.4 — Ramp/Soak Screens 125

Chapter 7: Turning and Control—131

Figure 7.1 — On/Off Control 132
Figure 7.2 — Proportional Control 132
Figure 7.3 — Proportional and Integral Control 133
Figure 7.4 — Proportional, Integral and Derivative Control 133
Figure 7.5 — Time Proportioning and Distributed Zero Crossing Waveforms 134

Chapter 8: Troubleshooting and Reconfiguring—139

Figure 8.1 — Remove Board Assembly from Case 151
Figure 8.2 — Disconnect Keypad Ribbon Cable from Processor Board 151
Figure 8.3 — Unlatch Boards from Carrier 151
Figure 8.4 — Remove the Standoffs 151
Figure 8.5 — EPROM Location 152
Figure 8.6 — Remove EPROM 152
Figure 8.7 — Battery-Backed RAM Module on the Processor Board 153
Figure 8.8 — Jumper Configurations 153
Figure 8.9 — Differential Input Circuit in Four-Loop and Eight-Loop Controllers 154
Figure 8.10 — Single-Ended Input Circuit in Sixteen-Loop Controllers 157

Chapter 10: Specifications—162

Figure 10.1 — CLS200 Processor Module Dimensions 163
Figure 10.2 — CLS200 Clearances with Straight SCSI Cable 163
Figure 10.3 — CLS200 Clearances with Right-Angle SCSI Cable 164
Figure 10.4 — TB50 Dimensions 165
Figure 10.5 — TB50 Dimensions with Standard SCSI Cable 165
Figure 10.6 — TB50 Dimensions with Right-Angle SCSI Cable 166

8

List of Tables

Chapter 1: System Overview—12

Table 1.1 — Ordering Options 15

Chapter 2: Installation—19

Table 2.1 — Cable Recommendations 26
Table 2.2 — Power Connections 29
Table 2.3 — Analog Input Connections on TB1 for Four-Loop and Eight-Loop Models 32
Table 2.4 — Analog Input Connections on TB1 for Sixteen-Loop Models 32
Table 2.5 — Digital Output States and Values Stored in the Controller 37
Table 2.6 — Digital Inputs States and Values Stored in the Controller 40
Table 2.7 — TB18 Connections 41
Table 2.8 — TB50 Connections for Four-Loop and Eight-Loop Controllers 42
Table 2.9 — TB50 Connections for Sixteen-Loop Controllers 43
Table 2.10 — EIA/TIA-232 Connections 45
Table 2.11 — RTS/CTS Pins in DB-9 and DB-25 Connectors 45

Chapter 3: Using CLS200—48

Table 3.1 — Bar Graph Display Symbols 51
Table 3.2 — Control Status Symbols on the Bar Graph and Single Loop Displays 52
Table 3.3 — Alarm Type and Symbols 54

Chapter 4: Setup—64

Table 4.1 — Global Parameters 67
Table 4.2 — Job Select Inputs 69
Table 4.3 — Job Selected for Various Input States 69
Table 4.4 — Firmware Option Codes 74
Table 4.5 — Setup Loop Input 74
Table 4.6 — CLS200 Input Types and Ranges 75
Table 4.7 — Input Character Sets 76
Table 4.8 — Input Reading Offset 77
Table 4.9 — Display Formats 79
Table 4.10 — Setup Loop Control Parameters 81
Table 4.11 — Setup Loop Outputs 84
Table 4.12 — Heat / Cool Output Types 85
Table 4.13 — Setup Loop Alarms 90
Table 4.14 — Manual I/O Test 93

Chapter 5: Enhanced Features—96

Table 5.1 — Application Example: Setting Up Process Variable Retransmit 101
Table 5.2 — Application Example: Setting Up Cascade Control 106
Table 5.3 — Application Example: Setting Up Ratio Control 111

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CLS200 Series User’s Guide

Table 5.4 — Application Example: Setting Up Remote Setpoint 112
Table 5.5 — Application Example: Setting Up Differential Control 114

Chapter 6: Ramp/Soak—115

Table 6.1 — Ramp/Soak Specifications 116
Table 6.2 — Trigger Latch Logic 123
Table 6.3 — Display Formats 124
Table 6.4 — Ramp/Soak Single Loop Display 125
Table 6.5 — Ramp/Soak Control Status Symbols 126
Table 6.6 — Ramp/Soak Profile Modes 129

Chapter 7: Turning and Control—131

Table 7.1 — Proportional Band Settings 136
Table 7.2 — Integral Term and Reset Settings 137
Table 7.3 — Derivative Term Versus Rate 137
Table 7.4 — General PID Constants 138

Chapter 8: Troubleshooting and Reconfiguring—139

Table 8.1 — Controller Alarm Codes for Process and Deviation Alarms 140
Table 8.2 — Operator Response to Alarms 141
Table 8.3 — Failed Sensor Alarm Codes 141
Table 8.4 — Hardware Error Messages 142
Table 8.5 — Other Symptoms 142
Table 8.6 — Resistor Values for Current Inputs to Four-Loop and Eight-Loop Controllers 155
Table 8.7 — Resistor Locations for Current Inputs to Four-Loop and Eight-Loop Controllers 155
Table 8.8 — Resistor Values for Voltage Inputs to Four-Loop and Eight-Loop Controllers 155
Table 8.9 — Resistor Locations for Voltage Inputs to Four-Loop and Eight-Loop Controllers 156
Table 8.10 — Resistor Values for RTD and Thermistor Inputs to Four-Loop and Eight-Loop Controllers 156
Table 8.11 — Resistor Locations for RTD and Thermistor Inputs to Four-Loop and Eight-Loop Controllers 156
Table 8.12 — Resistor Values for Current Inputs to Sixteen-Loop Controllers 157
Table 8.13 — Resistor Locations for Current Inputs to Sixteen-Loop Controllers 157
Table 8.14 — Resistor Values for Voltage Inputs to Sixteen-Loop Controllers 158
Table 8.15 — Resistor Locations for Voltage Inputs to Sixteen-Loop Controllers 158

Chapter 9: Linear Scaling Examples—159

Table 9.1 — Input Readings 159
Table 9.2 — Scaling Values 159
Table 9.3 — Input Readings and Calculations 160
Table 9.4 — Scaling Values 160
Table 9.5 — Scaling Values 161

Chapter 10: Specifications—162

Table 10.1 — Agency Approvals / Compliance 162
Table 10.2 — Environmental Specifications 162
Table 10.3 — Physical Dimensions 162
Table 10.4 — Processor with Standard SCSI Cable 163
Table 10.5 — Processor with Right Angle SCSI Cable 163
Table 10.6 — Processor Connections 164
Table 10.7 — TB50 Physical Dimensions 164
Table 10.8 — TB50 Connections 165
Table 10.9 — TB50 with Straight SCSI Cable 165
Table 10.10 — TB50 with Right Angle SCSI Cable 166
Table 10.11 — Analog Inputs 166

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CLS200 Series User’s Guide

Table 10.12 — Pulse Inputs 167
Table 10.13 — Thermocouple Range and Resolution 167
Table 10.14 — RTD Range and Resolution 168
Table 10.15 — Input Resistance for Voltage Inputs 168
Table 10.16 — Digital Inputs 168
Table 10.17 — Digital Outputs Control / Alarm 169
Table 10.18 — CPU Watchdog Output 169
Table 10.19 — 5VDC Output (Power to Operate Solid-State Relays) 169
Table 10.20 — Reference Voltage Output (Power to Operate Bridge Circuit Sensors) 170
Table 10.21 —Serial Communication 170
Table 10.22 — Power Requirements 170

11

Chapter 1: System Overview

Manual Contents

This manual describes how to install, set up, and operate CLS200 controllers. Each chapter covers
a different aspect of your control system and may apply to different users:

• Chapter 1: System Overview provides a component list and summary of features for the
CLS200 series controllers.

• Chapter 2: Installation provides detailed instructions on installing the CLS200 series
controller and its peripherals.

• Chapter 3: Using CLS200 provides an overview of operator displays used for system
monitoring and job selection.

• Chapter 4: Setup provides detailed descriptions of all menus and parameters for controller
setup.

• Chapter 5: Enhanced Features describes process variable retransmit, ratio, differential and
cascade control features available with the enhanced features option.

• Chapter 6: Ramp/Soak explains how to set up and use the features of the ramp/soak
option.

• Chapter 7: Turning and Control describes available control algorithms and provides
suggestions for applications.

• Chapter 8: Troubleshooting and Reconfiguring includes troubleshooting, upgrading and
reconfiguring procedures for technical personnel.

• Chapter 9: Linear Scaling Examples provides an example configuring a pressure sensor, a
flow sensor, and an encoder using linear scaling.

• Chapter 10: Specifications lists detailed specifications of the controller and optional
components.

12

CLS200 Series User’s Guide

Chapter 1: System Overview

Getting Started

The following sections provide information regarding product features, technical descriptions, safety
requirements, and preparation for operation.

Safety Symbols

These symbols are used throughout this manual:

NOTE! Marks a short message to alert you to an important detail.

CAUTION! Information that is important for protecting your equipment and

performance. Be especially careful to read and follow all cautions that apply to your
application.

WARNING! Safety alert appears with information that is important for protecting you,
others and equipment from damage. Pay very close attention to all warnings that apply
to your application.

Initial Inspection

Accessories may or may not be shipped in the same container as the CLS200, depending upon
their size. Check the shipping invoice carefully against the contents received in all boxes.

Product Features

The CLS200 series controllers provide 4, 8 or 16 fully independent control loops. When used as
a stand-alone controller, you may operate the CLS200 via the two-line 16-character display and
touch keypad. You can also use it as the key element in a computer-supervised data acquisition and
control system; the CLS200 can be locally or remotely controlled via an EIA/TIA-232 or EIA/TIA-485
serial communications interface.

The CLS200 features include:

• Direct Connection of Mixed Thermocouple Sensors: Connect most thermocouples
to the controller with no hardware modifications. Thermocouple inputs feature reference
junction compensation, linearization, process variable offset calibration to correct for sensor
inaccuracies, detection of broken, shorted or reversed thermocouples, and a choice of
Fahrenheit or Celsius display.

• Accepts Resistive Temperature Detectors (RTDs): Use 3-wire, 100Ω, platinum,

0.00385-curve sensors with two choices for range and precision of measurements. (To use
this input, order a four-loop or eight-loop controller with scaling resistors.)

• Automatic Scaling for Linear Analog Inputs: The CLS200 series automatically scales
linear inputs used with industrial process sensors. Enter two points, and all input values are
automatically scaled in your units. Scaling resistors must be installed.

• Dual Outputs: The CLS200 series includes both heat and cool control outputs for each
loop. Independent control parameters are provided for each output.

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CLS200 Series User’s Guide

Chapter 1: System Overview

• Independently Selectable Control and Output Modes: You can set each control output
to on/off, time proportioning, Serial DAC (digital-to-analog converter), or distributed zero
crossing mode. Set up to two outputs per loop for on/off, P, PI or PID control with reverse or
direct action.

• Control Outputs: Set high/low deviation and high/ low process limits to operate digital
outputs as on/off control functions or alarms.

• Flexible Alarm Outputs: Independently set high/ low process alarms and a high/low
deviation band alarm for each loop. Alarms can activate a digital output by themselves, or
they can be grouped with other alarms to activate an output.

• Global Alarm Output: When any alarm is triggered, the global alarm output is also triggered,
and it stays on until you acknowledge it.

• CPU Watchdog: The CLS200 series CPU watchdog timer output notifies you of system
failure. Use it to hold a relay closed while the controller is running, so you are notified if the
microprocessor shuts down.

• Front Panel or Computer Operation: Set up and run the controller from the front panel or
from a local or remote computer. Watlow® offers SpecView, a Windows® compatible Human
Machine Interface (HMI) software package that includes data logging and graphing features in
addition to process monitoring.

• Modbus® RTU Protocol, EIA/TIA-232 and 485 Communications: Connect to PLCs,
operator interface terminals and third-party software packages using the widely supported
Modbus® RTU protocol.

• Multiple Job Storage: Store up to eight jobs in memory, and access them locally by
entering a single job number or remotely via digital inputs. Each job is a set of operating
conditions, including setpoints and alarms.

• Nonlinear Output Curves: Select either of two non-linear output curves for each control
output.

• Autotuning: Use the autotune feature to set up your system quickly and easily.

• Pulse Counter Input: Use the pulse counter input for precise control of motor or belt speed.

• Low Power Shutdown: The controller shuts down and turns off all outputs when it detects
the input voltage drop below the minimum safe operating level.

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CLS200 Series User’s Guide

Chapter 1: System Overview

CLS200 Parts List

You may have received one or more of the following components. See Table 1.1 – Ordering Options
for configuration information.

• CLS200 series controller

• Controller mounting kit

• TB50 with 50-pin SCSI cable

• EIA/TIA-232 or EIA/TIA-485 communications cable

• Special input resistors (installed in CLS200)

Table 1.1 — Ordering Options

CHARACTERISTIC OPTIONS DESCRIPTION

4 Loops

Number of Loops

Firmware

Digital I/O Termination

Digital I/O Termination
Board Accessory

Digital I/O Termination
Cable Accessory

Serial Communication
Jumper Settings

Serial Communication
Cable

Mounting Hardware

Customer Specific None Not applicable to standard product

8 Loops

16 Loops

Standard

Ramp and Soak

Enhanced Features

Screw Terminals (TB18) TB18 Terminal Block

Mass Termination (SCSI) SCSI Connector

None No external terminal board included

TB50 Terminal Board TB50-SCSI (50 Pin terminal board)

None

3-foot SCSI cable

6-foot SCSI cable

3-foot SCSI cable with right angle
connector

EIA/TIA-232

EIA/TIA-485, not terminated

EIA/TIA-485, terminated

None No communication cable

10 foot communication cable
(DB-9 female/bare wires)

Plastic collar and screw clips Standard mounting hardware

Low profile metal L-brackets and
screws

The number of analog inputs and control
loops that can be controlled based on the
feedback from the analog inputs. There is an
additional control loop that uses feedback
from the pulse input.

Includes closed-loop, PID control, auto­tune, alarms, job memory and failed sensor
detection

Provides the features of the standard version
plus the additional Ramp and Soak features

Provides the features of the standard version
plus the additional Enhanced Features

Accessory cable to connect digital I/O
signals between the SCSI connector on the
controller and the TB50 board

Application uses 232 communication or no
communication

Application uses 485 communication, this
controller is not last in the network

Application uses 485 communication, this
controller is last in the network

Cable for 232 communication

Mounting hardware for legacy applications
with tight fit

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CLS200 Series User’s Guide

Chapter 1: System Overview

CHARACTERISTIC OPTIONS DESCRIPTION

Analog Input 1 Options for all units:

Analog Input 2

Analog Input 3

Analog Input 4

Analog Input 5

Analog Input 6

Analog Input 7

Analog Input 8

Analog Input 9

Analog Input 10

Analog Input 11

Analog Input 12

Analog Input 13

Analog Input 14

Analog Input 15

Analog Input 16

• Standard (Thermocouples and

-10 to 60mV)

• Linear Current: 0-20mA DC /
4-20mA DC

• Linear Voltage: 0-5VDC

• Linear Voltage: 0-10VDC

Additional options for 4-loop and
8-loop units:

• 100 Ohm RTD Tenths Degree

• 100 Ohm RTD Whole Degree

Standard units accept thermocouples on
all inputs. Controllers can be equipped with
resistors to scale signals for various types
of sensors. These resistors must be factory
installed.

Sixteen loop controllers cannot accept RTD
sensors.

Technical Description

This section contains a technical description of each component of your CLS200 series controller.

CLS200

The CLS200 is housed in an 1/8-DIN panel mount package. It contains the CPU, RAM with a built-in
battery, EPROM, serial communications, digital I/O, analog inputs, the screen and touch keypad.

SCSI Digital I/O Option TB18 Digital I/O Option

Figure 1.1 — CLS200 Rear Views

The CLS200 has the following features:

• Keypad and 2-line, 16-character display.

• Screw terminals for the power and analog inputs and communications.

• Input power is 12 to 24VDC at 1 Amp.

• A 50-pin SCSI cable connects the digital inputs and outputs to the 50-terminal block (TB50).
Four-loop and eight-loop models are available with an 18-terminal block (TB18) in place of the
SCSI connector, as shown in Figure 1.2.

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CLS200 Series User’s Guide

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The firmware resides in an EPROM. See Replacing the EPROM on page 150 for information on
removing and replacing the EPROM.

The operating parameters are stored in battery-backed RAM. If there is a power loss the operating
parameters are unchanged. The battery has a ten-year shelf life, and it is not used when the unit
is on.

The microprocessor performs all calculations for input signal linearization, PID control, alarms and
communications.

Front Panel Description

The display and touch keypad provide an intelligent way to operate the controller. The display has
16 alphanumeric or graphic characters per line. The 8-key keypad allows you to change the
operating parameters, controller functions, and displays.

The information-packed displays show process variables, setpoints, and output levels for each loop.
A bar graph display, single loop display, scanning display and an alarm display offer a real-time view
of process conditions. Two access levels allow operator changes and supervisor changes.

1.98 in.

(50 mm)

3.80 in.
(96 mm)

Figure 1.2 — CLS200 Front Panel

TB50

The TB50 is an optional screw-terminal interface for control wiring which allows you to connect
relays, encoders and discrete I/O devices to the CLS200. The screw terminal blocks accept wires as
large as 18 AWG (0.75 mm2). A 50-pin SCSI cable connects the TB50 to the CLS200.

Figure 1.3 — TB50

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CLS200 Series User’s Guide

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CLS200 Cabling

Watlow offers optional cables to support installing your CLS200. A 50-pin SCSI cable connects the
TB50 to the CLS200.

The optional cable used to connect the CLS200 to a computer using EIA/TIA-232 communications
has a DB9 connector for the computer and bare wires for connecting to the CLS200.

Safety

Watlow has made every effort to ensure the reliability and safety of this product. In addition, we have
provided recommendations that will allow you to safely install and maintain this controller.

External Safety Devices

The CLS200 controller may fail full-on (100% output power) or full-off (0% output power), or may
remain full-on if an undetected sensor failure occurs. For more information about failed sensor
alarms, see Failed Sensor Alarms on page 59.

Design your system to be safe even if the controller sends a 0% or 100% output power signal at any
time. Install independent, external safety devices that will shut down the system if a failure occurs.

Typically, a shutdown device consists of an agency approved high/low process limit controller
that operates a shutdown device such as a mechanical contactor. The limit controller monitors
for a hazardous condition such as an undertemperature or over-temperature fault. If a hazardous
condition is detected, the limit controller sends a signal to open the contactor.

The safety shutdown device (limit controller and contactor) must be independent from the process
control equipment.

WARNING! The controller may fail in a 0% or 100% power output state. To prevent
death, personal injury, equipment damage or property damage, install external safety
shutdown devices. If death or injury may occur, you must install approved safety
shutdown devices that operate independently from the process control equipment.

With proper approval and installation, thermal fuses may be used in some processes.

Power-Fail Protection

In the occurrence of a sudden loss of power, this controller can be programmed to reset the control
outputs to off (this is the default). Typically, when power is re-started, the controller restarts to data
stored in memory. If you have programmed the controller to restart with control outputs on, the
memory-based restart might create an unsafe process condition for some installations. Therefore,
you should only set the restart with outputs on if you are certain your system will safely restart. (See
Process Power Digital Input on page 71.)

When using a computer or host device, you can program the software to automatically reload
desired operating constants or process values on power-up. Keep in mind that these convenience
features do not eliminate the need for independent safety devices.

Contact Watlow if you have any questions about system safety or system operation.

18

Chapter 2: Installation

This chapter describes how to install the CLS200 series controller and its peripherals. Installation of
the controller involves the following procedures:

• Determining the best location for the controller

• Mounting the controller and TB50

• Power connection

• Input wiring

• Communications wiring (EIA/TIA-232 or EIA/TIA-485)

• Output wiring

WARNING! Risk of electric shock. Shut off power to your entire process before you
begin installation of the controller.

WARNING! The controller may fail in a 0% or 100% power output state. To prevent
death, personal injury, equipment damage or property damage, install external safety
shutdown devices. If failure may cause death or injury, you must install approved safety
shutdown devices that operate independently from the process control equipment.

Typical Installation

Figure 2.1 shows typical installations of the controller with the TB50 and the TB18 terminal blocks.
The type of terminal block you use greatly impacts the layout and wiring of your installation site. (See
Figures 2.2 to 2.11.)

We recommend that you read this entire chapter first before beginning the installation procedure.
This will help you to carefully plan and assess the installation.

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CLS200 Series User’s Guide

Chapter 2: Installation

CLS200 with SCSI Digital I/O

Sensor Inputs

SCSI Connector

CLS200 with TB18 Digital I/O

Sensor Inputs

TB18 allows connection to...
11 Outputs for Control & Alarms
2 Digital Inputs
1 Pulse Input

Figure 2.1 — CLS200 System Components

TB50 Accessory Board

SCSI Cable

TB50 allows connection to...
35 Outputs for Control & Alarms
8 Digital Inputs
1 Pulse Input

Mounting Controller Components

Install the controller in a location free from excessive heat (below 50ºC [122°F]), dust, and
unauthorized handling. Electromagnetic and radio frequency interference can induce noise on
sensor wiring. Select locations for the CLS200 and TB50 such that wiring can be routed clear of
sources of interference such as high voltage wires, power switching devices and motors.

NOTE! For indoor use only.

WARNING! To reduce the risk of fire or electric shock, install the CLS200 in a controlled

environment, relatively free of contaminants.

Recommended Tools

Use any of the following tools to cut a hole of the appropriate size in the panel.

• Jigsaw and metal file, for stainless steel and heavyweight panel doors.

• 1/8-DIN rectangular punch for most panel materials and thicknesses.

• Nibbler and metal file, for aluminum and lightweight panel doors.

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CLS200 Series User’s Guide

2.44 in.

Chapter 2: Installation

You will also need these tools:

• Phillips head screwdriver

• 1/8 in. (3 mm) flathead screwdriver for wiring

• Multimeter

Mounting the Controller

Mount the controller before you mount the terminal block or do any wiring. The controller’s
placement affects placement and wiring considerations for the other components of your system.

Ensure there is enough clearance for mounting brackets, terminal blocks, and cable and wire
connections.

(62 mm)

1.98 in.
(50 mm)

1.00 in.
(25 mm)

Figure 2.2 —Clearance with TB18 Option

1.98 in.
(50 mm)

1.00 in.

(25 mm)

Figure 2.3 —Clearance with Standard SCSI Cable

8.00 in.

(203 mm)

2.44 in.
(62 mm)

10.00 in.
(254 mm)

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CLS200 Series User’s Guide

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2.44 in.

(62 mm)

1.98 in.
(50 mm)

1.00 in.
(25 mm)

Figure 2.3a — Clearance with Right-Angle SCSI Cable

9.00 in.

(229 mm)

4.02 in.

(102 mm)

Figure 2.4 —Mounting Bracket Clearance

1.80 ± 0.020 in.
(45.7 ± 0.5 mm)

Figure 2.5 —Panel Thickness and Cutout Size

3.63 ± 0.020 in.
(92.2 ± 0.5 mm)

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CLS200 Series User’s Guide

Chapter 2: Installation

We recommend you mount the controller in a panel not more than 0.2 in. (5 mm) thick.

1. Choose a panel location free from excessive heat (below 50°C [122°F]), dust, and unauthorized
handling. (Make sure there is adequate clearance for the mounting hardware, terminal blocks,
and cables. The controller extends 7.00 in. (178 mm) behind the panel. Allow adequate room
for wiring and cables beyond the connectors.)

2. Temporarily cover slots in the metal housing so that dirt, metal filings, and pieces of wire do not
enter the housing and lodge in the electronics.

3. Cut a hole in the panel 1.80 in. (46 mm) by 3.63 in. (92 mm) as shown above. (Use caution; the
dimensions given here have 0.02 in. (0.5 mm) tolerances.

4. Remove the brackets and collar from the controller, if they are already in place.

5. Slide the controller into the panel cutout.

6. Slide the mounting collar over the back of the controller, making sure the mounting screw
indentations face toward the back of the controller.

7. Loosen the mounting bracket screws enough to allow for the mounting collar and panel
thickness. Place each mounting bracket into the mounting slots (head of the screw facing
the back of the controller). Push each bracket backward then to the side to secure it to the
controller’s case.

8. Make sure the controller is seated properly. Tighten the installation screws firmly against the
collar to secure the unit. Ensure that the end of the mounting screws fit into the indentations on
the mounting collar.

Mounting the TB50

There are two ways you can mount the TB50: use the pre-installed DIN rail mounting brackets or
use the plastic standoffs. Follow the corresponding procedure to mount the board.

DIN Rail Mount

Standoffs

Figure 2.6 — Mounting the TB50

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CLS200 Series User’s Guide

Chapter 2: Installation

DIN Rail Mounting

Snap the TB50 on to the DIN rail by placing the hook side on the rail first, then pushing the snap
latch side in place. (See Figure 2.7.)

Figure 2.7 — TB50 Mounted on a DIN Rail (Front)

To remove the TB50 from the rail, use a flathead screwdriver to unsnap the bracket from the rail.
(See Figure 2.8.)

Figure 2.8 — TB50 Mounted on DIN Rail (Side)

Mounting with Standoffs

1. Remove the DIN rail mounting brackets from the TB50.

2. Select a location with enough clearance to remove the TB50, its SCSI cable and the controller
itself.

3. Mark the four mounting holes.

4. Drill and tap four mounting holes for #6 (3.5 mm) screws or bolts.

5. Mount the TB50 with four screws.

There are four smaller holes on the terminal board. Use these holes to secure wiring to the terminal
block with tie wraps.

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CLS200 Series User’s Guide

Chapter 2: Installation

0.2 in.
(5 mm)

3.6 in.

(91 mm)

3.6 in.

(91 mm)

0.7 in.

(18 mm)

Figure 2.9 — Mounting a TB50 with Standoffs

2.6 in.

(66 mm)

0.2 in.
(5 mm)

Mounting the Power Supply

Refer to the power supply manufacturer’s instructions for mounting information. Choose a Class 2
power supply that supplies an isolated regulated 12 to 24VDC at 1A.

Mounting Environment

Leave enough clearance around the power supply so that it can be removed.

System Wiring

Successful installation and operation of the control system can depend on placement of the
components and on selection of the proper cables, sensors, and peripheral components.

Routing and shielding of sensor wires and proper grounding of components can insure a robust
control system. This section includes wiring recommendations, instructions for proper grounding and
noise suppression, and considerations for avoiding ground loops.

WARNING! To reduce the risk of electrical shock, fire, and equipment damage, follow
all local and national electrical codes. Correct wire sizes, fuses and thermal breakers are
essential for safe operation of this equipment.

CAUTION! Do not wire bundles of low-voltage signal and control circuits next to
bundles of high voltage ac wiring. High voltage may be inductively coupled onto the
low-voltage circuits, which may damage the controller or induce noise and cause poor
control.

Physically separate high-voltage circuits from low-voltage circuits and from CLS200
hardware. If possible, install high-voltage ac power circuits in a separate panel.

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CLS200 Series User’s Guide

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Wiring Recommendations

Follow these guidelines for selecting wires and cables:

• Use stranded wire. (Solid wire can be used for fixed service; it makes intermittent connections
when you move it for maintenance.)

• Use 20 AWG (0.5 mm2) thermocouple extension wire. Larger or smaller sizes may be difficult
to install, may break easily, or may cause intermittent connections.

• Use shielded wire. The electrical shield protects the signals and the CLS200 from electrical
noise. Connect one end of the input and output wiring shield to earth ground.

• Use copper wire for all connections other than thermocouple sensor inputs.

Table 2.1 — Cable Recommendations

FUNCTION MFR. P/N NO. OF WIRES AWG MM

Analog Inputs

RTD Inputs

Thermocouple
Inputs

Control Outputs
and Digital I/O

Analog Outputs

Computer
Communication:
EIA/TIA-232, 422
or 485, or 20mA

Belden 9154

Belden 8451

Belden 8772

Belden 9770

T/C Ext. Wire 2 20 0.5

Belden 9539

Belden 9542

Ribbon Cable

Belden 9154

Belden 8451

Belden 9729

Belden 9730

Belden 9842

Belden 9843

Belden 9184

20

50

2

2

3

3

9

2

2

4

6

4

6

4

20

22

20

22

24

24

22 to 14

20

22

24

24

24

24

22

2

0.5

0.5

0.5

0.5

0.2

0.2

0.5 to 2.5

0.5

0.5

0.2

0.2

0.2

0.2

0.5

MAXIMUM LENGTH

4,000 ft. (1,219 m)

4,000 ft. (1,219 m)

6,000 ft. (1,829 m)

Noise Suppression

The CLS200’s outputs are typically used to drive solid state relays. These relays may in turn operate
more inductive types of loads such as electromechanical relays, alarm horns and motor starters.
Such devices may generate electromagnetic interference (EMI or noise). If the controller is placed
close to sources of EMI, it may not function correctly. Below are some tips on how to recognize and
avoid problems with EMI.

For earth ground wire, use a large gauge and keep the length as short as possible. Additional
shielding may be achieved by connecting a chassis ground strap from the panel to CLS200 case.

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CLS200 Series User’s Guide

Chapter 2: Installation

Symptoms of RFI/EMI

If your controller displays the following symptoms, suspect EMI:

• The controller’s display blanks out and then reenergizes as if power had been turned off for
a moment.

• The process variable does not display correctly.

Noise may also damage the digital output circuit—so digital outputs will not turn on. If the digital
output circuit is damaged, return the controller to Watlow for repair.

Avoiding RFI/EMI

To avoid or eliminate most RFI/EMI noise problems:

• Connect the CLS200 case to earth ground. The CLS200 system includes noise suppression
circuitry. This circuitry requires proper grounding.

• Separate the 120 or 240VAC power leads from the low-level input and output leads
connected to the CLS200 series controller. Do not run the digital I/O or control output leads in
bundles with ac wires.

• Where possible, use solid-state relays (SSRs) instead of electromechanical relays. If you must
use electromechanical relays, try to avoid mounting them in the same panel as the CLS200
series equipment.

• If you must use electromechanical relays and you must place them in a panel with CLS200
series equipment, use a 0.01 microfarad capacitor rated at 1000VAC (or higher) in series with
a 47Ω, 0.5 watt resistor across the normally-open contacts of the relay load. This is known as
a snubber network and can reduce the amount of electrical noise.

• You can use other voltage suppression devices, but they are not usually required. For
instance, you can place a metal oxide varistor (MOV) rated at 130VAC for 120VAC control
circuits across the load, which limits the peak ac voltage to about 180VAC. You can also
place a transorb (back-to-back zener diodes) across the digital output, which limits the digital
output voltage.

Additional Recommendations for a Noise Immune System

It is strongly recommended that you:

• Isolate outputs through solid-state relays, where possible.

• Isolate RTDs or “bridge” type inputs from ground.

• Isolate digital inputs from ground through solid state relays. If this is not possible, then make
sure the digital input is the only connection to earth ground other than the chassis ground.

• If you are using EIA/TIA-232 from a non-isolated host, either (1) do not connect any
other power common point to earth ground, or (2) use an optical isolator in the
communications line.

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CLS200 Series User’s Guide

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Ground Loops

Ground loops occur when current passes from the process through the controller to ground. This
can cause instrument errors or malfunctions.

A ground loop may follow one of these paths, among others:

• From one sensor to another.

• From a sensor to the communications port.

• From a sensor to the dc power supply.

The best way to avoid ground loops is to minimize unnecessary connections to ground. Do not
connect any of the following terminals to each other or to earth ground:

• Power supply dc common

• TB1, terminals 5, 6, 11, 12 (analog common)

• TB1, terminal 17 (reference voltage common)

• TB1, terminals 23, 24 (communications common)

• TB2, terminal 2 (dc power common)

Special Precautions for the Sixteen-Loop Models

Sixteen-loop models have single-ended inputs. All the negative sensor leads are tied to the analog
common. That means there is no sensor-to-sensor isolation. Proper grounding is critical for this unit.
Take these additional precautions with a sixteen-loop controller:

• Use all ungrounded or all well-grounded thermocouples, not a mix.

• If using a mixture of thermocouples or low-voltage inputs (<500mV) and current inputs,
connect the negative leads of the current transmitters to terminal 17 (Ref Com) on TB1.

• If using voltage transmitters, use only sourcing models or configuration. Sinking configurations
will not work.

• Isolate the controller’s communication port (if used) by using an optically isolated 232-to-485
converter.

Personal Computers and Ground Loops

Many PC communications ports connect the communications common to chassis ground. When
such a PC is connected to the controller, this can provide a path to ground for current from the
process that can enter the controller through a sensor (such as a thermocouple). This creates a
ground loop that can affect communications and other controller functions. To eliminate a ground
loop, either use an optically isolated communications adapter or take measures to ensure that
sensors and all other connections to the controller are isolated and not conducting current into
the unit.

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CLS200 Series User’s Guide

Chapter 2: Installation

Power Connections

This section covers making the power connections to the CLS200 and connecting the TB50.

TB1

Sensor Inputs

TB2

Power Input

Figure 2.10 — CLS200 Series Controller with TB18

TB2

Power Input

Serial Communication

TB18

Digital Inputs
Digital Outputs
Pulse Input

TB1

Sensor Inputs
Serial Communication

SCSI to TB50

Digital Inputs
Digital Outputs
Pulse Input

Figure 2.11 — CLS200 Series Controller with TB50

Wiring the Power Supply

WARNING! Use a power supply with a Class 2 rating only. UL® approval requires a
Class 2 power supply.

Connect power to the controller before any other connections, This allows you to ensure that the
controller is working before any time is taken installing inputs and outputs.

Table 2.2 — Power Connections

FUNCTION POWER SUPPLY CLS200 TB2

DC Power (Controller) +12 to 24VDC +

DC Common 12 to 24VDC Common –

Earth Ground Ground

1. Connect the dc common terminal on the power supply to the dc common (-) terminal on
CLS200 TB2.

2. Connect the positive terminal on the power supply to the dc positive (+) terminal on
CLS200 TB2.

3. If using an isolated dc output or another power supply to power the loads, connect the dc
common of the supply powering the loads to the dc common of the supply powering the
controller.

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CLS200 Series User’s Guide

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4. Use the ground connector on TB2 for chassis ground. This terminal is connected to the
CLS200 chassis and must be connected to earth ground.

5. Connect 120/240VAC power to the power supply.

NOTE! Connect the dc common of the power supply used for loads to the dc common
of the supply powering the controller. If the supplies are not referenced to one another,
the controller’s outputs will not be able to switch the loads.

NOTE! When making screw terminal connections, tighten to 4.5 to 5.4 inch-pound
(0.5 to 0.6 Nm).

CAUTION! Without proper grounding, the CLS200 may not operate properly or may be
damaged.

CAUTION! To prevent damage from incorrect connections, do not turn on the ac power
before testing the connections as explained in Testing Your System on page 31.

NOTE! Do not connect the controller’s dc common (COM) to earth ground. Doing so will
defeat the noise protection circuitry, making measurements less stable.

Power Supply

+V1 (5V)

0 (5V COM)

+V2 (+15V)

COM (15V COM)

-V2 (-15V)

(Ground)

ACL (AC Line)

ACN (AC Neutral)

white

120/240
VAC
Supply

N

black

H

green

G

* If using 5VDC for outputs, jumper 5V common to 15V common.

** Connect terminals to ac panel ground.

**

Add jumper *

1 2 3 4
+

C

5

O
M

SSR

SSR

Serial DAC

G

C

N

OMV

D

+

CLS200

**

SSR

SSR

Figure 2.12 — Power Connections

30