Despatch PROTOCOL Installation Manual

PROTOCOL™

DIGITAL OVEN CONTROLLER

INSTRUCTION MANUAL

P/N 116087

REV. 9/97

E-72

Prepared by:
Despatch Industries
P.O. Box 1320
Minneapolis, MN 55420-1320
Customer Service 800-473-7373

Notice

Users of this equipment must comply with operating procedures and training of
operation personnel as required by the Occupational Safety and Health Act (OSHA)
of 1970, Section 6 and relevant safety standards, as well as other safety rules and
regulations of state and local governments. Refer to the relevant safety standards
in OSHA and National Fire Protection Association (NFPA), section 86 of 1990.

Caution

Setup and maintenance of the equipment should be performed by qualified
personnel who are experienced in handling all facets of this type of system.
Improper setup and operation of this equipment could cause an explosion that may
result in equipment damage, personal injury or possible death.

Thank you for choosing Despatch Industries. We appreciate
the opportunity to work with you and to meet your heat
processing needs. We believe that you have selected the
finest equipment available in the heat processing industry.

At Despatch, our service does not end after the purchase
and delivery of our equipment. For this reason we have
created the Service Products Division within Despatch. The
Service Products Division features our Response Center for
customer service. The Response Center will direct and
track your service call to ensure satisfaction.

Whenever you need service or replacement parts, contact
the Response Center at 1-800-473-7373: FAX 612-781-

5353.
Thank you for choosing Despatch.
Sincerely,

Despatch Industries

Despatch Product Warranty

Parts, Materials and Labor

Despatch warrants all parts and materials to be free from defects in material and workmanship for a period of one (1) year from the
date of shipment unless otherwise mutually agreed upon in writing, or 2,000 hours of operation, whichever occurs first. (Note:
Laboratory oven electric heaters are warranted for a period of five [5] years from date of shipment.)

Despatch will repair or replace, at Despatch’s option, FOB Despatch’s factory, parts and materials covered by this warranty.
Despatch is not responsible for parts or material failures resulting from misuse, abuse, inadequate preventive maintenance, acts
of nature, or non-conforming utilities, including electrical, fuel supply, environmental and intake/exhaust provisions. This warranty
also does not cover normal wear or routine maintenance parts and materials expressly designed as expendable/consumable and
replaceable.

Labor services for parts and materials replacement and repair to support this warranty are available at Despatch’s normal service
fees. This service is provided worldwide by a network of factory trained professionals.

Terms and Conditions

The foregoing warranty shall be deemed valid and binding upon Despatch if and only if the Customer:

1. Installs, loads, operates and maintains the equipment supplied hereunder in accordance with the instruction manual
provided upon delivery and product labeling affixed to the subject equipment.

2. Agrees to follow the Emergency Procedure spelled out below.

Exclusions/Limitations of Liability

This warranty DOES NOT cover expenses incurred in the process of diagnosing and/or repairing equipment resulting from:
a) operator error, b) attempted service or modifications by other than Despatch authorized technicians, c) any use of the equipment
which is inconsistent with the operation manual or labeling, d) inadequate preventive maintenance, or e) acts of nature, such as
floods, fire, earthquake, or acts of war or civil emergency.

Despatch shall not, in any event, be liable for indirect, special, consequential or liquidated damages or penalties, including loss of
revenue, profits or business opportunities resulting from interruption of process or production. Despatch shall further be held
blameless for any damages or expenses resulting from delays in our attempts to diagnose and repair the equipment, unavailability
of spare parts or inaccessibility of the equipment. Specifically excluded from this warranty is responsibility for internal and external
corrosion damages to the equipment.

Non-Compliance

Despatch reserves the right to suspend and withhold service as provided under this warranty in the event of non-compliance by
the Customer to any terms and conditions of this warranty. Further, Despatch is held harmless for any loss of production, incurred
expenses, and other inconveniences due to suspension of service under this non-compliance provision.

Emergency Procedure

In an emergency situation, Customer agrees to: a) immediately shut off fuel or energy supply (gas and electricity), b) call 911 for
emergency assistance if needed, and c) call Despatch Service.

THE FOREGOING WARRANTY IS EXCLUSIVE AND IN LIEU OF ALL OTHER EXPRESS AND IMPLIED WARRANTIES
WHATSOEVER, AND SPECIFICALLY THERE ARE NOT IMPLIED WARRANTIES OF MERCHANTABILITY OR OF FITNESS FOR
A PARTICULAR PURPOSE.

THE FOREGOING WARRANTY IS NOT TRANSFERABLE IN SITUATIONS WHERE EQUIPMENT OWNERSHIP IS
TRANSFERRED TO ANOTHER PARTY.

Worldwide Phone [phone]; Worldwide Fax [phone]; North American Phone [phone]

Despatch Service

Please see reverse side for other service offerings BB5 (5/97)

Despatch

Service Support Programs

Despatch continues to deliver exceptional products backed by a strong sense of responsibility and drive for long term customer
satisfaction. Your partnership with Despatch can offer even higher value through your subscription to one of Despatch’s high value
service programs.

Warranty

Despatch’s exclusive, comprehensive service programs start with the warranty which is described on the other side of this
document. This warranty can be expanded immediately to meet your most stringent service needs. Despatch Service will be able
to answer your service questions and provide a quotation for the immediate expansion of your product warranty.

Immediate Service Response

The key to an effective service program is response. Wherever your location, Despatch is only a phone call away. Our North
American customers can reach Despatch at 1-800-473-7373. Worldwide customers can call 1-612-781-5363 or FAX
1-612-781-5485. Our Customer Service Technicians have over 200 years combined experience and access to detailed design and
manufacturing documentation specific to your Despatch unit(s). This exacting level of service is a benefit only Despatch can provide
and means that you can expect speedy, accurate and the most cost effective response.

Field Service Network

A worldwide network of factory trained Service Professionals is available to support your Despatch equipment. From routine repair
to certified instrument calibration, the Despatch service network is positioned to respond to your needs. As a manufacturer of custom
equipment, our service programs are customized to meet your specific needs regarding:

1. Service scope

2. Response time

3. Preventive maintenance frequency and content

4. Payment method

Sustained Service Support

At Despatch, long term customer satisfaction means more than just responding quickly and effectively to our customers’ service
needs. It means offering comprehensive customer support well beyond the scope and duration of our initial warranty. Despatch
offers two basic service packages which are customized to each individual customer’s need. These service packages are titled Full
Service and Preventive Maintenance Plus+ service agreement products. Each is unique in the industry and offer the following
benefits:

1. Priority response for minimum production interruption

2. Preventive maintenance for longer product life

3. Discounts on parts and services

4. Various payment plans to ease budgeting and recording expenses

5. Reduce purchase ordering costs

Worldwide Phone [phone]; Worldwide Fax [phone]; North American Phone [phone]

Despatch Service

TABLE OF CONTENTS

INTRODUCTION ..................................................... 1

THEORY OF OPERATION .............................................. 2

Protocol ....................................................... 2

Keypad Controls ................................................ 3

Status Indicator LEDs ............................................ 4

Operating Modes ................................................ 5

Manual Mode ............................................. 5

Timer Mode ............................................... 5

Program Mode ............................................ 5

Calibration Zero Offset ............................................ 6

Tune Setting ................................................... 7

Protocol Hi-Limit ................................................. 8

INSTRUCTIONS ...................................................... 9

Start-Up ....................................................... 9

Manual Mode .................................................. 10

Startup .................................................. 10

Run .................................................... 10

Stop .................................................... 11

Timer Mode ................................................... 12

Startup ................................................. 12

Run .................................................... 13

Manually Stop ............................................ 13

Program Mode ................................................. 15

Startup .................................................. 15

Run .................................................... 18

Manually Stop ............................................ 18

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APPENDIX ......................................................... 19

Special Instructions ............................................. 19

Control Instrument .............................................. 20

Tune Mode .............................................. 20

Tuning Worksheet ......................................... 22

Calibration Mode .................................... 23

Calibration Recovery ................................. 28

Diagnostics Mode .................................... 29

Power Failure ....................................... 30

Programming Examples and Outline ........................... 31

Example 1 - Manual Mode ............................. 31

Example 2 - Timer Mode .............................. 32

Program Mode ...................................... 33

Example 3 - Program Mode ............................ 36

Example 4 - Program Mode ............................ 37

Example 5 - Program Mode ............................ 38

Troubleshooting ................................................ 39

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INTRODUCTION

The special features of the Protocol™ include:

C PID Tuning
C Programmable up to 48 segments
C Built-in manual reset hi-limit control
C Built-in process timer
C Self-diagnostics
C Digital display
C Three (3) event outputs
C RS422/RS485 bi-directional communications capability
C Recursive profile capability

1

THEORY OF OPERATION

This section describes the Protocol installed in the LAC, LAD, LFD and LND Series
ovens.

Protocol

The ovens are equipped with a modular microprocessor based digital temperature
controller.

Figure 2. Main Display and Keypad on Protocol Control

The Despatch Protocol temperature controller is a dual functioning controller/high limit
instrument. The control portion of Protocol incorporates a microprocessor to digitally
control process variables with minimal temperature fluctuations.

The high limit portion of Protocol protects the product and/or the oven itself. If the
product being processed has a critical high temperature limit, the Hi-Limit parameter
should be set to a temperature somewhat below the temperature at which the product
could be damaged. If the product does not have a critical high temperature limit, the Hi­Limit parameter should be set to a value slightly higher than the highest programmed
setpoint to protect the oven equipment.

2

Keypad Controls

Table 1 Protocol Keypad Controls

Mode Display Code Function Description
Manual MANUAL Operation Single setpoint control
Timer TIMER Operation Single setpoint control with process timer
Program PROGRAM Operation Programmable control with three event outputs
Tune TUNE Configure Set instrument parameters
Calibrate CAL-MODE Service Performs instrument calibration
Diagnostics DIAGNOSE Service Performs instrument thermocouple tests, SSR

power level and event output tests.

Table 2 Protocol Touchkeys

Key Description

• To move up through any mode
– To move down through any mode

+ To increase a setpoint or parameter

- To decrease a setpoint or parameter
Home To move to the beginning of any mode or segment
Reset To reset the control when an error has been corrected or to view the profile number,

segment number, and the number of loops (repeat times) remaining.

Heater
On

Heater
Off

Start To start an operating mode
Stop To stop an operating mode

To initiate heater relay

To disengage heater relay

3

Status Indicator LEDs

Protocol has seven indicator LEDs that provide the following relevant information to the
user.

Table 3 Protocol Indicator LEDs

LED Function
Power on Lights when the power on pushbutton is pressed.
Heater relay Lights when a mode is ready for operation and the heater on key is pressed.
Soak Deviation Lights when the process temperature is not held within the user-specified soak

deviation limits. The light turns off when the temperature is within the soak
deviation limit.

Over Temp Lights when the process temperature exceeds the high limit value. The over

temperature light remains lit until the Reset is pressed.

Control T/C Error Lights when Lights when Protocol receives a control thermocouple error. the

Reset key clears the error upon corrective action.

Hi-Limit T/C
Error

Lights when Protocol receives a hi-limit thermocouple error. The Reset key
clears the error upon corrective action.

The Despatch Protocol temperature controller has been designed for ease of use while
maintaining elaborate and versatile control capabilities.

4

Operating Modes

Protocol has three primary modes of operation: the Manual mode, the Timer mode and
the Program mode.

Manual Mode

The Manual mode is a single setpoint control mode that controls the process at the user
specified setpoint for an indefinite period of time. The Manual mode controls the oven
temperature within close limits as specified by the PID tuning parameters.

Timer Mode

The Timer mode is a single setpoint control mode with a built-in process timer that
starts timing either at the beginning of the process or at a user specified temperature.
As in the Manual mode, the Timer mode uses the PID parameters set in the tune mode.

Program Mode

The Program mode is a programmable ramp and soak control consisting of up to eight
profiles. Each profile consists of up to six segments for a total of 48 segments (8 x 6 =

48). Any one profile may be run recursively from two to 99 cycles or even continuously
if it is desired.

Each segment consists of a ramp and soak period. During the ramp period, the control
will track oven temperature. For example, a ramp is entered to heat from 100E C to
150E C in 50 minutes. Protocol will track the temperature 1E C every minute for 50
minutes. During the soak period, temperature is maintained as specified by the tuning
and soak deviation parameters.

Protocol will not allow a soak time to begin until the actual oven temperature is within
the soak deviation limit. This process is called assured soak. The ramp and soak
periods are adjustable from 0 to 99 hours, 59 minutes. Within each ramp and soak
period, up to three event outputs can be programmed either on or off.

The event relay is used for factory installed modifications, then disconnected before
shipping. Please consult the factory for information on connecting the event outputs.
When the events are connected, the user has the capability of controlling relays,
solenoid valves, etc., throughout the programming cycle.

5

Calibration Zero Offset

The Calibration Zero Offset (CZO) of Protocol is factory preset and tested for the
specified operating conditions. Special instructions for accessing the tune mode to
change the CZO are referred to in the Appendix of this manual.

Figure 3. CZO Function in Tune Mode

The CZO may be useful to make the following small temperature corrections to the
control system.

C Correction of known sensor calibration errors.
C Correction of any known steady temperature offset between the heated

work-piece (load) and sensor. This is useful for applications where the sensor
cannot be located exactly at the work-piece.

C Alignment of temperature indications in a multi-zone/multi-controller application,

e.g., at ambient temperature.

Note that the CZO changes the value of the controlled temperature when used in
closed loop control. The CZO function can be represented by the equations:

Temp Indication (EF) = Sensor Temp (EF) - CZO% [100 (EF) - Sensor Temp (EF)]
Temp Indication (EC) = Sensor Temp (EC) - CZO% [38 (EC) - Sensor Temp (EC)]

The CZO function is a straight line pivoted around 100E F (38EC). Thus, the CZO
functions as an offset and has the ability to change the SLOPE of a temperature range.

6

Table 4 Calibration Zero Offset Examples

CZO Display Temperature

measured by sensor

0.0

4.0

10.0

10.0

-10.0

100 EF
150 EF
150 EF
300 EF
300 EF

Offset EF Temperature Indication

-20 E

A more useful formula is one the user can use to
calibrate Protocol to match the center of the chamber.
This requires a temperature measuring device with its
thermocouple junction located at the center of the
chamber. CZO can be directly calculated by:

0 E
2 E
5 E

20 E

NOTE: The CZO function is
easily set for specific operating
conditions.

100 EF
152 EF
155 EF
320 EF
280 EF

Tune Setting

The Protocol has been preset and tested for normal operating conditions. Special
instructions for changing the tune setting are referenced in the Appendix of this manual.

The Protocol on the oven can be manually tuned. For your convenience the factory has
tested and preset the PID action to its optimum values. These values need not be
changed under normal operating conditions.

Table 5 Factory PID Settings

Proportional Band
Reset Time
Rate Time

5 degrees
30 seconds/repeat
0 degrees/second

7

NOTE: Reset times greater than 35
seconds/repeat are not recommended.

Protocol Hi-Limit

Protocol will not let the high limit value drop below the setpoint value. In certain
situations, it may be necessary to change the setpoint first and then adjust the high limit
value.

It will be necessary to reset the hi-limit whenever it
has tripped. The hi-limit may be reset by first
allowing the oven chamber to cool slightly (or
increasing the parameter by several degrees) and
pushing the Reset key. During a high limit condition
the Over Temp LED will turn on thus deactivating
the heater.

WARNING: Never operate the
oven at a temperature in excess
of the maximum operating
temperature.

8

INSTRUCTIONS
Start-Up

An outline and examples for the Manual mode, Timer mode and Program mode are
referenced in the Appendix. A completed typical program worksheet accompanies all
programmable event outputs installed at the factory.

1. Start Fan.
a. Press Power on pushbutton. You will hear the recirculating fan start.
b. Check that the green Power on LED is on.

Figure 5. Protocol Control Panel

9