Tempco TEC-4230, TEC-4220 User Manual

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User's Manual

TEC-4230 Self-Tune Fuzzy/PID Process/Temperature Controller

TEMPCO Electric Heater Corporation 607 N. Central Avenue Wood Dale, IL 60191-1452 USA Tel: 630-350-2252

Revision 6/2003

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Warning Symbol

This symbol calls attention to an operating procedure, practice, or the like which, if not correctly performed or adhered to, could result in personal injury or damage to or destruction of part or all of the product and system. Do not proceed

beyond a warning symbol until the indicated conditions are fully understood and met.

CONTENTS

1. Introduction

2. Numbering System

3. Specifications

4. Installation

5. Operation

6. Recalibration

7. Error Messages and Diagnosis

Information in this user's manual is subject to change without notice.

Copyright © 2003, Tempco Electric Heater Corporation, all rights reserved. No part of this publication may be reproduced, transmitted, transcribed or stored in a retrieval system, or translated into any language in any form by any means without the written permission of Tempco Electric Heater Corporation.

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1. Introduction

TEC-4230 Fuzzy Logic plus PID microprocessor-based controller incorporates a bright, easy to read, 4-digit LED display which indicates the process value. Fuzzy Logic technology enables a process to reach a predetermined set point in the shortest time, with the minimum of overshoot during power-up or external load disturbance. The units are housed in a 1/4 DIN case, measuring 96mm x 96mm with 53mm behind-panel depth. The units feature three touch keys to select the various control and input parameters. Using a unique function, you can determine which parameters are accessible by the user. You can also put up to five parameters at the front of the user menu by using SEL1 to SEL5 found in the setup menu. These are particularly useful to OEM's as it is easy to limit access and configure the menu to suit the specific application.

TEC-4230 is powered by 20–32VAC/VDC or 90–264VAC supply, incorporating a 3 amp control relay output and dual 3 amp alarm relay outputs as standard with a second alarm that can be configured in the second output for cooling purposes or as a dwell timer. Alternative output options include SSR drive, triac, 4–20mA and 0–10 volts. TEC-4230 is fully programmable for PT100, thermocouple types J, K, T, E, B, R, S, N, 0–20mA, 4–20mA, and voltage signal input, with no need to modify the unit.

Digital communications format RS-485 or 4–20mA retransmission are available as an additional option. These options allow the TEC4230 to be integrated with supervisory control systems and software, or alternatively to drive remote displays, chart recorders, or data loggers.

For nearly a hundred years, PID control has been used and has proven to be an efficient controlling method by many industries, yet PID has difficulty dealing with some sophisticated systems such as second and higher order systems, long time-lag systems, during set point changes and/or load disturbances, etc. The PID principle is based on a mathematical model which is obtained by tuning the process. Unfortunately, many systems are too complex to describe precisely in numerical terms. In addition, these systems may vary from time to time. In order to overcome the imperfections of PID control, Fuzzy Technology was introduced. What is Fuzzy Control? It works like a good driver. Under different speeds and circumstances, he can control a car well based on previous experience, and does not require knowledge of the kinetic theory of motion. Fuzzy Logic is a linguistic control which is different from numerical PID control. It controls the system by experience and does not need to simulate the system precisely as a PID controller would.

The function of Fuzzy Logic is to adjust PID parameters internally in order to make manipulation of output value MV more flexible and adaptive to various processes.

The Fuzzy Rule may work like this: If the temperature difference is large, and the temperature rate is large, then ∆MV is large. If the temperature difference is large, and the temperature rate is small, then ∆MV is small.

PID+Fuzzy Control has been proven to be an efficient method to improve control stability as shown by the comparison curves below:

Figure 1.1 Fuzzy PID System Block

Figure 1.2 Fuzzy PID Enhances Control Stability

PID + FUZZY CONTROL

MV PV

PROCESS

PID

FUZZY

Figure 1.1 Fuzzy PID System Block

Digital information

Fuzzy Rule

Language information

Fuzzy Inference Engine

DefuzzifierFuzzifier

Digital information

PID control with properly tuned

PID + Fuzzy control

Temperature

Set point

Warm Up

Load Disturbance

Figure 1.2 Fuzzy PID Enhances Control Stability

Time

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2. Numbering System

TEC-4230-_ _ _ _ _ _ _ _

1 2 3 4 5 6 7 8

(1) Power Input

4 . . . . . . . . 90–264VAC

5 . . . . . . . . 20–32VAC/VDC

9 . . . . . . . . Other

(2) Signal Input (can be programmed in the field)

5 . . . . . . . . TC-Configurable: J, K, T, E, B, R, S, N

6 . . . . . . . . RTD-Configurable: DIN or JIS

7 . . . . . . . . Linear-mV or mA: 4–20, 0–20mA; 0–1, 0–5, 1–5, 0–10VDC

9 . . . . . . . . Other

(3) Range Code

1 . . . . . . . . Field configurable

9 . . . . . . . . Other

(4) Control Mode

3 . . . . . . . . Field configurable

9 . . . . . . . . Other

(5) Output 1

0 . . . . . . . . None

1 . . . . . . . . Relay-3A/240VAC

2 . . . . . . . . Pulse DC for SSR drive-24VDC (20mA max)

3 . . . . . . . . 4–20mA, linear (max. load 500 ohms)

4 . . . . . . . . 0–20mA, linear (max. load 500 ohms)

5 . . . . . . . . 0–10VDC, linear (min. impedance 500K ohms)

6 . . . . . . . . Triac-SSR output 1A/240VAC

9 . . . . . . . . Other

(6) Output 2

0 . . . . . . . . None

1 . . . . . . . . Relay-3A/240VAC

2 . . . . . . . . Pulse DC for SSR drive-24VDC (20mA max)

3 . . . . . . . . 4–20mA, linear (max. load 500 ohms)

4 . . . . . . . . 0–20mA, linear (max. load 500 ohms)

5 . . . . . . . . 0–10VDC, linear (min. impedance 500K ohms)

6 . . . . . . . . Triac-SSR output 1A/240VAC

9 . . . . . . . . Other

(7) Alarm

0 . . . . . . . . None

2 . . . . . . . . Dual relays-2A/240VAC, field configurable (Alarm 2 can be used for output 2/cooling)

9 . . . . . . . . Other

(8) Data Communications

0 . . . . . . . . None

1 . . . . . . . . RS-485

2 . . . . . . . . 4–20mA retransmission

3 . . . . . . . . 0–20mA retransmission

9 . . . . . . . . Other

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3. Specifications

Input

*Accuracy = Linearity Error + Cold Junction Compensating Error + Lead Compensating Error + Offset Drift Error

Linear voltage input impedance: 100K ohms Cold junction compensation: 0.1°F/°F ambient typical Sensor break protection: Configurable by operator External resistance: 100 ohms max. Normal mode rejection: 60dB Common mode rejection: 120dB Sample rate: 5x/second

Control

Proportion band: 0–360°F (0–200°C) Reset (Integral): 0–3600 seconds Rate (Derivative): 0–1000 seconds Ramp rate: 0–99.99°F (0–55.55°C)/minute Dwell: 0–9999 minutes On-off: Adjustable hysteresis 0.1–19.9°F (0–11.0°C) Cycle time: 0–99 seconds Control action: Direct (for cooling) and reverse (for heating)

Power

Rating: 90–264VAC, 50/60Hz Consumption: Less than 5VA

Environmental and Physical

Safety: UL 873, CSA 22.2/142-87, IEC 1010-1 Protection: NEMA 4X, IP65 EMC emission: EN50081-1, EN55011 EMC immunity: IEC801-2, IEC801-3, IEC801-4

Sensor Input Type Range (°F) *Accuracy (°F) Range (°C) *Accuracy (°C)

J Iron/Constantan -58 to 1832°F ±3.6°F -50 to 1000°C ±2°C

K Chromel/Alumel -58 to 2500°F ±3.6°F -50 to 1370°C ±2°C

T Copper/Constantan -454 to 752°F ±3.6°F -270 to 400°C ±2°C

E Chromel/Constantan -58 to 1382°F ±3.6°F -50 to 750°C ±2°C

B Pt30%RH/Pt6%RH 32 to 3272°F ±5.4°F 0 to 1800°C ±3°C

R Pt13%RH/Pt 32 to 3182°F ±3.6°F 0 to 1750°C ±2°C

S Pt10%RH/Pt 32 to 3182°F ±3.6°F 0 to 1750°C ±2°C

N Nicrosil/Nisil -58 to 2372°F ±3.6°F -50 to 1300°C ±2°C

RTD PT 100 ohms (DIN) -328 to 752°F ±0.72°F -200 to 400°C ±0.4°C

RTD PT 100 ohms (JIS) -328 to 752°F ±0.72°F -200 to 400°C ±0.4°C

Linear 4–20mA -1999 to 9999 ±0.05% -1999 to 9999 ±0.05%

Linear 0–20mA -1999 to 9999 ±0.05% -1999 to 9999 ±0.05%

Linear 0–1VDC -1999 to 9999 ±0.05% -1999 to 9999 ±0.05%

Linear 0–5VDC -1999 to 9999 ±0.05% -1999 to 9999 ±0.05%

Linear 1–5VDC -1999 to 9999 ±0.05% -1999 to 9999 ±0.05%

Linear 0–10VDC -1999 to 9999 ±0.05% -1999 to 9999 ±0.05%

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Operating temperature: 14 to 122°F (-10 to 50°C) Humidity: 0 to 90% RH (non-condensing) Insulation: 20M ohms min. (500VDC) Breakdown: 2000V (AC), 50/60Hz, 1 minute Vibration: 10–55 Hz, amplitude 1mm Shock: 200m/s² (20g) Moldings: Flame retardant polycarbonate Dimensions: H: 3.75” (96mm) x W: 3.75” (96mm)

Depth behind panel: 2.07” (53mm)

Weight: 4 oz. (110g)

4. Installation

Dangerous voltage capable of causing death can be present in this instrument. Before installation or beginning any troubleshooting procedures, the power to all equipment must be switched off and isolated. Units suspected of being faulty must be disconnected and removed to a properly equipped workshop for testing and repair. Component replacement and internal adjustments must be made by a qualified maintenance person only.

To minimize the possibility of fire or shock hazards, do not expose this instrument to rain or excessive moisture.

Do not use this instrument in areas under hazardous conditions such as excessive shock, vibration, dirt, moisture, corrosive gases, or oil. The ambient temperature of the areas should not exceed the maximum rating specified.

4–1 Unpacking

Upon receipt of the shipment, remove the unit from the carton and inspect the unit for shipping damage. If there is any damage due to transit, report the damage and file a claim with the carrier. Write down the model number, serial number, and date code for future reference when corresponding with our service center. The serial number (S/N) and date code (D/C) are labeled on the box and the housing of the controller.

4–2 Mounting

Make the panel cutout to fit the dimensions shown in figure 4.1.

Remove both mounting clamps and insert the controller into the panel cutout. Reinstall the mounting clamps. Gently tighten the screws in the clamp until the controller front panel fits snugly in the cutout.

Figure 4.1 Mounting Dimensions

3.6"

(92mm)

Figure .1 Mounting Dimensions

3.6"

(92mm)

Panel cutout

Panel

2.07"

(53 mm)

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4–3 Wiring Precautions

• Before wiring, check the label to verify the correct model number and options. Switch off the power while checking.

• Care must be taken to ensure that the maximum voltage ratings specified in section 3 are not exceeded.

• It is recommended that the power source for these units be protected by fuses or circuit breakers rated at the minimum value possible.

• All units should be installed inside a suitably grounded metal enclosure to prevent live parts from being accessible to human hands and metal tools.

• All wiring must conform to the appropriate standards of good practice and local codes and regulations. Wiring must be suitable for the voltage, current, and temperature ratings of the system.

• The "stripped" leads as specified in figure 4.2 below are used for power and sensor connections.

• Beware not to over-tighten the terminal screws.

• Unused control terminals should not be used as jumper points as they may be internally connected, causing damage to the unit.

• Verify that the ratings of the output devices and the inputs are not exceeded.

• Electrical power in industrial environments contains a certain amount of noise in the form of transient voltage and spikes. This electrical noise can adversely affect the operation of microprocessor-based controls. For this reason we strongly recommend the use of shielded thermocouple extension wire which connects the sensor to the controller. This wire is a twisted-pair construction with foil wrap and drain wire. The drain wire is to be attached to ground at one end only.

4–4 Connection and Wiring

The following connections for outputs and inputs are found on the back of the controller housing.

Figure 4.2 Lead Termination

2.0mm

0.08" max.

Figure .2 Lead Termination

4.5 7.0 mm

0.18" 0.27"

90-264 VAC Power Input

Control Output 1

Control Output 2

Alarm 1

Alarm Com.

Alarm 2

AC1

AC2

N/O

N/C

7 8 9

V-

mA-

+12V

Tx1

Tx2

PTB/COM.

PTB/TC

PTA

11 12 13

VAA

Tx1

Tx2

-VAA

Interface

0-20mA or 4-20mA

RTD

0-10V

Figure 4.3 Rear Terminal Connections

19 20

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Power Wiring

The controller is supplied to operate on 24V (20–32VAC/VDC) or 90–264VAC. Verify that the voltage of the power supply corresponds to that indicated on the product label before connecting power to the controller.

This equipment is designed for installation in an enclosure which provides adequate protection against electrical

shock. The enclosure must be connected to earth ground.

Local requirements regarding electrical installation should be rigidly observed. Consideration should be given to prevent unauthorized personnel from gaining access to the power terminals.

Input Wiring

Connect the appropriate sensor to terminals 11, 12, 17, 18, or 19 as indicated in figure 4.3. Make sure that the correct sensor type is selected on the controller, and that the correct polarity is observed at both ends of the cable. For thermocouple wiring, the correct type of extension wire must be used for the entire distance between the controller and the thermocouple. The extension wires must be the same alloy and polarity as the thermocouple, and joints in the cable should be avoided, if possible. The color codes used on the thermocouple extension wires are shown in table 4.1. For wiring three-wire RTD, the two common wires should be connected to terminals 17 and 18, with the compensating lead connected to terminal 18. When using a two-wire RTD, install a jumper between terminals 17 and 18. A three-wire RTD offers the capability of lead resistance compensation, provided that all three leads are the same gauge and material, and of equal length.

Table 4.1 International Thermocouple Cable Color Codes

* Color of overall sheath

Output Wiring

There are several types of output modules (see section 2) that can be selected for output 1 when ordering the TEC4230, depending on the control application. Make sure the output device you selected is appropriate for your application requirements. The external connections will depend on the type of output installed. If pulsed voltage is selected, note that pulsed voltage output is non-isolated.

Sensor Placement

Proper sensor installation can eliminate many problems in a control system. The probe should be placed so that it can detect any temperature change with minimal thermal lag. In a process that requires fairly constant heat output, the probe should be placed close to the heater. In a process where the heat demand is variable, the probe should be close to the work area. Some experiments with probe location are often required to find the optimum position.

In a liquid process, the addition of a stirrer will help eliminate thermal lag. Since a thermocouple is basically a point measuring device, placing more than one thermocouple in parallel can provide an average temperature readout and produce better results in most air-heated processes.

Thermocouple

Type

Cable

Material

American

ANSI

BritishBSGerman

DIN

French

NFE

J Iron/Constantan

+ white

- red * black

+ yellow

- blue * black

+ red

- blue * blue

+ yellow

- black * black

K Chromel/Alumel

+ yellow

- red * yellow

+ brown

- black * red

+ red

- green * green

+ yellow

- purple * yellow

Copper/ Constantan

+ blue

- red * blue

+ white

- blue * blue

+ red

- brown * brown

+ yellow

- black * black

R S

Platinum/Rhodium

+ black

- red * green

+ white

- blue * green

+ red

- white * white

+ yellow

- green * green

B Platinum/Rhodium

+ grey

- red * grey

+ red

- grey * grey

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The proper sensor type is also a very important factor in obtaining precise measurements. The sensor must have the correct temperature range to meet the process requirements. In special processes, the sensor might have additional requirements such as leak-proof, anti-vibration, antiseptic, etc.

Standard sensor limits of error are ±4°F (±2°C) or 0.75% of sensed temperature (half that for special) plus drift caused by improper protection or an over-temperature occurrence. This error is far greater than controller error and cannot be corrected on the sensor except by proper selection and replacement.

5. Operation

5–1 Front Panel Description

5–2 Keypad Operation

*It takes 12 seconds with power on to memorize the new value of a parameter once it has been changed.

Process Value Display

Control Output 1

Control Output 2

Alarm 1 Output

Alarm 2 Output

Out1

Out2

Alm1

Alm2

TEC-4230

TOUCHKEYS FUNCTION DESCRIPTION

Press and release quickly to select which digit of a numerical parameter to change. Press and hold to increase the value of the selected digit or to change the selection for an index parameter.

Press and release quickly to select which digit of a numerical parameter to change. Press and hold to decrease the value of the selected digit or to change the selection for an index parameter.

Selects the parameter in a direct sequence. Also used to select the tool program parameters.

Selects the parameters in higher security level, and actuates the selected tool program whenever the display is showing a tool program.

Press for at least 3.2 seconds

Up Key

Down Key

(Direct) Scroll Key

Long Scroll/Enter Key

Process Unit Indicator

Set Point Value Display

Keypad

Press

for at least 3.2 seconds

Press

Press for at least 3.2 seconds

Reverse Scroll/Callibration Verification Key

Lock Key

Tool Program Key

Reset/Exit Key

Autotune Key

Selects the parameters in a reverse direction during parameter scrolling, or verifies the display accuracy for various input types during callibration.

Disables keypad operation to protect all the parameters from being tampered with.

Selects the tool programs in sequence.

Unlocks keypad operation and resets the front panel display to normal display mode, exits tool program, or stops the autotuning function.

Starts the autotune program.

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5–3 Menu Overview and Descriptions of Parameters

PROCESS VALUE

SET POINT VALUE

ASP1

RAMP

OFST

Short scroll returns to PV/SV

ASP2

AhY1 AhY2

hYST

Short scroll returns to PV/SV

Exits parameters and returns to PV/SV

NOTE: The display will return to PV/SV in 25 seconds if no entry is made.

ADDR

Short scroll advances forward through parameters step by step

Hold until display stops  flashing (3.2 seconds)

SHIF

Hold until display stops  flashing (3.2 seconds)

LO.SC

hI.SC

PL.1

PL.2 INPT UNIT

RESO

CON.A

A1.MD

A1.SF

A2.MD

A2.SF

CYC

CCYC

C.PB

Short scroll returns to PV/SV

D-B

Short scroll advances forward through parameters step by step

Scrolls through parameters step by step in reverse order

Short scroll advances forward through parameters step by step

Security

Level 0

Security

Level 1

Security

Level 2

Page 11

Parameter descriptions:

Default

Security

Level

Display

Code

Description Adjustment Range

Default Setting

SV Set point value of control Low scale to high scale value 212°F

ASP1

Alarm 1 set point value or Dwell

time

Trip point within high/low scale or

0–9999 minutes (for dwell time)

18°F (10°C)

RAMP

Ramp rate 0–99.99°F/minute (0–55.55°C/minute) 0.00

OFST

Offset value for manual reset 0–100% Only functional if integral (TI) is set to 0. 0.0

ASP2

Alarm 2 set point value Trip point within high/low scale 18°F (10°C)

SHIF

Display shift -199–199°F (-111–111°C) 0

Proportional band of Output 1 0–360°F (0–200°C) 0: for ON-OFF control 18°F (10°C)

Integral (reset) time of Output 1 0–3600 seconds 120

Derivative (rate) time of Output 1 0–1000 seconds 40

AhY1

Hysteresis of Alarm 1 0–19°F (0–11°C) 0

AhY2

Hysteresis of Alarm 2 0–19°F (0–11°C) 0

hYST

Hysteresis of ON-OFF control 0–19°F (0–11°C) 0

ADDR

Interface address 0–40 0

LO.SC

Low scale of range.

Adjust for your process

Minimum value for the selected input to high scale 0°F

hI.SC

High scale of range.

Adjust for your process

Low scale to maximum value for the selected input 999°F

PL.1

Power limit of Output 1 0–100% 100%

PL.2

Power limit of Output 2 0–100% 100%

INPT

Input type selection J, K, T, E, B, R, S, or N-TC=J, K, T, E, B, R, S, or N type

T/C

PT100 DIN (PTDN), PT100 JIS (PTJS), 4–20mA, 0–20mA,

J-TC

UNIT

Display units QC =°C QF =°F PU =process units (Engineering °F

RESO

Resolution NODP =No decimal point 1DP =1 decimal place

2DP =2 decimal places (only when UNIT = PU)

NODP

CON.A

Control action of Output 1 DIRT =Direct (cool) action REVR =Reverse (heat) action

REVR

A1.MD

Alarm 1 mode

DVhI=Deviation high DVLO=Deviation low DBhI=Deviation band high DBLO=Deviation low FShI=Full scale high FSLO=Full scale low

DVhI

A1.SF

Alarm 1 special function

NONE=No special function LTCh=Latching alarm hOLD=Holding alarm LThO=Latching/holding alarm TOON=Timer on as time out TOOF=Timer off as time out

NONE

A2.MD

Alarm 2 mode Same as Alarm 1 mode

DVhI

A2.SF

Alarm 2 special function

NONE=No special function LTCh=Latch alarm hOLD=Hold alarm LThO=Latch/hold alarm

NONE

CYC

Proportional cycle time of Output

0–99 seconds, 0 for linear current/voltage output

20 for

relay output

CCYC

Cooling cycle time 0–99 seconds, 0 for linear current/voltage output

20 for

relay output

C.PB

Cooling P band 0–360°F (0–200°C) 18°F (10°C)

D-B

Deadband for PB and CPB -199–199°F (-111–111°C) 0

Page 12

5–4 Flow Chart of Tool Programs

The Tool Programs menu can be entered at any time by pressing

Manual Mode (hand control) Used if sensor fails.

Peak Process Value Stored minimum and maximum values.

Calibrate A-D converter

Fail Safe Defines the status of the outputs if the sensor fails.

HAND CONT

READ PEAK

CALI

A-D

FAIL

SAFE

h___

C___

hI.PV

LO.PV

T___

A___

D___

OUT.1

ALM.1

ALM.2

OUT.2

Indicates percentage power of output 1 (heating)

Indicates percentage power of output 2 (cooling)

Indicates maximum (peak) process value

Indicates minimum (peak) process value

Adjusts Cold Junction compensation code (range -19.9-42.7)

Adjusts Drift compensation code (range -6.6-6.6)

Select the status for Output 1: ON or OFF

Select the status for Alarm 1: ON or OFF

Select the status for Alarm 2: ON or OFF

Select the status for Output 2: ON or OFF

Long

Adjust the percentage of on-time for output 1 using the up and down keys. Range: 0-100%

Adjust the percentage of on-time for output 2 using the up and down keys. Range: 0-100%

Long

Resets the maximum process value

Resets the minimum process value

Calibrate the A-D converter and enter the Cold Junction compensation code

Calibrate the 0-20mA and enter it

Enter the Drift compensation code

Long

Enters the selection

Lock Parameters Parameter levels can be locked out to prevent tampering.

Configure Security Levels Parameters can be moved from one security level to another.

LEVL

=0: Puts parameter in Level 0 =1: Puts parameter in Level 1 =2: Puts parameter in Level 2

LOCK PARA

CONF

LEVL

LEV.0

LEV.1

LEV.2

ASP.1

Displays the rest of the parameters according to the standard sequence.

D-B

Select LOCK or FREE for all Level 0 parameters

Select LOCK or FREE for all Level 1 parameters

Select LOCK or FREE for all Level 2 parameters

Change the security level of the selected parameter

Exits Tool Programs

Long

Enters the selection

Page 13

5–5 Setting-Up Procedures

When power is applied, the model number and software version number of the controller will be displayed for 3.2 seconds, then all of the display segments and LED indicators will light up for 3.2 seconds. After this initial cycle, the controller will enter normal display mode, showing the process value in the upper display, and the set point value in the lower display. The upper display will flash continuously in the following cases:

1. while executing autotune program

2. while executing manual mode program

3. to warn that the next parameter is a higher level parameter (as the scroll key is pressed). The warning will remain for

3.2 seconds. If the scroll key is released after this duration elapses, the upper display will show the code of the next parameter, and the lower display will show its value. Otherwise, it will return to normal display mode.

The upper display will blink for a moment when a new value of a parameter is being written into the non-volatile memory. The upper display is also used to display error messages if an abnormal condition occurs.

Parameter Definitions

SV—Set Point Value This parameter is the desired target of the process. It can be adjusted within the range defined by the low scale value (Lo.SC) and high scale value (hi.SC). The default value is 212°F (100°C).

ASP1—Alarm 1 Set Point Value or Dwell Time This sets the levels at which alarm 1 will function if A1.SF (alarm 1 special function) is set for an alarm function. If A1.SF is selected for dwell timer (to.on or to.of), then ASP1 is the timer setting in minutes. The dwell timer starts counting when the process value reaches the set point value. See sections 5–10 and 5–13 for more details.

RAMP—Ramp Rate This controls the heating (or cooling) rate of the process. The setting is in degrees per minute. Set this parameter to zero if no ramp is needed.

OFST—Offset Value for Manual Reset This parameter will only function if the integral time (TI) is set to zero. OFST is then used to compensate for any deviation between the process temperature and the set point temperature. If the process temperature stabilizes below the set point, set a positive value for OFST; if the process temperature stabilizes above the set point, set a negative value for OFST. Wait for the system to stabilize, then make additional adjustments as needed.

ASP2—Alarm 2 Set Point Value This sets the levels at which alarm 2 will function if A2.SF is set for an alarm function. If A2.SF is set for cooling, alarm 2 will preform as a cooling output which is governed by CCyC, C.pb, and d-b. ASP2 will then have no effect.

SHIF—Shift Process Value This value will be added to or subtracted from the process value. This can be used to compensate if the sensor reads a different temperature than the item being sensed.

PB, TI, and TD—PID Values Proportional band, Integral (reset) and Derivative (rate) time constants. These must be set as close as possible to the process application requirements. See section 5–7 for more details.

AHY1, AHY2—Hysteresis Values of Alarm 1 and Alarm 2 These values define the deadbands for the alarms. The alarms will not change state until the temperature is outside the deadband.

HYST—Hysteresis Value of On-Off Control This parameter defines the deadband when on-off control is being used and PID control has been disabled.

Page 14

ADDR—Interface Address This parameter provides an identity code for the RS-485 interface. Note that no two controllers communicating with the same computer can have the same identity code. Ignore this parameter if the controller does not use the RS-485 interface.

LO.SC, HI.SC—Low/High Scale Range If thermocouple or PT100 is selected as the input type (INPT), these parameters are used to define the range of the set point adjustment. If linear process input is selected, these parameters are used to define the range of the process value and set point adjustment. See section 5–14 for more details.

PL.1, PL.2—Power Limit for Heating and Cooling Outputs These parameters limit the maximum output percentage of power for heating or cooling during warm up and in proportional band. If the control has relay or pulsed voltage outputs, the percentage of “on” time will be decreased. If the control has linear current or linear voltage outputs, the actual output levels will be decreased. These are only used for processes where heating or cooling at full speed would be dangerous or would produce unsatisfactory results. For normal applications, these parameters are set at 100%.

INPT—Input Type This is used to program the control for the type of input sensor used.

UNIT—Process Units This parameter is used to select the units displayed. For linear process input, Pu (process unit) can be selected in addition to °F or °C.

RESO—Resolution (Set Decimal Point Placement) This parameter defines the position of the decimal point in the process and set point values. no.dP=no decimal point;

1.dP=one decimal point; 2.dP=two decimal points. Note that 2.dP can only be used for linear process input when Pu is selected for UNIT.

CON.A—Control Action of Output 1 This selects reverse (heating) action or direct (cooling) action for output 1.

A1.MD, A2.MD—Alarm Mode Selection for Alarm 1 and Alarm 2 This sets the type of alarm required: deviation alarm, band alarm, or process alarm. See section 5–10 for more details.

A1.SF—Alarm 1 Special Function Use this parameter to select any special functions required for use with alarm 1. Latching or holding alarms can be selected (see section 5–10), or to.on or to.of can be selected if dwell timer function is required (see section 5–13).

A2.SF—Alarm 2 Special Function Select hold function or latch function for alarm 2, or select COOL to reconfigure alarm 2 as a cooling output.

CYC, CCYC—Proportional Cycle Time of Output 1 and Cooling Output Select a proper value for the process in accordance with the output devices used. Note that CCYC is only used if A2.SF has been set for cooling. See the following section on initial setup for further discussion.

C.PB, D-B—Cooling Proportional Band, Cooling Deadband Only used if A2.SF has been set for cooling. Otherwise, they may be ignored. See section 5–9 for more details.

Initial Setup

Use the keypad to view the value of each parameter. Use the up and down keys to set the correct value for each parameter. Note that the new value of each parameter is automatically entered into nonvolatile memory.

The adjustment of proportional cycle time (CYC and CCYC) is related to the speed of the process response and the output device fitted. For a faster process, it is recommended to use SSR (select SSR drive output) or SCR (select linear current or voltage output) to drive the load. The relay output is used to drive a magnetic contactor in a slow process. If a

Page 15

long cycle time is selected for a fast process, the process may become unstable as a result. Theoretically, the smaller the cycle time selected, the better the control that can be achieved. However, for a relay output, the cycle time should be as large as possible (while maintaining satisfactory control) in order to maximize the life of the relay.

The following table provides cycle time recommendations for avoiding premature relay failure:

Note: In an on-off control (when PB is set to zero) the cycle time parameter may be ignored.

FAIL-SAFE Configuration

FAIL-SAFE is a tool program used to define as on or off the status of output 1 (OUT1), output 2 (OUT2), alarm 1 output (ALM1), and alarm 2 output (ALM2) in the event of a failure. Press and release and repeatedly until FAIL-SAFE appears in the display windows. Press the scroll key until the desired output is shown in the upper display. Now press and hold the up or down key to change the status as shown in the lower display. Note that if the desired setting is different from the original one, a long scroll (pressing the scroll key for 3.2 seconds) will be required to enter the new value before proceeding to the next tool parameter. If the FAIL-SAFE status is not critical for a process if the controller should fail, then this section can be ignored.

LOCK Parameter

The flow chart in section 5–4 shows how to reach LOCK PARA and from there reach LEVEL (LEV.0–LEV.2), which is shown in the upper display, and the lock status of that level (LOCK or FREE), which is shown in the lower display. For example, if you select LOCK for LEV.2 and press the scroll key for 3.2 seconds to enter the selection, the all parameters in level 2 can no longer be changed. A LOCK message will appear in the upper display if someone attempts to change a locked parameter.

Configuring Security Levels of Parameters

One of the features of this controller is the ability to assign the security level for each parameter individually. One of four levels (level 0, level 1, level 2, or level 3) can be assigned to any parameter. The parameters with lower security levels will be displayed before parameters with higher security levels as one cycles through the parameters using the scroll key. Furthermore, level 3 parameters are not displayed on the front panel, so any unused parameters can be assigned security level 3 and removed from the viewing rotation completely.

As shown in section 5.4, to configure a new level for a parameter, press and to reach CONF LEVL, then press

to display the desired parameter. The lower display will indicate the level of the selected parameter. You can now change the level for that parameter using the up and down keys. Finally, press and hold for 3.2 seconds or longer to enter the new value. For example, if ASP1 and RAMP are set as level 0, PB, TI, and TD are set as level 1, ASP2 is set at level 2, and all other parameters are set as level 3, the scrolling sequence of parameters will be as follows:

Output Device

(OUT1 or Cooling Output)

Cycle Time

(CYC or CCYC)

Load (resistive)

Relay

20 sec. or more

recommended

10 sec. minimum

2A/250VAC

or contactor

5 sec. minimum 1A/250VAC

Solid State Relay Drive 1–3 sec. SSR Linear Current/Voltage 0.1 sec. Phase control module

ASP1

RAMP

TDSV

ASP2

Page 16

5–6 Auto-Tune

The auto-tuning process is performed at the set point. The process will oscillate around the set point during the auto-tuning process. Set the set point to a lower value if overshooting beyond the normal process value would be likely to cause damage.

The auto-tune program should be applied:

• During initial set-up

• When the set point is changed substantially from the previous auto-tune

• When the control results are unsatisfactory

When preparing to run the auto-tune program:

• Make sure that all parameters are configured correctly.

• Make sure that PB is not set to zero, because the auto-tune program cannot be run in on-off control mode.

• Set the set point at the normal operating process value (or at a lower value if overshoot is likely to cause damage) and

use normal load conditions.

• Press and hold the up and down keys for 3.2 seconds then release together. The upper display will flash while the

auto-tune program is running.

Auto-tune “teaches” the controller the main characteristics of the process. It “learns” by cycling the output on and off. The results are measured and used to calculate the optimum PID values for the process which are then automatically entered into the nonvolatile memory.

During the second period of the auto-tune program, the controller performs PID control to verify the results, and an OFST value is obtained and entered in the memory.

To stop the auto-tune program, press the up and down keys and release them together. The upper display will stop flashing, indicating that the auto-tune program has been aborted. Once the controller has entered the verifying period, auto-tuning cannot be stopped.

5–7 Tuning the Controller Manually

• Make sure that all parameters are configured correctly.

• Set PB to zero. Set HYST to minimum (0.1°F or 0°C).

• Set the set point at the normal operating process value (or at a lower value if overshoot is likely to cause damage) and

use normal load conditions.

• Switch on the power supply to the heater. Under these conditions, the process value will oscillate about the set point

and the following parameters should be noted:

1. The peak to peak variation (P) of the first cycle in °F or °C (i.e., the difference between the highest value of the first overshoot and the lowest value of the first undershoot).

2. The cycle time (T) of the oscillation in seconds (see figure below).

The control setting should then be adjusted as follows:

PB=P (°F or °C)

TI=T (seconds)

TD=T/4 (seconds)

Time

Page 17

The PID parameters determined by the above procedures are rough values. If the control results using the above values are unsatisfactory, the following rules may be used to further adjust the PID parameters:

Effects of PID adjustments on process response:

Adjustment Sequence Symptom Solution

Proportional Band (P)

Slow response Decrease PB

High overshoot or oscillations Increase PB

Integral Time (I)

Slow response Decrease TI

Instability or oscillations Increase TI

Derivative Time (D)

Slow response or oscillations Decrease TD

High overshoot Increase TD

P action

Set point

PB too low

Perfect

PB too high

Time

I action

TI too high

Perfect

TI too low

Time

Set point

D action

TD too low

Perfect

TD too high

Time

Page 18

5–8 On-Off Control

If the alarm output is configured as an alarm function, it basically performs as an on-off control. If you adjust the P band to PB=0, you can get an additional channel of on-off control with variable hysteresis. Hysteresis, also called differential or deadband, is measured in degrees. See the figure below for a description of on-off control.

On-off control may create excessive process variation from the set point, even if the hysteresis is set at the minimum possible value. When using on-off control, the parameters TI, TD, and CYC will have no effect on the system, and both manual mode and the auto-tune program will be disabled.

5–9 Cooling Control

Cooling control options:

Output

Configurations

Heating Output Cooling Output Adjusted Parameters

On-Off Cooling (no heating)

None OUT1

CONA=DIRT HYST SV

Proportional Cooling (no heating)

None OUT1

CONA=DIRT

PB, TI, TD, CYC, SV

Heating + On-Off Cooling

OUT1 ALM2

CONA=REVR A2SF=NONE A2MD=DVHI (or FSHI) AHY2, SV (or ASP2)

Heating + Proportional Cooling

OUT1 ALM2

CONA=REVR A2SF=COOL CPB, DB, CCYC, SV

P action

SP+HYST/2

SP–HYST/2

OUTPUT

Reverse 100%

Action

(CONA=REVR)

Direct 100%

Action

(CONA=DIRT)

Time

Page 19

Functions of CPB and DB: the cooling P band CPB and the deadband DB are measured in degrees.

5–10 Alarm

There are at most two independent alarms that can be made available by adjusting the alarm special function parameters A1SF and A2SF. While the descriptions in this section are based on alarm 1, they can also be applied to alarm 2.

• Latch Alarm: A1SF=LTCH When selected, the alarm output and indicator latch as the alarm occurs. The alarm output and indicator will be energized even if the alarm condition has been cleared, unless the power is shut off.

• Hold Alarm: A1SF=HOLD When selected in any alarm mode, prevents an alarm on power up. The alarm is enabled when the process value reaches the set point value.

• Latch and Hold Alarm: A1SF=LT.HO When selected in any alarm mode, prevents an alarm on power up. The alarm is enabled when the process value reaches the set point value. Thereafter, the alarm acts as a latch alarm as described above.

• Hysteresis (AHY1) adjustment

Example: no special function used with deviation high alarm, SV=100°C, ASP1=10°C, AHY1=4°C

Cooling

Output

DB Negative

100%

DB Positive

CPB

SV+DB

PV (∞F or ∞C)

•• No special function: A1SF= : Alarm on

A1MD

Deviation

high alarm

SV+ASP1

A1MD

Deviation low alarm

SV+ASP1

(ASP1 negative)

A1MD

Deviation band

high alarm

SV+ASP1

SV-ASP1

A1MD

Deviation band

low alarm

SV+ASP1

SV-ASP1

A1MD

Full scale

high alarm

ASP1

A1MD

Full scale low alarm

ASP1

Process proceeds

112 112112 112 112 108 108108 108 108

100 100100 100 100

Below 108∞C alarm off

Above 112∞C alarm on

Above 108∞C alarm stays on

OFF

Below 108∞C alarm off

Page 20

5–11 Viewing the Output Percentage Power

Scroll through the tool programs until you come to HAND CONTROL , then press the scroll key. The upper display will now show the process value and the lower display will show the percentage power of output 1 (for example, ). To view the cooling output, press scroll again. If alarm 2 is configured as a cooling output (A2SF=COOL), the lower display will now show the percentage power of alarm 2 (for example, ). If alarm 2 is configured as an alarm, this percentage power reading is invalid and should be ignored.

The range of percentage power is from 0–100%. If the unit is configured for on-off control, only 0 or 100 will be displayed. For a proportional control, the output percentage power represents the percentage of the duty cycle the output spends in the ON-state. (e.g., if cycle time CYC=10 seconds, and the output spends 4 seconds on and 6 seconds off during each duty cycle, the lower display would read )

5–12 Manual Control

Follow the procedures from section 5–11, then press and hold the scroll key for 3.2 seconds and release. The controller will now enter manual control mode. The upper display will begin to flash and the output percentage can now be adjusted using the up and down keys. Note that manual control mode is not available if the control is configured for onoff control (PB=0). If it is attempted, an error message (OPER) will appear in the upper display.

Manual control mode should be used:

• When teaching the process

• If the controller fails

Manual control mode is an open loop control. The process may rise to a dangerous temperature. Special attention

must be paid to the process in order to prevent damage to the system.

5–13 Ramp and Dwell

The controller can be configured to act either as a fixed set point controller or as a single ramp controller on power up. This function enables the user to set a predetermined ramp rate (RAMP) to allow the process to reach the set point temperature gradually, producing a “soft start” effect.

A dwell timer is incorporated in the controller. Alarm 1 can be configured to provide either a dwell function or a soak function when used in conjunction with the ramp function.

Ramp Function

If the ramp function is selected, the process will increase or decrease at a predetermined rate during initial power up, or with set point changes or process variations.

The ramp rate is determined by the “RAMP” parameter, which can be adjusted through a range from 0–99.99°F/minute (0–55.55°C/minute). If the “RAMP” parameter is set to zero, the ramp function is disabled.

In the example below, RAMP is set at 5.00°F/minute, the ambient temperature is 50°F, and power is applied at zero time. The process value climbs to the initial set point of 150°F over a period of 20 minutes. The process temperature is held until the set point value is changed to 175°F at 40 minutes. The process value then climbs to the new set point over a period of 5 minutes and the new set point is held. At 70 minutes, the set point value is decreased to 100°F and the process value falls to the new set point over a period of 15 minutes.

∞F

175

150

100

40 45

Time (minutes)

Page 21

Ramp and Soak Function

The soak function is enabled by configuring alarm 1 to act as a dwell timer. If A1SF is set for TOON (time out on), the alarm 1 relay will act as a timer contact, with the contact being open at power up and closing after the time set in ASP1 has elapsed. If A1SF is set for TOOF (time out off), the alarm 1 relay will perform the reverse action. If the heater (or contactor coil) is wired in series through the alarm 1 relay and the out 1 relay, the controller will act as a guaranteed soak controller.

In the example below, RAMP is set for 5.00°F/minute, A1SF=TOOF, and ASP1=40 (minutes). Power is applied at zero time, and the process climbs from the ambient temperature of 50°F to the set point of 200°F over 30 minutes. The dwell timer is activated upon reaching the set point and, after the soak time of 40 minutes, the alarm 1 relay will open, switching off the output. The process temperature will then fall at an undetermined rate.

Dwell Function

The dwell function is enabled by configuring alarm 1 to act as a dwell timer. If A1SF is set to TOON (time out on), the alarm 1 relay will operate as a timer contact with the contact being open on initial start up. The timer begins to count down once the set point temperature has been reached. After the amount of time set in ASP1 has elapsed, the alarm 1 relay will close. This function can be used to operate an external device such as a siren or a light (for example) to alert the operator when a minimum desired soak time has been reached.

In the example below, the ramp rate has been set to zero, A1SF=TOON, and ASP1=40 (minutes). Initial start up is at zero time, and the process climbs to the 200°F set point at the maximum rate. Once the set point is reached, the dwell timer begins to count. After 40 minutes, the alarm 1 relay closes. The controller will continue to act as a fixed set point controller.

5–14 Re-ranging Linear Process Inputs

Select an appropriate input type (INPT). Define the range by adjusting LOSC and HISC. In the example below, INPT=4–20 (mA), LOSC=0, HISC=100.0, and RESO=1DP. For a 4mA input, the process value will read 0 (LOSC), and for a 20mA input, the process value will read 100.0 (HISC). For a 10mA input, the process value will read 37.5. If the input signal is outside of the range defined by LOSC and HISC, an error message (LLEr or HLEr) will be shown in the upper display.

∞F

minutes

200

Process value

Alarm 1 output

OFF

Time (minutes)

∞F

200 F

Alarm 1 OFF

40 minutes

Alarm 1 ON

Time (minutes)

Page 22

5–15 Read Peak Process Values

The maximum and minimum values of the process value are continuously updated and stored in the memory after power up. Press both and to access the “READ PEAK” tool program. Press the scroll key to select or

in the lower display. The upper display will now show the high peak value or low peak value of the process,

respectively.

To reset the peak values, press and hold the scroll key for 3.2 seconds, then release. Both the low and high peak values will now be revised by the current process value.

5–16 Lock/Unlock Parameters

• Lock all of the parameters Press and hold both and for 3.2 seconds, then release. Keypad operation is now disabled to protect the parameters from tampering. To unlock the keypad, press and release the up and down keys.

• Lock all parameters in a given security level Refer to “LOCK Parameter” in section 5–5.

6. Recalibration

Do not proceed through this section unless there is a definite need to recalibrate the controller. All previous calibration data will be lost. Do not attempt recalibration unless you have the appropriate calibration equipment available. If the calibration data is lost, you will need to return the controller to your supplier who may charge you a service fee to recalibrate the controller.

• Equipment needed

1. Standard millivolt source with a range of 0–100mV with accuracy of ±0.01%.

2. Standard voltage source with a range of 0–10V with accuracy of ±0.01%.

3. Standard current source with a range of 0–20mA with accuracy of ±0.01%.

4. Standard ohm source with a range of 0–300 ohms with accuracy of ±0.01%.

5. Standard thermometer with a range of 32–122°F (0–50°C) with accuracy of ±0.36°F (±0.2°C).

6. A cooling fan or, ideally, a calibration fixture equipped with a fan and a push-button switch.

7. Thermocouple simulator.

• Calibration setup:

1. Select T/C input, UNIT=°F, RESO=1DP

2. Switch the power off

3. Disconnect the sensor wiring

4. Connect the input terminals of the controller to the signal sources according to the following diagram

5. Install a fan to blow on the cold-junction compensator located at the rear edge of the lower PCB to prevent it from

warming up.

100.0

(HISC)

LLEr

(LOSC)

HLEr

Input signal (mA)

Page 23

• Calibration procedures

1. Press both scroll and down keys, then release to access the tool programs. Repeat until appears on

the displays.

2. Press and release the scroll key. The lower display will show a number with the prefix “t”.

3. Use the up and down keys to change the value of the lower display until it matches the ambient temperature in °F

as measured by the standard thermometer.

4. Press the scroll key for at least 3.2 seconds, then release. The upper display will blink for a moment and then show

the ambient temperature in °F.

5. Press and release the scroll key. The lower display will show a number with the prefix “A”, and the upper display will

show 0.00.

6. Press and hold down push-button switch SW1 from the diagram above. While holding down SW1, Press and hold

the scroll key for at least 3.2 seconds, then release. The upper display will now show 20.00. Release SW1.

7. Press and release the scroll key. The lower display will show a number with the prefix “d”. If the number is not 0.0,

use the up and down keys to set it to 0.0, then press the scroll key for at least 3.2 seconds, then release.

• Verify calibration accuracy

1. Repeat step 1 from the calibration procedures as described above.

2. Press and release the scroll key until an “A” code is shown in the display. The display will indicate process value

with respect to the 0–20mA input. Feed a standard signal to the correct mA input terminals and examine the accuracy of the display.

3. Press and release the scroll key again until a “d” code is shown in the display. Now the display will indicate process

value with respect to the INPT type selected. Feed a standard signal to the appropriate input terminals and examine the accuracy of the display.

4. Press the scroll and up keys, then release quickly. The display will indicate process value with respect to the

PT100/DIN input. Feed a standard signal to the PT100 input terminals and examine the accuracy of the display.

5. Press the scroll and up keys, then release quickly. The display will indicate process value with respect to the 0–10V

input. Feed a standard signal to the voltage input terminals and examine the accuracy of the display.

• Warm-up drift correction for thermocouple input. After completing the calibration procedures above, connect a thermocouple to terminals 13 and 14 (observing polarity) and select the correct INPT for the thermocouple. Switch the power on and leave it on for at least 30 minutes. If the controller does not measure the correct temperature for the thermocouple, the following procedures may be used to correct the error.

1. Perform steps 1 and 2 from the calibration procedures.

2. Press and release the scroll key.

3. Press and release the scroll key again. Now the “d” code with zero value will show on the display.

4. Use the up and down keys to change the “d” code value until the upper display shows the correct temperature. The

“d” code is always shown in °C, regardless of the setting of the UNIT parameter.

5. Press the scroll key for at least 3.2 seconds, then release. The upper display will blink for a moment, then show an

accurate temperature. If the accuracy of the controller is still unsatisfactory, replace the controller.

mA-V-

COM+

TC-

PTA

1918

- +

200 ohm

SW1

10V

20mA

40mV

Page 24

7. Error Messages and Diagnosis

This procedure requires access to the circuitry of a unit connected to live power. Dangerous accidental contact with line voltage is possible. Only qualified personnel are to perform these procedures. Potentially lethal voltages are present.

Experience has proven that many control problems are not caused by a defective instrument. See the chart below and table 7.1 for some of the other common causes of failures.

• Line wires are improperly connected

• No voltage between line terminals

• Incorrect voltage between line terminals

• Connections to terminals are open, loose, or missing

• Thermocouple is open at tip

• Thermocouple lead is broken

• Shorted thermocouple leads

• Short across terminals

• Open or shorted heater circuit

• Open coil in external contactor

• Burned out line fuses

• Burned out relay inside control

• Defective solid-state relays

• Defective line switches

• Burned out contactor

• Defective circuit breakers

If the points listed on the chart have been checked and the controller still does not function, it is suggested that the instrument be returned for inspection. Do not attempt to make repairs. Be sure to use adequate packing materials to prevent damage during shipment.

Page 25

Table 7.1 Troubleshooting

Symptom Probable Cause(s) Solution(s)

1. Keypad doesn’t function -Bad connection between PCB and keypads -Clean contact area on PCB

-Replace keypads

2. LEDs will not light -No power to instrument

-Power supply defective

-Check power line connections

-Replace power supply board

3. Some segments of the display or LED lamps not lit or lit erroneously

-LED display or LED lamp defective

-Related LED driver defective

-Replace LED display or LED lamp

-Replace the related transistor or IC chip

4. Process display shows: SBER -Sensor break error -Replace RTD or sensor

-Use manual mode operation

5. Process display shows: LLER -Input signal beyond the low range, sensor fails

-Incorrect input type selected

-Replace sensor

-Check sensor or thermocouple type, correct input selection

6.Process display shows: HLER -Input signal beyond the high range, sensor fails

-Incorrect input type selected

-Replace sensor

-Check sensor or thermocouple type, correct input selection

7. Process display shows: ADER -A to D module damage -Replace module. Check for outside source of damage such as transient voltage spikes.

8. Process display shows: OPER -Incorrect operation of autotune

-Set point for autotune too low

-Manual mode does not allow on-off control

-Set P band greater than 0, repeat procedure

-Increase set point

-Increase proportional band

9. Process display shows: CSER -Check sum error, values in memory may have

changed accidentally

-Check and reconfigure the control parameters

10. Process display shows: NTER -Data failed to be entered into EEPROM -Replace EEPROM

11. Process display shows: OVER -Overflow error, data out of range during

execution of software program

-Check for electrical noise

12. Process display shows: LOCK -Attempt to change a locked parameter -Unlock parameter (see section 5–16)

13. Display unstable -Analog portion or A-D converter defective

-Thermocouple, RTD, or sensor defective

-Intermittent connection of sensor wiring

-Replace related components or board

-Check thermocouple, RTD, or sensor

-Check sensor wiring connections

14. Considerable error in temperature

indication

-Wrong sensor or thermocouple type/wrong input mode selected

-Analog portion or A-D converter defective

-Check sensor or thermocouple type and if proper input mode was selected

-Replace related components or board

15. Display goes in reverse direction

(counts down scale as process warms)

-Reversed input wiring of sensor -Check and correct

16. No heat or output -No heater power (output), incorrect output

device used

-Output device defective

-Open fuse outside of the instrument

-Check output wiring and output device

-Replace output device

-Replace output fuse

17. Heat or output stays on but

indicator reads normal

-Output device or power source shorted -Check and replace

18. Control abnormal or operation

incorrect

-CPU or EEPROM (non-volatile memory) defective. Key switch defective

-Operation of control incorrect

-Check and replace

-Read the operation procedure carefully

19. Display blinks, entered values

change by themselves

-Electromagnetic interference (EMI), or Radio Frequency interface (RFI)

-EEPROM defective

-Suppress arcing contacts in system to eliminate high voltage spike sources. Separate sensor and controller wiring from “dirty” power lines. Ground heaters

-Replace EEPROM

Page 26

TEMPCO Electric Heater Corporation 607 N. Central Avenue Wood Dale, IL 60191-1452 USA Tel: 630-350-2252