Isotech TTI-7-R Operator's Handbook Manual

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Model TTI-7-R

Precision Digital Thermometer

Operators Handbook

Isotech North America

158 Brentwood Drive, Unit 4

Colchester, VT 05446

Phone: (802)-863-8050 Fax: (802)-863-8125

www.isotechna.com

sales@isotechna.com

ENGLISH

IMPORTANT SAFETY INFORMATION

22/1/97

GENERAL

This instrument has been designed and tested to comply with the Electromagnetic Compatibility Directive 89/336/EEC and Low Voltage Directive 93/68EEC in accordance with EN 61010 -1 :1995 relating to the safety requirements for electrical equipment for measurement, control and laboratory use.

Before connecting the instrument to the main supply please ensure the following safety precautions have been read and understood.

SAFETY SYMBOLS

The following symbols are used to describe important safety aspects of th is instrument, these symbols appear on the instrument and in the operation instructions.

Attention Symbol:

Indicates a potentially hazardous condition exists and that it is necessary for the operator to refer to the instruction manual to ensure the safe operation of thi s instrument.

Hot Surface Warning:

Indicates a hot surface that may be at a temperature capable of

causing burns, refer to the instruction manual for further safety information.

Caution Risk of Electric Shock:

Indicates hazardous voltages may be present,

refer to the instruction manual for further safety information.

Protective Conductor Terminal:

For protection against electrical shock during a fault condition. This symbol is used to indicate terminals that must be connected to electrical ground before operating equipment.

SUMMARY OF SAFETY PRECAUTIONS

The following general safety precautions must be observed while operating or servicing thi s instrument. Failure to comply with these precautions may result in personnel i njur y or death.

INSTRUMENT ELECTRICAL EARTH

This instrument is designed as a Class 1 electrical safety ins ulat ion device. To ensure continued protection from electric shock the instrument chassis must be connected to an electrical ground. The instrument is supplied with an AC power cable with an earth connection.

LIVE CIRCUITS DANGER

Do not connect the power supply to or operate thi s instrument with the protective covers removed. Component replacement and internal adjustments must be made by qua li fied service personnel. Do not replace components with the power cable connected. Under certain conditions, dangerous voltages may exist with the power cable removed. To avoid inj ur ie s always disconnect power and discharge circuits before touching them.

DO NOT MODIFY THIS INSTRUMENT OR SUBSTITUTE PARTS

Because of the danger of introducing additional hazards; do not perform any unauthorized modification or i nst a l l substitute parts to the instrument. Only fuses with the rated current, voltage and specified type should be used, fai lu re to do so may cause an electric shock or f ir e hazard. Return the instrument to Automatic Systems Laboratories for service and repair to ensure the safety features are maintained.

DO NOT OPERATE IN EITHER DAMP OR EXPLOSIVE ENVIRONMENTS

This instrument is not designed to operate w h ile wet, in an environment of condensing humidity or in the presence of flammable gases or vapors. The operation of thi s instrument in such an environment constitutes a safety hazard.

HOT SURFACES DANGER

Equipment marked with a Hot Surface warning symbol should be regarded as operating at temperatures capable of causing burns. Do not touch, handle or transport hot components or l iqu id s un t il they are at safe temperatures. Care should be taken not to spill or splash water or volatile fluids on or into hot surfaces or liquids.

CERTIFICATION

Automatic Systems Laboratories certifies that th is product met it s published specifications at the time of shipment from our factory. A ll calibration measurements performed in the manufacture of t his instrument are traceable to the National Physical Laboratory (London).

ASSISTANCE

For after sales support and product service assistance please contact Automatic Systems Laboratories Customer Support Group. Contact information is provided in the operation instruction manual.

Contents

Table of Contents

1. INTRODUCTION.................................................................................................................1-1

1.1 Overview ...................................................................................................................1-1

1.2 Definitions and Terminology.......................................................................................1-3

1.3 Principles of measurement........................................................................................1-4

1.3.1 PRT measurement...........................................................................................1-4

1.3.2 Thermocouple measurement............................................................................1-5

1.3.3 Thermocouple reference junction compensation...............................................1-6

2. SETTING UP THE TTI-7-R ............................................................................................... 2-1

2.1 Safety information......................................................................................................2-1

2.2 Unpacking the instrument..........................................................................................2-1

2.3 Voltage selection and fuse rating...............................................................................2-2

2.3.1 Setting the Voltage and Fuse Rating.................................................................2-2

3. ABOUT THE TTI-7-R ........................................................................................................ 3-1

3.1 The Front Panel ........................................................................................................3-1

3.2 On/Off switch and internal battery.............................................................................. 3-1

3.3 The Function Keypad ................................................................................................3-2

3.4 About the TTI-7-R Display ......................................................................................... 3-4

3.5 Thermometer inputs..................................................................................................3-8

3.6 Rear panel .................................................................................................................3-9

3.6.1 AC Power Input Socket..................................................................................3-10

3.6.2 Rating plate ....................................................................................................3-10

3.6.3 Input channel expansion card .........................................................................3-10

3.6.4 RS232/IEEE 488.2 Communication interface card ..........................................3-10

3.6.5 Analogue output .............................................................................................3-10

3.6.6 Name plate.....................................................................................................3-10

4. MEASURING TEMPERATURE...........................................................................................4-1

4.1 Measurement uncertainty and traceability .................................................................4-1

4.2 International temperature scale .................................................................................4-1

4.3 Thermocouple measurement introduction ..................................................................4-3

4.3.1 Connecting thermocouples ................................................................................4-4

4.4 PRT measurement .................................................................................................... 4-4

4.4.1 PRT linearization functions ...............................................................................4-6

5. OPERATING THE TTI-7-R ................................................................................................. 5-1

5.1 About the display screen ...........................................................................................5-1

5.2 About function keys ..................................................................................................5-3

5.3 Power-up sequence .................................................................................................. 5-4

5.3.1 Self-Test ..........................................................................................................5-4

5.3.2 System Configuration....................................................................................... 5-5

5.4 Setting up Measurement Options ..............................................................................5-6

Contents - 1

Contents

5.4.1 Selecting thermometer input channel. .............................................................. 5-6

5.4.2 Selecting differential input measurement .......................................................... 5-6

5.4.3 Setting up a PRT measurement....................................................................... 5-7

5.4.4 Setting up a PRT measurement with user defined probe memories.................. 5-9

5.4.5 Setting up a PRT measurement: checking/editing probe memory co-eff. values..

...................................................................................................................... 5-10

5.4.6 Selecting thermocouple type.......................................................................... 5-11

5.4.7 Selecting the reference junction compensation method.................................. 5-12

5.4.8 Selecting ext. ref. junction PRT linearization whose temperature is measured by

a PRT connected to the same channel. ........................................................................... 5-13

5.5 Selecting Screen Display Options........................................................................... 5-14

5.5.1 Selecting measurement units ........................................................................ 5-14

5.5.2 Selecting display resolution modes................................................................ 5-14

5.5.3 Selecting relative temperature measurement .................................................5-14

5.5.4 Using the measurement trigger function [Run/Hold] .......................................5-15

5.5.5 Selecting PRT measurement sense current................................................... 5-15

5.6 Data Logger ............................................................................................................ 5-17

5.6.1 Data logger functions ..................................................................................... 5-17

5.6.2 Setting up the data logger ..............................................................................5-17

5.6.3 Configuring the Scanner ................................................................................ 5-18

5.6.4 Configuring the Timer. .................................................................................... 5-19

5.6.5 Configuring the data log memory ................................................................... 5-21

5.6.6 Starting the data log.......................................................................................5-22

5.6.7 Reviewing log results ..................................................................................... 5-23

5.6.8 Reviewing log statistics .................................................................................. 5-24

5.7 Setting up the basic controls .................................................................................. 5-25

5.7.1 Review system configuration.......................................................................... 5-25

5.7.2 Setting up the TTI-7-R ................................................................................... 5-26

5.7.3 Configuring the communications interface. ..................................................... 5-28

5.7.4 Setting up Trigger Mode................................................................................. 5-30

5.7.5 Displaying the firmware version ...................................................................... 5-31

5.7.6 Adjusting the display contrast........................................................................ 5-31

6. CALIBRATING THE TTI-7-R .............................................................................................6-1

6.1 TTI-7-R Instrument calibration ................................................................................... 6-1

7. COMMUNICATIONS INTERFACE .....................................................................................7-1

7.1 Introduction............................................................................................................... 7-1

7.2 Fitting the Interface................................................................................................... 7-2

7.3 Overview of the RS-232 Serial Interface .................................................................... 7-3

7.3.1 The RS-232 Connector. .................................................................................... 7-4

7.3.2 Pin Connections............................................................................................... 7-4

7.3.3 RS-232 Settings............................................................................................... 7-5

7.3.4 RS-232 Operating Modes ................................................................................. 7-5

7.3.5 RS-232 Interface Commands ........................................................................... 7-6

Contents - 2

Contents

7.4 Programming the Interface ........................................................................................7-6

7.4.1 Introduction ......................................................................................................7-6

7.4.2 Command Tree.................................................................................................7-7

7.4.3 Command Directives ........................................................................................7-7

7.4.4 Command Syntax .............................................................................................7-8

7.5 IEEE-488.2 Common Command Group ....................................................................7-10

7.5.1 IEEE-488.2 Common Command Summary.....................................................7-10

7.5.2 IEEE-488.2 Common Commands ..................................................................7-10

7.6 Measurement Command Group ..............................................................................7-14

7.6.1 Measurement command summary...................................................................7-14

7.6.2 CONFigure Commands...................................................................................7-14

7.6.3 MEASure Command .......................................................................................7-18

7.7 SENSe Command Group........................................................................................7-20

7.7.1 Sense command summary.............................................................................7-20

7.7.2 Sense Commands .........................................................................................7-20

7.8 Mathematical Operation Commands........................................................................7-22

7.8.1 CALCulate:AVERage command summary ......................................................7-22

7.8.2 CALCulate:AVERage commands ....................................................................7-22

7.9 Route Command Group ...........................................................................................7-23

7.9.1 Route command summary. .............................................................................7-23

7.9.2 Route commands ...........................................................................................7-23

7.10 Trigger Command Group.....................................................................................7-25

7.10.1 Trigger command summary ............................................................................7-25

7.10.2 Trigger commands..........................................................................................7-25

7.11 System Related Commands ...............................................................................7-29

7.11.1 System command summary...........................................................................7-29

7.11.2 System commands .........................................................................................7-29

7.12 DATAIogger Command Group..............................................................................7-31

7.12.1 Datalogger command summary.......................................................................7-31

7.12.2 Datalogger commands ...................................................................................7-31

7.13 Status Reporting Structure AND Commands ......................................................7-34

7.13.1 The Status Reporting System is summarised in the following diagram.............7-35

7.14 Command Summary...........................................................................................7-39

7.15 Analogue Output.................................................................................................7-42

7.15.1 Specification...................................................................................................7-42

7.75.1 Default Settings..............................................................................................7-42

7.15.1 Analogue Output Connection..........................................................................7-42

8. OPTIONS AND ACCESSORIES ........................................................................................8-1

8.1 Accessories ..............................................................................................................8-1

8.2 High = PRTs ..............................................................................................................8-1

8.3 Low = PRTs .............................................................................................................. 8-2

9. SPECIFICATIONS .............................................................................................................9-1

9.1 Pt100 resistance thermometer measurement............................................................ 9-1

Contents - 3

Contents

9.2 Thermocouple measurement............................................................................................ 9-1

9.3 Internal battery operation ................................................................................................. 9-2

9.4 Supply ...................................................................................................................... 9-2

9.5 Environmental........................................................................................................... 9-2

9.6 Data communication interface options ...................................................................... 9-2

9.7 Analogue output option............................................................................................. 9-3

9.8 Display...................................................................................................................... 9-3

9.9 Physical....................................................................................................................9-3

9.10 Pt100 System accuracy ....................................................................................... 9-3

10. CLEANING AND MAINTENANCE................................................................................... 10-1

10.1 Cleaning............................................................................................................. 10-1

10.2 Preventive Maintenance...................................................................................... 10-1

10.3 General Safety Warning .....................................................................................10-1

11. SERVICE AND WARRANTY........................................................................................... 11-1

11.1 Technical Support .............................................................................................. 11-1

11.2 Returned Instruments ......................................................................................... 11-1

Contents - 4

1.1 Overview

The TTI-7-R Precision Thermometer is a high accuracy instrument

designed for laboratory and industrial temperature measurement and

calibration applications.

Features include:

• unique dual capability for both thermocouple and resistance

thermometer measurements;

• number of input channel can be expanded from two to ten

channels;

• large graphic LCD display for temperature measurement values

as well as configuration settings and statistical results;

• advanced functions include differential measurement, four

programmable scanning routines, programmable timer, data

logging to none volatile memory, statistical reporting;

• analogue output, IEEE 488 and RS232 communication

interfaces available for automated monitoring and calibration

applications;

• internal battery provides up to 20 hours mains free operation for

remote measurement and data logging applications.

The TTI-7-R will operate with any Pt25 (25 Ohm) and all 2, 3 and 4-wire

Pt100 (100 Ohm) platinum resistance thermometers as well as most

standard international thermocouple types. Temperature measurement

units are selectable by single front panel key operation; °C, °F,K Base measurement units mV,  are also displayed.

Resistance accuracy is better than ±4m for Pt100 400 Ohm range and ±1.5m for Pt25 100 Ohm range (over full range of –200 to 100°C

at +20°C ±2°C). This is equivalent to temperature measurement

precision of ±15mK for Pt25 thermometers and ±10mK for Pt100

thermometers. Total system measurement uncertainties as low as

±20mK are possible when the TTI-7-R is used with a calibrated

reference thermometer.

1. Introduction

Page 1-1

Introduction

Overall system accuracy depends on the PRT quality and calibration. See Section

9 for details of the system measurement accuracy specification.

Standard miniature and 4mm instrument sockets allow convenient connection for

thermocouple inputs. Connection sockets incorporate integral temperature

compensation sensors making high accuracy thermocouple measurement

possible without the use of an external reference junction.

Standard features of the TTI-7-R Precision Thermometer include:

• direct temperature measurement display in °C, °F,K;

• 2 x Pt 25 or Pt100 channel inputs on front panel using 4mm gold plated

spade lug connectors or wire/banana plugs;

• 2, 3 and 4 wire PRT probe measurement;

• Thermocouples B,C,D,E,J,K,N,R,S,T,U,W

• 1 to 20 probe coefficients for ITS90 or CVD entered and stored from

programming PRT calibrations;

• High Accuracy to 0.01 deg.C over –200 to 660 deg.C

• High Resolution 0.001 deg.C for 25/100 Ohm PRT’s and 0.01 deg.C for TC’s;

• Measuring Range –200 to 1100 deg.C for PRT’s and 0 to 2315 deg.C TC’s;

• PRT self-heating and measurement current polarity selection;

• illuminated display;

• compact rugged case;

• 2 to 10 channel expansion with rear panel SPRT, RTD, and TC modules;

• Automatic Cold Junction compensation for TC’s;

• Switched DC (current reversal) option to eliminate thermal e.m.f.s on PRT’s;

• Internal data logging and storage of 4000 measurements;

• Statistical data internally (Min, Max, Peak/Peak, Average, Std. Deviation) ;

• Differential (Difference between any 2 channels connected) ;

• PC interface (RS232) included;

• Portable 20 hour use using internal battery + charger fitted or mains supply;

Page 1-2

Introduction

1.2 Definitions and Terminology

i. 0°C = 273.15K

ii. 1 mK (milli-Kelvin) = 0.001 °C (one milli-degree Celsius)

iii. 1 milli-degree C = 0.001 °C = 1m°C = 1mK= 1.8m°F

iv. 1 milli-degree F = 0.001 °F = 1 m°F = 0.56mK = 0.56m°C

v. Alpha, or , is the temperature coefficient, or temperature

sensitivity, of the platinum wire used in PRTs. In general, the

greater the alpha value, the better the PRT thermometer

measurement reproducibility, stability and performance.

vi. Abbreviations for platinum resistance thermometers include: PRT

(Platinum Resistance Thermometer)

Pt100 (PRT with nominally 100 resistance at 0°C) RTD (Resistance

Temperature Device) vii. Thermocouples are referred to as a TC

element or TC sensor.

viii. The TTI-7-R 's thermocouple connection sockets are often referred

to as a temperature compensated reference junction. See Section

1.3 for more details.

ix. System accuracy refers to the overall, combined accuracy of the

TTI-7-R and thermometer.

Key functions and menu options are described as [Function] in the

text or the actual keytop is shown.

General warning symbol. This indicates that a

hazardous condition or general danger may exist.

You must read the relevant sections in the

Operator's Handbook before operating the

instrument.

Page 1-3

Introduction

1.3 Principles of measurement

1.3.1 PRT measurement

The TTI-7-R measures the voltage (Vt) developed across the unknown

sensor resistance (Rt) and the voltage (Vs) across a stable internal

reference resistance (Rs) connected in series and passing the same

current. The voltages are in proportion to the resistances so the

thermometer resistance is derived from: Rt = Rs x Vt / V

This technique achieves immunity from slow moving time and

temperature drift in the electronics as it is not affected by voltage

measurement gain variations or current source fluctuations.

In the same way that AC resistance measurement eliminates thermal

EMFs, switched DC achieves a similar advantage. Switched DC

works by reversing the current flow on alternate measurement cycles

and taking the average value, thereby cancelling any thermal EMF

offsets from the measurement.

For PRTs, the relationship between resistance and temperature varies

slightly from one PRT to another. Therefore, no matter how accurately

the TTI-7-R measures the PRT resistance, if the relationship between

resistance and temperature for a particular PRT is not known,

accurate temperature measurement is not possible.

The TTI-7-R uses PRT calibration data to overcome this problem and

calculates temperature from temperature conversion functions stored

in internal memory. This method enables the TTI-7-R accurately to

convert resistance to temperature, uniquely for each PRT used. It is

very important therefore that a PRT is used on the correct and

properly configured input channel.

The system accuracy is a combination of the TTI-7-R accuracy in

measuring PRT resistance and the calibration uncertainty placed on

the PRTs by the calibrating laboratory. Using the TTI-7-R with PRT

type 935-14-61, this is ±0.020°C for temperatures from -80°C to

+350°C. See section 9.1 for PRT measurement performance details.

Page 1-4

Introduction

1.3.2 Thermocouple measurement

As well as the PRT resistance measurement facility the TTI-7-R also

functions as a precision milli-voltmeter. Designed for high accuracy

measurement over the EMF voltage range of all standard base and

precious metal thermocouples, the TTI-7-R achieves a basic voltage

accuracy of better than 3µV

(at +20 °C ±2 °C) over the full measurement range and significantly

better over smaller ranges. See Section 9.2 for thermocouple

measurement performance details. Thermocouple EMFs are

converted to temperature using the NIST monograph 175

linearization functions. Special types C and D use the linearizations

specified by ASTM E988.

The voltage input connection is specially designed to minimise the

thermal gradient between the terminals. This is particularly important

when the internal reference junction compensation is used, as any

temperature difference at the connection junction will influence the

measurement result. The connection junction is introduced in

Section 1.3.3 below.

Page 1-5

Introduction

1.3.3 Thermocouple reference junction compensation

The electrical connection between the thermocouple element and the

TTI-7-R input connector is often referred to as the internal reference

junction. All standard thermocouple reference functions are defined

relative to 0°C. To eliminate the physical need to reproduce this

temperature inside the TTI-7-R , the actual connection temperature

is accurately measured with an internal PRT. This temperature is

converted to an equivalent EMF and added to the actual

thermocouple voltage measurement, thereby correcting for the

connection temperature.

For high precision thermocouple measurement applications, i.e.

calibration, an external reference junction may be used. Using an

external reference junction eliminates the uncertainties associated

with reference junction compensation.

Page 1-6

2.1 Safety information

Please read and follow these important safety instructions:

• Read the safety information sheet at the beginning of this

handbook before operating the TTI-7-R ;

• Make the necessary electrical safety and connection checks. In

particular, select the correct line voltage and make sure that the

correct AC power fuse is installed. Incorrect voltage or fuse

selection present both an electrical safety and a fire hazard.

2.2 Unpacking the instrument

When you unpack the TTI-7-R thermometer, check that the following

items are present before starting to use the unit:

• 1x TTI-7-R thermometer

• 1 x AC power cord

• 1x Operator's handbook

• 1x Calibration certificate

Please contact the ISOTECH NA Technical Services Group

immediately if any of these items are missing or damaged.

2. Setting up the TTI-7-R

Page 2-1

Setting up the TTI-7-R

2.3 Voltage selection and fuse rating

The AC Power Input Unit incorporates a voltage selector and fuse

holder, to enable the TTI-7-R operating voltage and fuse rating to be

selected for the local AC electricity supply. The table below describes

the correct voltage selection range and fuse to use.

Voltage Selection

Voltage Range

Fuse Type

100V 90-110V T630mA (250V AC)

120V 108- 132V T630mA (250V AC)

220V 198-244V T315mA (250V AC)

240V 216-264V T315mA (250V AC)

WARNING: DO NOT CONNECT THE POWER

CABLE UNTIL THE VOLTAGE AND FUSE RATING

OF THE INSTRUMENT HAVE BEEN CHECKED

AND CHANGED IF NECESSARY.

2.3.1 Setting the Voltage and Fuse Rating

Lever open the Power Input Unit from the top with a flat bladed

screwdriver. Inside is a plastic cam: remove this and replace it so that

the voltage to be set is displayed through the window as detailed in

Figure 2.1.

Where fused plugs are connected to the AC power cord, the correct

fuse rating is 3 Amps. The AC power cord provided with the TTI-7-R is

colour coded in accordance with national standards to match the plug

type fitted, as follows:

Page 2-2

Setting up the TTI-7-R

Earth (protective conductor) Green Green/Yellow

Live Black Brown

Neutral White Blue

Figure 2.1 - Fused Power Input Unit and Voltage Selector

INSERT SCREWDRIVER TO LEVER DOOR OPEN

VOLTAGE SELECT PLASTIC CAM

FUSE HOLDER

Page 2-3

Setting up the TTI-7-R

This page has been left blank intentionally

Page 2-4

3. About the TTI-7-R

This section introduces you to the features and functions of the TTI-7-

R Precision Thermometer.

3.1 The Front Panel

Figure 3.1- Front Panel

On/Off switches

Function keys

Display

Thermometer inputs

3.2 On/Off switch and internal battery

The ON / OFF keys switch the TTI-7-R on and off. During power

on all TTI-7-R measurement functions are reset to their default state.

It is important to note that THE POWER OFF FUNCTION DOES

NOT DISCONNECT THE TTI-7-R FROM THE ELECTRICITY

SUPPLY. The power supply remains connected to the mains supply.

Page 3-1

About the TTI-7-R

Battery charging operation is unaffected by the ON / OFF

key operation.

The TTI-7-R 0 may be operated from the AC electricity supply or the

internal battery. Fully charged batteries provide approximately 8 hours

continuous operation. The internal battery charger operates

whenever the electricity supply is connected. Front panel LEDs

indicate connection to the AC electricity supply and when the battery

is charging.

The batteries are a sealed lead acid type and require no routine

maintenance. Continuous charging causes no harm to the batteries.

Operate the TTI-7-R from the mains when possible to ensure the

batteries are always fully charged.

<LOW BATTERY> indication is displayed when the batteries have

approximately 10% charge or 50 minutes operating time remaining.

To extend the battery operation time, switch the display backlight off.

See Section 5.6.1.

If the batteries are left discharged for a long time, they become

difficult to charge on the first re-charging cycle. During this first re-

charge, it may not be possible to turn on the TTI-7-R . Leave the TTI-

7-R connected to the AC electricity supply for at least 12 hours to

allow the batteries to fully re-charge before using the TTI-7-R again.

3.3 The Function Keypad

All TTI-7-R measurement and programming facilities are accessed

through the function keypad. A brief description of key functions is

given in the table below. For a detailed description of how to use the

keys to configure and operate the TTI-7-R , refer to Section 5.

Page 3-2

About the TTI-7-R

Table 3.1 Summary of basic key functions

Page 3-3

Key symbol Description Function

Direct function or Menu

Setting up Input Channels

Select input channel A0 to A4

Selects and displays measurement channel A0 to A4

Direct from keypad

Select input channel BO to B4

Selects and displays measurement channel BO to B4

Direct from keypad

Diff

Select differential measurement Ch1 Ch2

Relative measurement function which displays the difference between the Ch1 and Ch2 inputs

Direct from keypad

Setting up Measurement Options

SENS

Temperature sensor type

Selects sensor type and measurement configuration for the selected channel

UNIT

Measurement units

Selects measurement display units: °C, °F, K

Direct from keypad

RES

Measurement

display resolution

Selects measurement display resolution: Thermocouple: 0.1,

0.01 PRT:0.01, 0.001

Direct from keypad

ZERO

Measurement display zero function

Nulls the display at the current reading and displays measured values relative to the nulled value.

Direct from keypad

TRIG

Measurement run/ hold/single step

Display hold function, triggers single or continuous measurement.

Direct from keypad

Logging Data and Statistical Displays

MATH

Math display functions

Selects the math menu statistical display and function

CAL

Calibration menu functions

Selects the instrument calibration menu functions

Options and configuration

OPT

Setup options and functions

Selects the instrument configuration options menu and communication interface functions

About the TTI-7-R

(Table 3.1 continued:)

SCAN

Scanner, timer and data logger functions

Scanner, timer and data logger menu.

PRT measurement current

+ l

PRT measurement positive current mode

Positive PRT measurement current polarity selection

Direct from keypad

-I

PRT measurement negative current mode

Negative PRT measurement current polarity selection

Direct from keypad

AVE

PRT measurement current reversal mode

Measures average sensor resistance with successive positive and negative current polarity Default PRT measurement state

Direct from keypad

2

PRT measurement 2 current selection

2 measurement current division, reduces measurement current to allow PRT self heating effect to be calculated

Direct from keypad

Scroll and contrast control

Up command key; Display contrast, page scroll

Controls the display contrast and page scroll functions

Direct from keypad

Down command key; Display contrast, page scroll

Controls the display contrast and page scroll functions

Direct from keypad

3.4 About the TTI-7-R Display

The liquid crystal graphic display clearly indicates the measured

temperature and measurement status as well as displaying available

menu options and measurement analysis when selected. Whilst in

Temperature Mode (see Section 5.1), there are three possible

display layouts:

Page 3-4

About the TTI-7-R

Figure 3.2 - Main display layout (PRT measurement)

A1 Pt100 IEC751 / R0 = 100.000 a=3850 4-wre

+ 18.90 °C

Input = +106.591 Ohm Ave

XXXX/YYYY

Figure 3.3 - Main display layout (Thermocouple measurement)

A1 TC Type N

RJ Mode= Internal

+ 18.90 °C

Input = -0.170 mV RJ = +24.62 deg C

Mem Adr Rem

Page 3-5

Busy

LOBAT

Run Mem Adr

Zero

Rem

SLX

Busy LOBA

Run

XXX/YYYY

Zero SL

About the TTI-7-R

Figure 3.4 -Main display layout (Relative A1-B1 measurement)

A1-B1

- 0 . 1

°C

Busy

LOBAT

Adr

XXXX/YYYY

The table below describes the location of information as it appears in the

various display layouts:

Page 3-6

Run

Mem

Zero SL

About the TTI-7-R

Table 3.2 - Measurement mode display features

PRT measurement Thermocouple Relative Ch1 - Ch2

Selected channel temperature

Temperature difference between CM and Ch2

Input channel selected

Input channel selected CM - Ch2

Pt100 TC Not used

PRT linearization standard

Thermocouple type selected, letter designation

Not used

PRT alpha value

Reference junction mode

Not used

3, 4 wire measurement configuration

Not used Not used

Temperature display units

Measured input value in Ohms

Measured input value

in mV

Not used

Measurement current polarity

Reference Junction temperature if selected

Not used

Measurement status Measurement status Measurement status

Trigger run/ hold, single condition

Measurement zeroed indication

Measurement zeroed

indication

Measurement zeroed

indication

Low Battery indication Low Battery indication Low Battery indication

Re mote/Addressed remote operation

Remote/Addressed remote operation

Re mote/Addressed remote operation

R0 value in ohms Not used Not used

X samples taken of Y number of samples

Logging data to none volatile memory

Scanning mode ON SLx scan list

Page 3-7

About the TTI-7-R

3.5 Thermometer inputs

The TTI-7-R has two main thermometer input channels, the input

sockets are located on the instruments front panel.

The two input channels can be independently configured for

measurement of PRT sensors or thermocouples.

Separate connection is provided for PRTs and thermocouples,

enabling easy direct connection of most thermometer types.

PRTs are connected via the 5 pin DIN sockets. You may connect 2, 3,

or 4 wire PRTs as shown in Figure 3.5. See Section 5.3.3 on PRT

selection. Un-terminated platinum resistance thermometers may be

connected through an optional adapter box which is available as an

accessory, (Part Number FA-ADAP-250). Refer to the Accessory

section at the end of this handbook.

Figure 3.5 - PRT input connection configuration

PRT CONNECTION - 2 WlRE PRT CONNECTION - 3 WIRE PRT CONNECTION - 4 WIRE

(5-pin DIN connector) (5-pin DIN connector) (5-pin DIN connector)

Pt100

R100

View towards front panel connector

Thermocouples may be directly connected to the TTI-7-R either at the

standard miniature sockets or the two 4mm instrument sockets as

shown in Figure 3.6. Special adapter connectors are available for

connecting bare wire thermocouples to the TTI-7-R . These sockets

are within a temperature compensated isothermal block which

eliminates the need for an external ice point reference junction.

However, the TTI-7-R may also be used with an external ice point

reference for high precision measurement and calibration work.

Page 3-8

About the TTI-7-R

Figure 3.6 - Thermocouple input connection

THERMOCOUPLE

CONNECTION

LOW THERMAL EMF COPPER BANANA (4mm) PLUGS

3.6 Rear panel

Figure 3.7 - Rear Panel layout, showing all options

PRT expansion module ( op t ional)

Thermocouple expansion module (optional)

RS232or I EE E

Communications Interface (optional)

Analogue output (optional)

Voltage selector and fuse cover

Name plate

IE C power

connector

Rating plate

Page 3-9

About the TTI-7-R

3.6.1 AC Power Input Socket

Accepts an IEC type power connector.

The AC power input unit incorporates a voltage selection tumbler, to

enable the user to match the TTI-7-R to the local AC voltage

supply, and a power line fuse holder.

3.6.2 Rating plate

Instrument rating plate, contains the AC voltage selection and line

fuse rating, operating supply frequency range, the instrument

maximum power consumption and instrument serial number.

3.6.3 Input channel expansion card

Optional input channel expansion card slots. Blanking plates are

fitted if there is no input channel expansion cards.

3.6.4 RS232/IEEE 488.2 Communication interface card

Optional RS232/IEEE 488.2 communication interface card slot. A

blanking plate is fitted if there is no communication interface card.

3.6.5 Analogue output

Optional analogue output BNC socket. A blanking plug is fitted if

there is no analogue output.

3.6.6 Name plate

Instrument name plate, contains the manufacture name and

address details.

Page 3-10

4.1 Measurement uncertainty and traceability

Measurement is usually made on the assumption that there is a true

value. Whenever a measurement is performed it is unlikely that the

measured value will equal the true value. The difference between the

two values is the measurement error which will lie within the specified

limits of uncertainty. Uncertainty is defined as an estimate

characterising the range of values within which the true value lies.

By taking a statistically significant number of measurement samples, a

distribution of results will emerge. Confidence in the distribution

increases as more measurements are made. Using statistical

methods, the distribution may be described in terms of mean, variance

and standard deviation. The uncertainty or precision limit of a particular

measurement is characterised by this distribution.

Traceability is defined as the property of a measurement that may be

related to appropriate reference standards through an unbroken chain

of comparisons. Through traceability it is possible to demonstrate the

accuracy of a measurement in terms of SI units.

4.2 International temperature scale

The purpose of the International Temperature Scale is to define

procedures by which certain specified practical thermometers

including PRTs and thermocouples of the required quality can be

calibrated. The values of temperature obtained from them can be

precise and reproducible, matching at the same time the

corresponding thermodynamic values as closely as current technology

permits.

4. Measuring Temperature

Page 4-1

Since 1968 when the International Practical Temperature Scale of

1968 (IPTS68) was adopted, there have been significant advances in

the techniques employed in establishing temperature standards and

in the measurement of thermodynamic temperature. The

International Temperature Scale of 1990 (ITS-90) gives practical

effect to these improvements. Particular features are:

• ITS-90 specifies the use of the PRT up to the freezing point of

silver, 961.78 °C. The platinum 10% rhodium/platinum

thermocouple is no longer specified for use in the scale, though

it and other noble metal thermocouples will continue to be used

as secondary standards.

• New, more precise, fixed points have been introduced and

mathematical procedures for calculating resistance temperature

equivalents have been revised so as to reduce the 'non-

uniqueness' of the scale: that is, to reduce the differences which

occur between different, identically calibrated PRTs. In particular,

the calibration of a PRT can no longer be extrapolated beyond

the freezing point of zinc, 419.527 °C, but requires a

measurement at the freezing point of aluminium, 660.323 °C.

• Alternative definitions are permitted in certain sub-ranges, the

calibration of a PRT can be terminated at almost any fixed point.

This allows primary calibrations to be carried out with suitable

PRTs over reduced ranges, and will be of special importance to

metrology standards departments which need to make precise

measurements at ambient temperatures.

• The part of the ITS-90 scale which may be measured by PRTs

extends from 83.8058 K (-189.3442 °C) to 961.78 °C. The TTI-7-

is specified to measure temperature over the range

-200 °C to +962 °C. The actual range of temperatures which may

be measured depends on the type and range of the PRT.

Measuring Temperature

Page 4-2

Measuring Temperature

The ITS-90 scale has much improved continuity, precision and

reproducibility compared with IPTS68. The implementation of the

ITS-90 scale according to its definition calls for changes in

equipment and procedure compared with IPTS68, but lower

uncertainties of calibration are achievable in all parts of the range.

However, the instruments and equipment needed to implement the

ITS-90 scale in calibration laboratories will be substantially the

same.

4.3 Thermocouple measurement introduction

Very broadly the thermoelectric effect occurs when an electrical

circuit consisting of dissimilar metal conductors is subjected to a

temperature gradient. An electric potential or voltage is developed

along the conductors. This voltage potential varies proportionally with

temperature and provides a means by which to measure

temperature.

There are two categories of thermocouple:

• Rare metal, Platinum based types

• Base metal, Nickel based

Rare metal, platinum types are mostly used for high temperature

precision thermometry. Maximum temperatures of 1700 °C and

measurement uncertainties of up to 0.3 °C are possible. The

sensitivity of platinum based thermocouples is usually in the region of

10µV/ °C, which means that high accuracy, high resolution

measurements require sensitive instruments such as the TTI-7-R .

Base metal thermocouples easily account for the bulk of temperature

sensors used today, and offer the advantages of being easy to

package into a variety of sensor configurations and relatively low

cost. Base metal thermocouples operate over a wide temperature

range with high temperature types designed for use up to 1600 °C.

Temperatures above 2300°C are possible with new high temperature

tungsten rhenium types. Typical sensitivity figures of

Page 4-3

Measuring Temperature

>30µV/ °C characterise most of the base metal thermocouple

family.

Base metal thermocouples are easily affected by contamination

effects which results in decalibration and drift. This is especially

pronounced at high temperatures where drift figures of the order of

10 °C are possible. It is important to be aware of the particular

contamination effects and to select the correct thermocouple for the

measurement environment. The N type thermocouple offers the best

performance in terms of reproducibility and measurement

uncertainty, operating up to 1250 °C. It is the best choice for most

general measurement applications, calling for accuracy with low

time and temperature drift.

4.3.1 Connecting thermocouples

Thermocouples measure temperature difference. As all practical

thermocouples consist of at least 2 junctions, it is important when

performing absolute temperature measurement that one of the

junctions is referenced to a known temperature.

The reference junction and voltage measurement precision

significantly influence the overall temperature measurement

accuracy. Intermediate connection junctions such as connectors and

extension cables between the measurement thermocouple and the

TTI-7-R also influence the measurement result.

4.4 PRT measurement

The TTI-7-R will operate with either 25 Ohm SPRT’s/PRT’s or a

range of 2, 3 and 4-wire 100 Ohm PRTs. The best performance will

be achieved only where good quality PRTs are used from reputable,

proven sources. As with any measured parameter, the performance

of a measurement system depends upon its stability and

repeatability. Low quality PRTs are likely to reduce system

performance.

The relationship between temperature and resistance depends on

several factors, including the alpha value and the PRT calibration.

Page 4-4

Consequently more than one equation is required for resistance to

temperature conversion. Calibration data for the PRTs takes the

form of Callendar van Dusen coefficients.

ISOTECH NA Inc. provides a range of proven PRTs especially for

use with the TTI-7-R , as well as offering a service to provide

customised PRTs to meet individual customers' requirements.

High "alpha" PRTs: The best possible system accuracy is

achieved using high "alpha" (Ω) PRTs, or more correctly, PRTs

using high Ω (high purity) platinum wire.

Low "alpha" PRTs: Low Ω PRTs contain a higher level of impurities

in the platinum resistance wire used. This affects the resistance

value at a given temperature (the temperature coefficient). As

impurities already exist in the platinum resistance wire, additional

contamination has a reduced effect and hence low Ω PRTs are more

immune to contamination and are therefore better for industrial

applications. To ensure a robust PRT, the detector within the PRT is

contained within materials, which can themselves be the source of

contamination at elevated temperatures. The PRTs supplied by

ISOTECH NA Inc. have been optimized for the temperature ranges

for which they are specified and, when calibrated, are temperature

cycled to enhance stability in use.

PRTs which are used outside their design and/or calibration

temperature range, especially at higher temperatures, risk

irreversible alteration to their calibration either by induced thermal

stresses or by contamination.

Measuring Temperature

Page 4-5

Measuring Temperature

4.4.1 PRT linearization functions

The TTI-7-R provides 3 standard and 20 user definable algorithms

for converting resistance to temperature. The choice will depend on

the type of PRT and its calibration. See also Section 9, which gives

PRT sensor information.

IEC751 (1983):- used for un-calibrated industrial PRTs with

0.003850 "alpha" value, to provide a conversion of resistance to

temperature in accordance with the IEC751 (IPTS 68) standard.

• EN60751 (1992):- used for un-calibrated industrial PRTs with

0.003851 "alpha" value, to provide a conversion of resistance to

temperature in accordance with the

BS EN60751 (ITS 90) standard.

• US/JIS:- used for un-calibrated industrial PRTs with 0.003916

"alpha" value, to provide a conversion of resistance to

temperature in accordance with the JEMIMA standard.

Un-calibrated PRTs conforming to IEC751/DIN43760/BS1904 have

traditionally used the IEC751 pre-programmed standard, which

provides a conversion in accordance with published DIN43760 or

BS1904 tables. These tables were created using temperatures

defined by the superseded International Practical Temperature Scale

of 1968 (IPTS68) and have inaccuracies compared with the

International Temperature Scale of 1990 (ITS-90). ISOTECH NA Inc.

has included the values for standard coefficients from IEC751 and

the more recent

EN60751 standards. The use of EN60751 is now recommended for

use with uncalibrated industrial PRTs.

Page 4-6

Measuring Temperature

IEC751

Selecting IEC751 from the standard menu selects the standard

coefficients from IEC751 (DIN43760/ BS1904 -based on IPTS68).

The coefficients for IEC751 are as follows:

Ro A B C

IEC751 100 Ohms 3.90802 x 10

-3

-5.802 x 10-7 - 4.2735 x 10

-12

EN751

Selecting EN751 from the standard menu selects the standard

coefficients from BS EN60751 based on ITS90. The advantage of this

is that it removes the temperature conversion errors associated with

the old IEC751 standard which is based on the earlier and

superseded IPTS68. The coefficients for EN60751 are as follows:

Ro A B C

EN60751 100 Ohms 3.9083 x 10

-3

-5.775 x 10-7 -4.183 x 10

-12

US/JIS

Selecting US/JIS from the standard menu selects the standard

coefficients from JEMIMA for high alpha PRT reference

thermometers. The coefficients for US/JIS are as follows:

Ro A B C

JIS/US 100 Ohms 3.97478 x 10

-3

-5.8775 x 10-7 -3.4813 x 10

-12

Usr

Selecting Usr from the standard menu allows the coefficients

provided with calibrated PRTs to be used in converting resistance to

temperature.

Either 25 or 100 Ohm SPRT’s/RTD’s may be used and coefficients for

ITS90 or Callendar Van Dusen entered. The instrument recognises from

data entered under Ro if a 25 or 100 Ohm probe is being used and

automatically adjusts the measuring range and measuring current.

Page 4-7

Measuring Temperature

This page has been left blank intentionally

Page 4-8

5. Operating the TTI-7-R

5.1 About the display screen

The TTI-7-R display screen is your direct link to the instrument,

presenting you with information or menus that prompt you on what to

do next.

It has two modes:

• the Temperature Measurement Mode which displays status

information and a sequence of temperature readings;

• the Configuration Mode which lets you set up and configure

the equipment.

Figure 5.1 shows an example of the Temperature Measurement

Mode display. The top line of the screen gives status information: in

this example, an N type thermocouple is connected to input socket

A1 and the internal reference junction method has been selected.

The temperature reading is displayed in degrees Celsius.

Figure 5.1 - Example of Temperature Measurement Mode

A1 TC Type N RJ Mode= Internal

18.3

°C

Input = -0.170 mV RJ = +24.62 deg C Busy

Run

The keypad below the display screen controls the TTI-7-R . Some keys

perform a function directly. For example, pressing changes the

temperature units. Other keys switch the display to configuration

mode which allows you to select options through a series of menus.

The option menus all follow the same format. The configuration mode

is indicated on the screen by a dashed line displayed directly

Page 5-1

Operating the TTI-7-R

below the main reading. An instruction prompt under the dashed line

indicates the current menu. The available menu options are displayed

on the bottom row of the display as shown in Figure 5.2. Press the

corresponding function key to select an option.

Figure 5.2 - Example of Configuration Mode screen

A1 TC Type N

RJ Mode= Internal

Sensor Type?

T/C PRT Quit

Indicates current menu

Indicates menu options

A white guideline printed on the front panel helps you to link the

menu option printed on the screen with the correct key on the

keypad.

White guideline

indicating which key

to press

Page 5-2

Operating the TTI-7-R

5.2 About function keys

You only use the top row of function keys to select menu options. The

lower row of function keys are enabled only when entering numerical

data; these instances are covered later in this section. Both rows of

function keys are shown in Figure 5.3.

Figure 5.3 - Function keys

The [Quit] and [OK] menu options consistently use the QUIT/MATH

and OK/MEM keys. Use the [Quit] key to leave a menu or return to the Temperature Measurement Mode screen. Use the [OK] key to confirm a particular choice and continue to the next set of menu options.

Not all function keys are used to access the Configuration Mode. Some

just invoke the function which is printed on the key. For

example, pressing

4/UNIT

cycles you through a sequence of

Celsius, Fahrenheit and Kelvin temperature units. If you miss the

option you want, just continue until it is displayed again.

The rest of this section describes how to set up the equipment, log

data and review the results. It also describes how to modify some of

the settings, such as date and time. Some of these are reset to

default values every time the machine is switched on.

Page 5-3

Operating the TTI-7-R

5.3 Power-up sequence

The instruments power on/off is controlled from the

ON / OFF keys located on the TTI-7-R front panel.

On power-up, the TTI-7-R performs a memory self-test routine

followed by a system configuration check.

5.3.1 Self-Test

On power-up the TTI-7-R performs a memory self-test routine

Figure 5.4 - Memory Self-Test Display

Performing Self-Test.......

On successfully completing the memory self-test the TTI-7-R will

report PASSED and proceed with a system configuration check.

If the memory self-test fails the TTI-7-R reports the message FAILED

Press OK to restore defaults.

Figure 5.5 - Memory Self-Test Fail Display

Performing Self-Test......

Failed

Press OK to restore defaults

Press the [OK] key to restore the instrument variables to the factory

default values.

Page 5-4

5.3.2 System Configuration

On power-up the TTI-7-R performs a system configuration

check searching for input channel expansion cards or

communication card. The screen displays:

Checking system configuration

The following information is read from each card on detection and

displayed by the system configuration display for 2 seconds.

Communication card

RS-232, Baud rate, Character bits, Parity, Start bit, Stop bit.

IEEE488.2, Address.

Input channel expansion card

Card ID, Serial Number, Card type, Channel numbers.

Figure 5.6 - Example System Configuration Display

System configuration

RS-232 9600,8,0,1,2

Card A1 Sn12345 4Ch TC Ch A1 to A4 Card B1 Sn30123 4Ch PRT Ch B1 to B4

The system configuration can also be reviewed from the options

menu.

After the power-up sequence, the instrument begins its normal

operation.

Operating the TTI

-7-

Page 5-5

Operating the TTI-7-R

5.4 Setting up Measurement Options

This section describes how to set up the TTI-7-R for your

specific measurement requirements.

You need to select an input channel before configuring a probe.

5.4.1 Selecting thermometer input channel

To select an input channel with no input channel expansion cards fitted, press ′/A to select input channel AD or 1/B to select input

channel BO.

To select an input channel with an input channel expansion card

fitted, press ′/A to select channels [A0 to A4], press 1/B to select

channel [B0 to B4]. The screen displays:

Enter channel number: (A or B)

Quit

Enter the channel number from the TTI-7-R function keypad at the A or B prompt. Select [Quit] to return to the main display.

The selected channel number is displayed in the top left hand corner

of the display screen.

If a channel is selected that is not available the TTI-7-R will

display an error message channel not available and prompt for

a new channel number.

5.4.2 Selecting differential input measurement

Press 2/DIFF 1 to select differential measurement with no input

channel expansion cards fitted.

To select differential measurement with an input channel expansion

card fitted press 2/DIFF. The screen displays:

Enter channel number: (Ch1-Ch2):

Quit

Enter the channel numbers from the TTI-7-R function keypad, each

channel number consists of a letter A or B followed by a single

digit number, A and B are entered from the and function

Page 5-6

Operating the TTI-7-R

keys. A differential measurement can be taken from any two

available channels. Select [Quit] to return to the main display.

If a channel is selected that is not available the TTI-7-R will

display an error message channel not available and prompt for

new channel numbers.

The selected channels are displayed in the top left-hand corner of the

display screen.

The TTI-7-R will displays the difference between the input channels

[Ch1-Ch2].

5.4.3 Setting up a PRT measurement

Three standard PRT linearization functions are available. In addition,

20 user-definable memories are available for coefficients provided

with calibrated probes. These memories allow calibration coefficients

to be stored in the Callendar van Dusen form for high precision

temperature measurement.

2. For input channels [A0] and [B0], the Sensor type? menu will be

displayed. Select [PRT] option, the standard? menu will be

displayed.

Sensor type?T/C PRT

Quit

For PRT input channel expansion cards the Standard? menu will be

displayed:

Standard?

IEC US/ EN-

Rev 751 Jis 751 Usr Quit OK

3. Next select a linearization standard from the list displayed on the screen. Note that you cannot start measuring temperature until you have made this selection.

Page 5-7

1.To configure a selected channel press 3/SENS .

The TTI-7-R is pre-programmed with three standard linearization

standards (see Section 4.4.1) as follows:

i. [IEC751] IEC751 (1983)

ii. [EN751] BS EN60751 (1992)

iII. [US/JIS]

JEMIMA

To choose one of these linearization standards, press the

appropriate function key and then [OK] if you want to go on to

configure 3 wire or 4 wire measurement or configure another

channel. Otherwise press [Quit]. The previous 3 wire or 4 wire

settings will remain unchanged.

4. If you press [OK], the screen displays:

Connection?3W 4W

Quit OK

5. Select the connection option you want, select 4 wire measurement

when using 2 wire PRTs.

6. Se lect [Quit] to return to Temperature Measurement Mode.

7. To configure all the channels of an expansion card to the same set

up, select one of the channels on the card and follow steps 1 to 5

above. At the Connection? menu select [OK], the screen displays:

Select channel?

Ch- Ch+ All Quit OK

8. Select [All] to configure all the channels of the expansion card to the

same set-up.

9. [Ch-] and [Ch+] can be used to select a channel without returning to

the Temperature Measurement Mode.

10. On completion of configuring all the input channels select [Quit] to

return to Temperature Measurement Mode.

5.4.4 Setting up a PRT measurement with user defined probe

memories

Operating the TT

-7-

Page 5-8

Operating the TTI-7-R -R

Standard?

IEC US/ EN-

Rev 751 JIS 751 Usr Quit OK

2. Select the [Usr] option. The screen displays:

Enter Probe #(1-20):

Quit OK

3. Enter a number between 1 and 20 using the numbers on the keypad

and then [OK]. The number you have entered is shown on the top

line on the display. If you make an error, press

USER/OPTN

and re-

enter number. The TTI-7-R will only accept values in the range 1-20

and will signal an error if your entry is outside this range.

Page 5-9

1. Press 3/SENS and then the [PRT] function key. The screen displays:

Operating the TTI-7-R

5.4.5 Setting up a PRT measurement: checking/editing probe

memory co-eff. values

This allows you to assign coefficient values to probe memories or

check the values already assigned.

1. Press 3/SENS and if PRT and TC inputs used, the screen

requests [PRT] or [TC]. When only a PRT channel is

available (NO channel expansion modules fitted) the screen

shows:

Standard?

IEC US/ EN-

Rev 751 JIS 751 Usr Quit OK

2. Select the [Rev] option. If you have already selected one of

the three standard linearizations, the four pre-programmed

standard coefficients are displayed at the top of the screen.

These cannot be altered.

3. If you want to enter a new set of coefficients, press

User in ‘Standard’ screen above. The screen requests

a probe coefficient set 1 to 20. Enter an empty

memory box number, e.g. 11. The screen displays:

User 11 empty

Enter Quit

4. Select enter. The screen shows:

IPRT SPRTCVD ITS90

5. Select required probe coefficient type, e.g. SPRT, ITS90 and the screen shows:

Ro Ap Bp Cp >> Quit Ok

6. Select and enter each coefficient in turn. (If no coefficient

exists, do not enter any value). To enter the coefficient,

e.g. –3.98e-2. first put in a – sign, then the number 3.98

from the front panel keys. For the exponential form, press

the exponential key on the front panel (on the lower right

Page 5-10

side) and then the number 2.

7. Go to the next page >> to enter the other coefficients. Dp,

An, Bn, and Wt as in 6, above. Note: The coefficients

entered can be viewed at the top of the screen.

8. Select Ok:

Save new coefficients Yes No

Select Yes.

9. If you are entering CVD coefficients, select CVD in item 4

above. Then proceed as in items 5, 6 and 7 to enter the Ro,

A, B and C terms.

Note: The 20 probe memories are already calibrated with the BS

EN60751 standard when the unit is shipped. This lets you obtain

sensible results from the onset; you can go back and edit the probe

coefficients at a later date, not necessarily at the time you select

them.

5.4.6 Selecting thermocouple type

1. Press and then the [TC] menu key. The screen displays:

Thermocouple type?

B C D E J » Quit OK

2. Select one of the ten thermocouple standards supported; B, C, D,

E, J are displayed on the first screen: K, N, R, S, T on the second.

Switch between the screens with the [»] key. Type the appropriate

key and then [Quit]. Measurement will start as soon as you have

selected the standard you want. The thermocouple type is displayed

in the top left-hand corner of the screen.

Page 5-11

Operating the TTI-7-R

5.4.7 Selecting the reference junction compensation method

You can select the reference junction compensation method after

selecting the thermocouple type by pressing [OK] instead of [Quit].

The screen displays:

RJ mode?

Off Int Ext Quit OK

The menu options list the three reference junction methods

supported:

Menu option

Description When used

[Int]

Internal reference junction compensation using the TTI-7-R 's internal temperature compensated copper isothermal junction. This is the default mode.

For direct temperature connection with no external reference junction. High accuracy measurement, requiring no additional connection reference junctions.

[Ext]

External reference junction compensation using PRT measurement of reference junction. No measurement channels are lost as the reference channel PRT uses the corresponding input channel.

For temperature

controlled or ovenised

reference junctions.

[Off]

No reference junction compensation applied to the measurement. All measurements are made with respect to 0 °C.

Used with an external ice

point reference junction.

Suitable for highest

precision measurement.

Select the reference junction method with the appropriate function key.

If you have selected [Off] or [Int], you can now press [Quit] to start

measurement.

Page 5-12

5.4.8 Selecting ext. ref. junction PRT linearization whose

temperature is measured by a PRT connected to the same channel.

1. The [Ext] menu option allows you to set up an external reference

junction whose temperature is measured by a PRT connected to the

same channel. When you select [Ext] you are prompted to choose

the PRT linearization for this PRT, the screen displays:

Standard?

IEC US/ EN751 JIS 751 Usr Quit OK

2. This lets you choose one of three standard linearizations which can

be used with uncalibrated probes. A fourth option, [Usr], gives you

access to the 20 probe memories for Callendar van Dusen

coefficients provided with calibrated probes.

3. If you want to select one of the standard linearization options,

[IEC751], [US/JIS] or [EN751], press the appropriate function key

and then [Quit]. Reference junction information is displayed at the

top right hand corner of the screen, e.g.

RJ Mode= Ext US/JIS

4. If you want to access one of the probe calibrations already in

memory, press [Usr]. The screen displays:

Enter Probe #(1-20):

Quit OK

Use the keypad to enter the probe number and then press [Quit].

Section 5.3.5 describes how to enter user coefficients.

Operating the TTI-7-R

Page 5-13

Operating the TTI-7-R

5.5 Selecting Screen Display Options

This section describes how to modify information displayed by the TTI-

7-R . It covers:

5.5.1 Selecting measurement units

Press 4/UNIT to sequence between the three measurement units

available. These are Celsius (°C), Fahrenheit (°F) and Kelvin (K). The

measurement unit selected is applied to all temperature displays,

including logged data.

5.5.2 Selecting display resolution modes

Press +-/RES to toggle between the two display resolution modes

available. The table below gives the display resolutions for

thermocouple and PRT inputs. The TTI-7-R defaults to low resolution

mode when first switched on.

High

Low

Thermocouple 0.01

0.1

PRT 0.001 0.01

5.5.3 Selecting relative temperature measurement

In Zero mode, the TTI-7-R displays temperature relative to a fixed

reference point. Press 5/ZERO to store the current display value; this

will be subtracted from all subsequent readings. To cancel Zero

mode, either press 5/ZERO again, change the input channel, change

the sensor type or turn off the power.

When Zero mode is enabled, a Zero message is displayed in the

bottom left hand corner of the screen.

Page 5-14

Operating the TTI-7-R

5.5.4 Using the measurement trigger function [Run/Hold]

The TTI-7-R default trigger mode is Run/Hold. It can also be configured

to operate in single shot mode. Press the key to alternate

between continuous measurement (Run), and measurement hold

(Hold). Measurement hold mode stops all measurement operations,

freezing the current display value. It also halts all scanning and data

logging operations. When measurement hold is enabled, a Hold

message is displayed on the bottom line.

Press 3/TRIG again to resume measurement, scanning or data

logging operations. A Run message is displayed on the bottom line

and the message Busy flashes on every time a new temperature

measurement is taken.

Setting the trigger mode to single shot mode is described in Section

5.6.3. In single shot mode, the TTI-7-R remains in the hold state until

you press the 3/TRIG key; it then captures a single

measurement reading.

If you have scanning enabled this allows you to single step through the

scanning routine.

If the data logger is enabled all the spot readings will be stored in the

data log memory.

5.5.5 Selecting PRT measurement sense current

PRT measurement uncertainty can be affected by external EMFs and

PRT self heating. The TTI-7-R allows you to select the measurement

sense current magnitude and polarity so that you can evaluate the

magnitude of such external factors.

a) Selecting positive measuring current polarity (+I)

Press /+1 for positive measuring current polarity. The

measurement time is approximately 1.8 seconds per reading for

channels A and B, and 3.6 seconds for Ch1-Ch2 relative

measurement.

Page 5-15

Operating the TTI-7-R

b) Selecting negative measuring current polarity (-I)

Press for reversed or negative measuring current polarity. The

measurement time is approximately 1.8 seconds per reading for

channels A and B, and 3.6 seconds for Ch1-Ch2 relative

measurement.

c) Selecting average current

Press 9/AVE to select automatically alternated dc measuring current

polarity switching at a rate of approximately O.SHz. Thermal EMF

measurement errors are eliminated by taking the average value of the

forward and reverse polarity readings. The measurement time is

approximately 3.6 seconds per reading for channels A and B, and 7.2

seconds for Ch1-Ch2 relative measurement. The Average current

mode is the power up default condition.

d) Selecting 2 current multiplier

This option reduces current through the probes by 2 (half-power), to

determine any probe self heating. The best method of using this option

is first to let the sensor reach a steady temperature and note the value.

It may take some time to stabilise.

Press and immediately select the reduced current through

the probe will reduce the heating effect on the probe, and the value

displayed will represent the temperature change due to the reduced

current.

When the reading has stabilised, note the temperature change. Add

twice the temperature change to the original temperature (observing

the sign; the final temperature should be lower than the original

value). The result is the actual temperature with the effect of probe

self heating eliminated.

Page 5-16

Operating the TTI-7-R

5.6 Data Logger

The TTI-7-R is fitted with a very powerful easy to use data logger.

The data logger consists of three functions, each function can be

used independently, or all three functions can be combined to

provide the powerful data logger.

5.6.1 Data logger functions

Scan: The scanner function lets you switch between a number of

input channels. Up to four independent scanning lists can be

configured and stored in non-volatile memory. A scanning list

consists of a list of channels, the timer cycle delay, sample rate and

cycle count. Each scanning list can be quickly set-up, reviewed and

edited.

Timer: The built in timer can be programmed to control the cycle

delay, sample rate and the cycle count.

Mem: Up to 4000 readings can be stored to none-volatile memory with

a time and date stamp for review later.

5.6.2 Setting up the data logger

Press the SCAN key to bring up the data logger menu. The

screen displays:

Scanner is: Off Memory is: Off

Scan Timer Mem Quit OK

The first line of the menu shows the current configured state of the

data logger modules.

Scanner is: Indicates the scanner is OFF or the selected scan list

when the scanner is ON.

Memory is: Indicates the data logging to memory ON/OFF state.

Page 5-17

Operating the TTI-7-R

5.6.3 Configuring the Scanner

To access the scanning list menu, select [Scan] from the data

logger menu. The screen displays:

Scanning list is: Off

SL1 SL2 SL3 SL4 Edt Off Quit OK

Switching scanner on/off: Scanner OFF is the default state when

the instrument is powered up. To switch the scanner ON select one

of the scanning lists [SL1] to [SL4]. To switch the scanner OFF

select [Off] from the menu. The first line of the menu shows the

current state of the scanner.

Edit a scanning list: To edit a scanning list, first select the

scanning list to be edited, then select [Edt] from the scanning list

menu. The screen displays:

Scanning list edit: SL1

AD BO A1 A2 A3 A4 B1 B2

< > Add Del Quit OK

The scanning list edit menu can display up to eight channels on

each page at a time, only available channels in the system will be

shown.

To add or remove a channel from a scanning list, position the

flashing cursor over the appropriate channel using the [<] or [>]

options.

Use the [Add] or [Del] options to add or delete a channel to the

scanning list.

Active channels in the scanning list are shown in reverse text (white

on black), none active channels are shown in normal text (black on

white).

Figure 5.7- Example of a scanning list

Scanning list edit: SL1

BO A

1 A2 A3 A4

1 B2

< > Add Del Quit OK

Channels A0, A1, A2, A3 and B1 are active channels that will be

scanned, the remaining channels will not be scanned.

Page 5-18

5.6.4 Configuring the Timer

The instrument timer function can be programmed to control the

measurement sample rate, cycle delay and cycle loop count. Figure

5.8 details the timer flow diagram for single channel data logging,

figure 5.9 details the flow diagram for multiple channel data logging.

To access the timer edit menu, select [Timer] from the data logger

menu. For single channel data logging (scanner off), the screen

displays:

Cyc=Cont Delay=00:00:00

< > Clear Edit Quit OK

For multiple channel data logging (scanner on), the screen displays:

Cyc=Cont Delay=00:00:00 Rate=00:00:00

< > Clear Edit Quit OK

To set-up the timer, use the [<] and [>] options to position the

flashing cursor over the appropriate parameter to edit.

To set a parameter to its default value select [Clear].

To edit the parameter value select [Edit], the screen display:

Cyc=Cont Delay=00:00:00 Rate=00:00:00

Enter the required parameter value directly from the TTI-7-R

numerical key-pad and select [OK] to return to the timer edit menu.

Errors can

be cleared using the front panel key. Repeat the process for

each of the timer parameters.

Timer Parameters

Cyc= Sets the number of scanning cycles required (1 to 9999 or

continues), default value is continues.

Delay= Sets the required delay hh:mm:ss between scanning cycles

(00:00:00 to 99:59:59 seconds), default is 00:00:00.

Rate= Sets the required delay hh:mm:ss between samples

(00:00:00 to 99:59:59 seconds), default is 00:00:00.

Operating the TTI-7-R

Page 5-19

Figure 5.8 - Single channel timer flow diagram

Figure 5.9 - Multiple channel timer flow diagram

Page 5-20

Operating the TTI-7-R

5.6.5 Configuring the data log memory

The TTI-7-R can record up to 4000 readings in none-volatile data log

memory. You can analyse this data either while it is being logged, or

later, even when the TTI-7-R has been disconnected from the

mains. Reviewing statistics or logged data will temporarily suspend

recording of data.

To access the data logger memory menu, select [Mem] from the

data logger menu. The screen displays:

Memory is: Off Rev New On Off Quit OK

Switching data log to memory on/off: Data logging OFF is the

default condition when the equipment is powered up. To switch on

data logging, select [On]. Select [Off] to switch off data logging. The

screen message reflects the current data logging status e.g.

Memory is: OFF/Memory is: ON.

Clearing previously stored results: Select the [New] option to

delete all previously recorded data log results. The screen displays :

Clear the current log?

Yes No Quit

Press [Yes] to clear the log. As deleted data cannot be retrieved,

you are asked to confirm that this is what you want to do by pressing

[Yes] again. This takes you back to the previous screen. [Quit]

takes you to the Temperature Measurement screen.

You need to record some actual data before using the [Rev] option

on this menu as described in Section 5.5.3.

Operating the TTI-7-R

Page 5-21

Operating the TTI-7-R

5.6.6 Starting the data log

Once you have set up the scanner, timer and data log memory you

can start to log data.

The bottom line of the Running Mode screen now displays:

Hold SLx x/yyyy Mem

Where SLx indicates the scanning list the scanner will use, Mem

indicates that data logging to memory is On, x is the number of

samples recorded and yyyy is the number of samples required.

1. To start logging data, press the 3/TRIG key. The bottom line of the

display now shows the Run message, and the sample number

starts to increase with each sample taken.

2. At any point, you can halt data logging by pressing 3/TRIG again, and

the Hold message is shown. Logging will also switch to Hold

automatically once the TTI-7-R has logged the required number of

samples.

3. If the data log is complete i.e. the number of samples taken equals

the number of samples specified, logging stops and Hold is

displayed. You can restart data logging only after the existing log has

been deleted or the number of samples required has been

increased. The screen displays:

Clear the current log? Yes No

4. Press [Yes] if you wish to delete the current log. Press [Yes] again,

to confirm that this is what you want to do.

5. Once the log memory has been cleared, press 3/TRIG to start the

data logger.

Page 5-22

Operating the TTI-7-R

5.6.7 Reviewing log results

You can review logged data at any time, both during the actual

logging and after data recording is complete.

To review the data logger memory, select [Mem] from the data

logger menu. The screen displays:

Memory is: Off

Rev New On Off Quit OK

1. Sele c t [Rev] to examine the data log. This is displayed six records

at a time, arranged in five columns.

Log #

Indicates the log sample number from the logging

sequence Ch # Indicates the measurement channel Temp (cleg) Stored temperature value Date Date temperature reading stored (dd/mm/yy) format Time Time temperature reading stored (mm:hh:ss) format

2. An example 'page' of a data review screen is shown below:

Ch#

Temp(degC) Date

Time

17.897

20/04/98

14:38:40 14:38:41

3 A2

17.896

20/04/98

14:38:43

4 A3

17.897

20/04/98

14:38:44

5 A4

17.895

20/04/98

14:38:59

6 BO

17.895

20/04/98

14:39:01

3. Use the up/down control keys to scroll through the data.

5. Press ⇓ to scroll table down.

6. Press [OK] to go back to the Data Logging menu.

Page 5-23

4. Press ⇑ to scroll table up;

Operating the TTI-7-R

5.6.8 Reviewing log statistics

You can examine a statistical log analysis at any time, both during the

actual logging and after data recording is complete. Reviewing

statistical analysis will temporarily suspend logging of data. If the input

channel is changed during data logging, no statistical analysis report

will be displayed.

Statistics/Filtering ?

Stats Quit

2. Se lect [Stats] to examine the analysis report. The statistical

analysis displays values in the selected measurement units and

reports the following statistical information:

Number of samples Indicates the number of log samples analysed Min

Minimum temperature value of the logged data records

Max

Maximum temperature value of the logged data records

Mean

Arithmetic Mean temperature of the logged data records

Ptp

(peak to peak

value)

Range of logged data records (Min-Max)

SD Standard deviation value

3. An example 'page' of a statistical screen is shown below:

Analysis of current log (A: deg C) Number of samples: 50

Min : 17.893 Max : 18.275

Mean : 18.068 Ptp : 0.281 SD : 0.0850

Quit OK

1. Press OUT/METH to bring up the Statistics screen. The screen

Page 5-24

5.7 Setting up the basic controls

You can configure certain settings on the TTI-7-R by

pressing This takes you to the options menu. The screen

displays:

Options?

Sys Set Rem Conf Up I/F Trg Ver Quit

The table below gives a summary of all the available options.

Sys Conf Review system configuration Set Up

Display backlight on/off Keyboard beeper on/off

Set TTI-7-R clock time Set TTI-7-R clock date format dd/mm/yy, mm/dd/yy Set TTI-7-R clock date

Rem I/F

(lf RS232 remote interface card fitted)

Set remote interface Baud rate Set remote interface to Talk only mode (lf lEEE488.2 remote interface card fitted) Set IEEE

address Trg Select Trigger mode to Run/Hold or single shot Ver Review Model number, Firmware version number

5.7.1 Review system configuration

On power-up the TTI-7-R performs a system configuration

check searching for input channel expansion cards or

communication card.

The following information is read from each card on detection and

displayed by the system configuration display.

Communication card

RS-232, Baud rate, Character bits, Parity, Start bit, Stop bit.

IEEE488.2, Address.

Input channel expansion card

Card ID, Serial Number, Card type, Channel numbers.

To review the system configuration select Sys Conf from the

options? menu. The screen displays the system configuration.

Operating the TTI-7-R

Page 5-25

Figure 5.4 - Example System Configuration Display

System configuration

RS-232 9600,8,0,1,2

Card A1 Sn 12345 4Ch TC Ch A1 to A4 Card B1 Sn30123 4Ch PRT Ch B1 to B4

Quit

5.7.2 Setting up the TTI-7-R

1. Press [Set Up] in the menu. This allows you to:

• Switch the display backlight on/off;

• Set the keyboard beeper on/off;

• Set the TTI-7-R clock time;

• Set the TTI-7-R clock data format;

• Set the TTI-7-R clock date.

You access each of the options in turn, pressing [OK] to move on to

the next option or [Quit] to save the selection and return to the

Temperature Measurement screen,

Operating the TTI-7-R

Page 5-26

Operating the TTI-7-R

1. Backlight: At power up, the LCD backlight default is [On]. To switch

it off, select the [Off] option. This is useful when using the internal

batteries, and either operating the data logger or remotely monitoring

temperature for extended periods. Switching off the backlight will

extend the life of a fully charged battery from approximately eight to

14 hours.

2. Beeper: At power up the audible beeper key is [On]. To disable it,

select the [Off] option.

3. Time setting: The TTI-7-R clock time function is used to identify data

in logged records. The screen displays the current time. If you want to

change it, select [Chg].

Time is 07:00:32

Chg Quit OK

Enter the new time as a sequence of six digits in the format [Hour

Minute Seconds] using the 24-hour time format. Then select [OK].

The new time is displayed on the screen; you can correct it if

necessary by pressing [Chg] again and repeating the process.

USER/OPTN deletes the entire data entry.

4. Date format: The TTI-7-R calendar date format can be configured for

dd/mm/yy or mm/dd/yy. The screen displays the current format. If

you want to change it, select [Chg].

Date format is dd/mm/yy

Chg Quit OK

5. Date setting: The TTI-7-R calendar date function is used to identify data

in logged records. The screen displays the current date. If you want to

change it, select [Chg].

Date is 06/04/98

Chg Quit OK

Page 5-27

Enter the new date as a sequence of six digits in the selected date

format. For example, to set the date to April 6th 1998 in the format

dd/mm/yy, enter [0] [6] [0] [4] [9] [8] and then press [OK]. The new

date is displayed on the screen; you can correct it if necessary by

pressing [Chg] again and repeating the process.

USER/OPTN

deletes the entire data entry.

5.7.3 Configuring the communications interface

The TTI-7-R can be fitted with one of the following types of

communications interface card:

1. RS-232 serial communications interface

2. IEEE-488.2 parallel communications interface.

The optional communications interface lets you assign remote

control of the TTI-7-R to an external computer.

5.7.3.1 Configuring the RS232 communications interface

If an RS232 serial communications interface card is fitted, select the

[Rem I/F] option in the main configuration menu. If there is no

interface fitted, the TTI-7-R displays the message Option not

available.

The screen displays:

Talk Only

Baud Rate

Quit OK

Switching on Talk Only Mode: You use the Talk only Mode to send

results directly to a serial printer, without the need for a PC. In this

mode, the TTI-7-R continuously outputs temperature data and

measurement results to the RS232 serial port. Output data format is

covered in Section 7.

When you select the [Talk Only] option, the screen displays:

Talk only mode is OFF?

Chg Quit OK

Operating the TTI-7-R

Page 5-28

Select [Chg] to enable Talk Only mode. At power up, Talk Only

Mode is disabled i.e. the interface is in full talk/listen mode. The

TTI-7-R will remain in Talk Only Mode until it is switched off or

until you select the [Chg] option again from this menu. All

incoming serial interface commands are ignored when Talk Only

Mode is operating.

2. Setting baud rate: To change the RS232 serial data transfer

rate, select [Baud Rate] from the [Rem I/F] menu. The screen

displays the current setting. Press the [Chg] option to alter this

setting.

Enter new Baud rate

Quit OK

The RS232 communications interface serial rate data transfer

options are: 75; 110; 150; 300; 600; 1200; 2400; 4800; 9600;

19200 baud. The factory default value is 9600 baud.

Enter the new baud rate using the numeric keys on the keypad

and then select [OK] to save this setting and return to the

previous menu. For example, to enter 19200, you press [1] [9]

[2] [0] [0]. If you enter a baud rate which is not recognised by the

TTI-7-R , it displays an error message and you need to repeat

the

procedure. deletes the entire data entry.

Serial transfer data format is fixed at:

Start bit 1

Data word length 8 bits

Parity checking None Stop bit 1 XON/XOFF Not implemented

Operating the TTI-7-R

Page 5-29

Operating the TTI-7-R

5.7.3.2 Configuring the IEEE 488.2 communications interface

If an IEEE-488.2 parallel communications interface card is fitted,

select the [Rem I/F] option in the main configuration menu.

The screen displays:

Talk

Only Addr Quit OK

Select the [Addr] option, the screen displays the current selected IEEE address.

Instrument address is 7

Chg Quit OK

To change the address select [Chg] and enter the new address from the function key pad. Addresses in the range 0 to 30 are valid addresses. The default factory set address is 7.

5.7.4 Setting up Trigger Mode

There are two trigger modes available to control measurement and

data logging operations:

[Run] Run/Hold mode, continuous measurement option.

Pressing 3/TRIG in this mode alternates between

continuous measurement and measurement hold. The

power up default state is continuous measurement

operation.

[Sng] Single shot mode. Single measurement mode collects a

single measurement each time you press the 3/TRIG key

and pauses between key presses.

Page 5-30

Operating the TTI-7-R

Trigger mode is RUN/HOLD? Sng Run Quit OK

2. Select [Run] for Run/Hold measuring or [Sng] for single shot

triggering. Select [OK] to save the trigger mode setting and return

to the configuration menu. [Quit] saves the trigger selection and

returns you directly to Temperature Measurement Mode.

5.7.5 Displaying the firmware version

Select [Ver] from the configuration menu to display details about the

TTI-7-R . The screen displays:

Model TTI-7-R Version 4.0 16/12/97

Quit OK

Instrument Model number

Firmware

version

reference

Firmware issue date

5.7.6 Adjusting the display contrast

You can change the display contrast while in Temperature

Measurement Mode. Press and hold down the key or the

key until the display is adjusted correctly. Note that display

contrast is not reset when the TTI-7-R is switched off.

Page 5-31

1. From the configuration menu, press USER/OPTN. The screen displays:

This page has been left blank intentionally

Page 5-32

Operating the TTI-7-R

6.1 TTI-7-R Instrument calibration

The dc bridge measurement technique used in the TTI-7-R is inherently very stable and linear, better than ± 6 m over the full

range at +20 °C ±2 °C (equivalent to ± 15 mK with a Pt100 PRT).

However drift of reference components will occur with time making

periodic re-calibration necessary.

We recommend you return your TTI-7-R to an ISOTECH NA service

centre for recalibration at least every 12 months. Please contact the

ISOTECH NA Technical Services Group for recalibration advice and a

quotation.

Page 6-1

6. Calibrating the TTI-7-R

Options and accessories

This page has been left blank intentionally

Page 6-2

7.1 Introduction

The TTI-7-R can be fitted with one of the following types of

communications interface card:

RS-232 serial communications interface

IEEE-488 parallel communications interface

The optional communications interface lets you assign remote control

of the TTI-7-R to an external computer. The computer can also read

the measured value and instrument status.

Alternatively you can use the communications interface to log data

directly to a serial printer. See Section 5.5.2 for further details.

The cards plug directly into the instrument's main PCB assembly,

with the interface connector accessible on the rear panel. Interface

cards may be retro-fitted at any time. The TTI-7-R 's software

automatically detects the type of interface card fitted at power-up. The

control parameters for the communications interface can be set from

the front panel.

The interface instruction set is common to both interfaces and

generally follows the IEEE488.2/SCPI protocol.

7. Communications Interface

Page 7-1

Options and accessories

7.2 Fitting the Interface

WARNING: Switch off the instrument and

remove the AC power cord before removing

the instrument case. ANTI-STATIC

PRECAUTIONS MUST BE TAKEN WHILE

INSTALLING THE INTERFACE CARD.

1. Remove the six screws holding the top half of the instrument case

(see figure 7.1) and lift off vertically, taking care not to stretch or

break the ground connection to the case cover (green/yellow wire).

2. Remove the two screws holding the communications interface

blanking plate located on the rear panel.

3. (IEEE only) Remove the four screws holding the rear panel to allow

the interface output connector to fit.

4. Fit the interface card in socket J18 on the instrument's main PCB,

ensure the connector is firmly located.

5. (IEEE only) Replace the instrument rear panel and secure the four

mounting screws.

6. Secure the interface to the rear panel with the two screws from the

blanking plate.

7. Refit the instrument top case and replace the six securing screws.

Figure 7.1 - Fitting an interface PCB

Page 7-2

7.3 Overview of the RS-232 Serial Interface

This conforms to specification ANSI/EIA/TIA-232-E-1991 Interface

Between Data Terminal Equipment (DTE) and Data Circuit-

Terminating Equipment (DCE) employing serial binary data

interchange.

Signal levels; MARK (logical "1"); -3V to -15V

SPACE (logical "0"); +3V to +15V

Data is transferred using the TXD (transmit data) and RXD (receive

data) lines.

Hardware handshaking for each character transfer uses the RTS

(request to send) and CTS (clear to send) lines. RTS is an output

from the instrument that indicates its receiver status. When asserted

(low), it indicates that it is ready to receive another character. When

negated (high), the instrument receiver buffer is full and cannot

receive another character until the buffer is processed (if the PC

sends one, it may be lost). As soon as space becomes available in

the receiver buffer, RTS is re-asserted to allow the PC to send the

next character.

When the instrument detects receipt of a command terminator

character, RTS is negated whilst the command line buffer is read

and validated. This is to prevent the PC sending further characters

whilst a command is being validated. Following validation, RTS is re-

asserted to permit the next command to be transmitted by the PC.

CTS is an input to the instrument and controls the transmission of

characters. If the PC asserts CTS (low), then the instrument will

transmit the next character from the output buffer (if one is waiting).

If the PC negates CTS (high), then the instrument will not transmit

the character, but will wait until CTS is re-asserted. TXD will remain

in the mark (low) condition whilst CTS is negated. Note that

changing CTS during transmission of a character will not disrupt the

transmission of that character.

Communications Interface

Page 7-3

Options and accessories

7.3.1 The RS-232 Connector

RS-232 connection is via a 9-way (socket) D-type connector on the

back panel as shown in Figure 7.2.

Figure 7.2 - RS-232 Connector

View towards rear panel RS232 connector

=Not connected on

TTI-7-R

7.3.2 Pin Connections

Computer TTI-7-R

25-Pin Connector

9-Pin Connector

Function

9-Pin Connector

Function

Rx 3 Tx

Tx 2 Rx

GND 5 GND

DSR

6* 4*

6* 7*

RTS

8 CTS

CTS 7 RTS

* Pins must be linked

To make an RS232 connection, use fully screened cable

assemblies to maintain EMC integrity. A 5-wire (TXD, RXD, GND,

RTS, CTS) cross over cable is recommended.

Three wire connection (TXD, RXD, GND) is not recommended, but

may be implemented by connecting RTS and CTS together at the

TTI-7-R end. In this case, the DTE must not send characters too

Page 7-4

Communications Interface

quickly as this will cause the TTI-7-R receive buffer (4 characters) to

overflow, leading to lost data.

7.3.3 RS-232 Settings

The RS-232 interface factory settings are:

9600 baud 8

character bits

No Parity 1 Start

Bit 1 Stop Bit

The serial communications data rate can be set from the instrument'

s front panel. Refer to Section 5.6.2 for configuration details. The

data format cannot be changed.

7.3.4 RS-232 Operating Modes

The instrument can be set from the front panel to operate in either

Talk Only Mode or Talk/Listen Mode. At power-up the instrument

defaults to Talk/Listen Mode.

Talk Only Mode

In Talk Only Mode, the interface ignores all incoming interface

commands and the instrument remains in Local control mode. The

result of each temperature measurement is sent to the interface

output with the resolution and units as per the main display.

This mode is useful for sending results directly to a serial printer

without the need for a PC.

Talk/Listen Mode

In Talk/Listen Mode, the communications interface permits remote

control of the instrument by an external computer. The measured

value and instrument status can also be read by the computer.

To enable communication in Talk/Listen Mode the instrument must

first be set for Remote Mode Operation.

Page 7-5

Options and accessories

7.3.5 RS-232 Interface Commands

SYSTem:REMote

Place the TTI-7-R in the remote mode for RS-232 operation. The

REM legend on the display indicates that the instrument is under

control of the remote interface. The front panel keys will be locked

out.

SYSTem:LOCal

Return the instrument to the Local mode from RS-232 operation. All

keys on the front panel are fully functional. This is the default at

power-up.

7.4 Programming the Interface

7.4.1 Introduction

All interfaces are programmed in a common language which is

based on SCPI (Standard Commands for Programmable

Instruments). Although similar in style, full conformance to the SCPI

and IEEE488.2 standards is not guarantied. The following sections

provide a guide to the structure and syntax of the programming

language.

Page 7-6

7.4.2 Command Tree

Commands are arranged as a hierarchical "tree", similar to the filing

system trees found in personal computers. Commands start at the

root level and progress down each level in more detail. The

complete path must be specified to access the lower level

commands. Only one command path per line is accepted.

7.4.3 Command Directives

Colon (:)

The colon is used to separate command keywords and

automatically move the path down to the next level. All new

command lines automatically start at the root-level. A colon must not

be sent as the first character. This is treated as a non-recognised

character and the "command error" bit (5) of the Standard Event

Whitespace (TAB or SPACE)

A whitespace character must be used to separate the first

parameter from a command keyword. If omitted, the "command

error" bit (5) of the Standard Event Register is set.

Comma (,)

If a command requires multiple parameters, a comma must be used

to separate parameters from one another in the parameter list.

Query (?)

Commands ending in a query (?) indicate that a response is

expected from the instrument. This is usually a request for a

measured value or status. Commands sent without a query request

the instrument to perform a function but not to send a response. The

instrument will not output a response without a query command

(except in Talk Only Mode).

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Options and accessories

Common Commands (*)

Commands beginning with an asterisk (*) are called common

commands and have a precise function as defined by the IEEE-

488.2 standard. All instruments behave in an identical way. These

commands are primarily concerned with control, reset, self-test and

status.

Command Terminators (CR) or (LF)

All messages sent to the instrument must be terminated with either

a carriage return (CR) character or a line feed (LF) character. It is

permitted to send (CR)(LF) to terminate a message; the (LF) is

ignored.

For IEEE-488, asserting EOI (end or identify) with the last character

sent is also treated as a message terminator. Message termination

always forces the command path back to the root-level ready for the

next command message.

7.4.4 Command Syntax

Most command keywords have both a long and short form. The bus

controller can send commands in either form and also in any

combination of upper and lower case characters. Instrument

responses, however, are always in short form, upper case.

Data Types

The bus controller can also send data in a range of formats, but the

instrument always responds in a precise format. There are four

principal data types:

Numeric Parameters are decimal numbers which include an

optional sign, mantissa, decimal point and exponent. Engineering

suffix units are not accepted. Ver 4.0 does not accept numeric

parameters.

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Discrete Parameters have limited values e.g. SINGIe, INFinite. Like

command keywords they can have long and short forms, upper and

lower case.

Boolean Parameters have a single binary value. The controller can

send OFF or 0, ON or 1, but the instrument response is always 0 or

String Parameters contain ASCII characters which are placed between

a pair of double quotation marks, i.e." ".

Input Buffer

The instrument receives messages into an input buffer and only starts

executing commands after receipt of a command terminator. The buffer

can store up to 100 characters including command directives and

terminator.

Sending a new command before the existing command is executed may

cause unreliable operation. It is advisable to query the Status Byte (*STB)

to check on the current status of the instrument before sending a new

command. Sending a command whilst the instrument is transmitting

(following a ? command) may result in the transmitted response being

corrupted. It is advisable to wait for the expected response to be

transmitted before sending a new command.

Output Data Format

Non-reading queries

<80 ASCII character string

Single-reading IEEE SDDDD.DDD(LF)

RS-232 SDDDD.DDD (CR) (LF)

RS-232 SDDDD.DDD, ..... , .. ,(CR)(LF)

Talk Only format

ChA: SDDDD.DDD degC (or F, K)

where

S= sign (+/-) D = decimal Digit (0-9) <CR> = carriage return character <LF> = linefeed character

The resolution and units will be as set by the last manual or bus

commands.

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Options and accessories

7.5 IEEE-488.2 Common Command Group

Common commands are device commands that are common to all

devices on the bus. These commands are designated and defined

by IEEE-488.2 standard.

7.5.1 IEEE-488.2 Common Command Summary

Mnemonic Description

*CLS Clears all event registers and error queue. *ESE <NRf> Program the Standard Event Enable Register.

*ESE? Read the Standard Event Enable Register. *ESR? Read the Standard Event Register and clear it. *IDN?

Returns the manufacturer, model number, serial number, Firmware issue.

*OPC

Sets the Operation Complete bit in the Standard Event Status Register after all pending commands have been executed.

*OPC?

Places an ASCII "1 " into the output queue when all Pending selected device operations have been complete.

*RST Return the instrument to the *RST default conditions.

*SRE<NRF> Programs the Service Request Enable Register.

*SRE? Reads the Service Request Enable Register.

*STB? Reads the Status Byte Register (bit 6 is MSS not RQS).

*TRG Sends a bus trigger to the instrument.

*TST? Performs a checksum test on ROM and returns the result.

*WAI Wait until all previous commands are executed.

7.5.2 IEEE-488.2 Common Commands

*CLS

Clears the Status Byte Summary Register and all event registers.

*ESE {<enable value>}

Enable bits in the Standard Event Enable Register. The selected bits

are then reported to the Status Byte.

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*ESE?

Query the Standard Event Enable Register. The instrument returns

a decimal value which corresponds to the binary-weighted sum of all

bits set in the register.

*ESR?

Query the Standard Event Register. The instrument returns a

decimal value that corresponds to the binary-weighted sum of all bits

set in the register.

*IDN?

Read the instrument's identification string. This is of the form;

"{manufacturer},{model no.},{serial no.},{software version}"

Note: The serial number field is not used.

*OPC

This command sets the instrument's Operation Complete

Command State active. When any in-progress command is

complete, the state returns to idle and the Operation Complete bit (0)

is set. The command should only be used in conjunction with non-

query commands and is only available for IEEE.

Example

Data logging can take an appreciable time to execute, so it is useful

to program the instrument to generate a service request on

completion of the logging function.

The following command sequence can be used:

*ESR 1 Enables Operation Complete to set the Standard Event

bit.

*SRE 32 Enables Standard Event to trigger service request.

*CLS Clears the Operation Complete bit. INITiate

Initiates data logging. *OPC Sets RQS on completion of

the log

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Options and accessories

Alternatively, the application program may continuously poll the

Operation Complete bit using *ESR?

*OPC?

This command sets the instrument's Operation Complete Query

State active. When any in-progress command is complete, the state

returns to idle, a '1' is placed in the output queue and therefore the

Message Available bit (4) is set.. The command should only be used

in conjunction with non-query commands and is only available for

IEEE.

Example

Data logging can take an appreciable time to execute, so it is useful

to program the instrument to generate a service request on

completion of the logging function.

The following command sequence can be used:

*SRE 16 Enables Message Available bit to trigger a service

request.

*CLS Clears the Message Available bit.

INITiate Initiates data logging. *OPC Sets

RQS on completion of the log

Alternatively, the application programme may continuously poll the

Message Available bit using *STB?

*RST

Clears all pending operations, resets the Operation Complete

Command State and Operation Complete Query State.

*SRE <NRf>

Enable bits in the Service Request Enable Register. The selected

bits are then reported to the Status Byte.

*SRE?

Query the Service Request Enable Register. The instrument returns

a decimal value that corresponds to the binary-weight sum of all bits

set in the register.

Page 7-12

*STB?

Query the Status Byte Summary Register. The instrument returns a

decimal value that corresponds to the binary-weighted sum of all bits

set in the register.

*TRG

Identical to the INITiate command. A

single measurement is made.

*TST?

Always returns '0' to indicate self-test OK.

*WAI

This command is accepted but ignored as all commands are

executed sequentially. It is provided only for compatibility with IEEE-

488.2.

Communications Interface

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Options and accessories

7.6 Measurement Command Group

The measurement command group is used to select channels,

configure channel parameters and acquire readings.

7.6.1 Measurement command summary

Command Description CONFigure:CHANnel: Select the specified channel. CONFigure? Query the channel configuration. CONFigure:TEMPerature:TC Configure a channel for TC measurement. CONFigure:TEMPerature:RTD Configure a channel for RTD measurement.

FETCh? Fetch a single reading. READ? Initiate a measurement and fetch a reading. MEASure:CHANnel?

Select the specified channel. Initiate a measurement and fetch a reading.

MEASure:TEMPerature:TC?

Configure a channel for TC measurement. Initiate a measurement and fetch a reading.

MEASure:TEMPerature:RTD?

Configure a channel for RTD measurement. Initiate a measurement and fetch a reading.

7.6.2 CONFigure Commands

Configure commands are used to select and configure channel

parameters without triggering a measurement.

CONFigure:CHANnel {channel}

Selects the specified channel to be measured (use CONF :TEMP to

configure the measurement parameters).

Only channels that are available can be selected or the command will be

ignored.

{channel} A0, A1, A2, A3, A4

B0, B1, B2, B3, B4

Ch1 - Ch2

Terminates the current measurement cycle and scanning routine. Sets

the trigger mode to single shot. Selects the channel as specified by

the command. Sets the scanner mode to Off. Sets the logging to

memory mode to Off.

Page 7-14

CONFigure?

Used to query the current configuration. The response is an ASCII

string of either of the following forms:

"{channel},TC,{type},{rj mode},{ext rj mode}"

{channel}

A0, A1 , A2, A3, A4 B0, B1 , B2, B3, B4

Ch1-Ch2 {type} B,C,D,E,J,K,N,R,S,T {rj mode} Off, Int, Ext

For rj mode set to Off or Int {ext rj standard}

For rj mode set to Ext {ext rj standard}

(IEC751)

(US/JIS)

(EN60751)

4-23

(User Probe 1-20)

" {channel},RTD,{type},{standard},{con},{current mode},{root 2}"

{channel}

A0, A1 , A2, A3, A4 B0, B1 , B2, B3, B4

Ch1-Ch2 {type} Pt100 {standard} 1

(IEC751)

(US/JIS)

(EN60751)

4-23

(User Probe 1-20)

{con}

3, 4

(3 or 4 wire)

{current mode}

I, -I, AVE

{root 2}

0, 1

0 = off, 1 = on

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Options and accessories

CONFigure:TEMPerature:TC {type},{rj mode},{ext rj standard}

Sets the selected channel for a thermocouple measurement according to

the following parameters.

{type}

B,C,D,E,J,K,N,R,S

{rj mode}

Off, Int, Ext

For rj mode set to Off or

{ext rj standard}

For rj mode set to Ext

{ext rj standard}

(IEC751)

2 (US/JIS) 3 (EN60751) 4-23

(User Probe 1-20)

Note: For {rj mode} set to Off or Int, the {ext rj standard} parameter

must be set to 0 otherwise the command is not recognised.

Terminates the current measurement cycle and scanning routine.

Sets the trigger mode to single shot.

Selects the channel as specified by the command.

Sets the scanner mode to Off.

Sets the logging to memory mode to Off.

CONFigure:TEMPerature:RTD{type},{standard},{con},{current

mode},{root 2}

Sets the selected channel for an RTD measurement according to the

following parameters.

{type} Pt100

{standard}

(IEC751) 2 (US/JIS) 3 (EN60751) 4-23

(User Probe 1-20)

{con}

3, 4

(3 or 4 wire connectivity)

{current mode}

I, -I, AVE

{root 2}

0, 1

0 = off, 1 = on

Terminates the current measurement cycle and scanning routine.

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Sets the trigger mode to single shot.

Selects the channel as specified by the command.

Sets the scanner mode to Off.

Sets the logging to memory mode to Off.

FETCH?

Transfer the last reading stored in the instrument's internal memory

by the INITiate command to the instrument's output buffer. After

reading, the memory is cleared and further FETCh? commands do

not return anything until a fresh INITiate command is sent.

READ?

A measurement is made and the result is sent directly to the output

buffer. The trigger mode is as set using TRIG:MODE command. If in

SINGIe mode, only one reading is taken. If in INFinite mode, readings

continue, with all values sent to the output buffer.

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7.6.3 MEASure Command

These work similar to the CON Figure commands, except that an

immediate measurement is performed with the result being sent to the

output buffer.

MEASure:CHANnel? {channel}

Selects the channel to be measured (use CONF:TEMP to configure the

measurement parameters).

{channel} A0, A1, A2, A3, A4

B0, B1, B2, B3, B4

Ch1 -Ch2

Terminates the current measurement cycle and scanning routine.

Sets the trigger mode to single shot.

Selects the channel as specified by the command.

Sets the scanner mode to Off.

Sets the logging to memory mode to Off.

Initiates a single measurement and fetches a single reading.

MEASure:TEMPerature:TC? {type},{rj mode},{ext rj standard}

Sets the selected channel for a thermocouple measurement

according to the following parameters.

{type} B,C,D,E,J,K,N,R,S,

{rj mode} Off, Int, Ext

For rj mode set to Off or Int

{ext rj standard}

For rj mode set to Ext

{ext rj standard}

(IEC751)

(US/JIS)

(EN60751)

4-23 (User Probe 1-20)

Note: For {rj mode} set to Off or Int, the {ext rj standard}

parameter must be set to 0 otherwise the command is not

recognised.

Options and accessories

Page 7-18

Terminates the current measurement cycle and scanning routine.

Sets the trigger mode to single shot.

Selects the channel as specified by the command.

Sets the scanner mode to Off.

Sets the logging to memory mode to Off.

Initiates a measurement and fetches a single reading.

MEASure:TEMPerature:RTD?{type},{standard},{con},{current

mode},{root 2}

Sets the selected channel for an RTD measurement according to the

following parameters.

{type} Pt100

{standard}

(IEC751)

2 (US/JIS) 3 (EN60751)

4-23

(User Probe 1-20)

{con}

3, 4

(3 or 4 wire connectivity)

{current mode}

I, -I, AVE

{root 2}

0, 1

0 = off, 1 = on

Terminates the current measurement cycle and scanning routine.

Sets the trigger mode to single shot.

Selects the channel as specified by the command.

Sets the scanner mode to Off.

Sets the logging to memory mode to Off.

Initiates a single measurement and fetches a single reading.

Communications Interface

Page 7-19

Options and accessories

7.7 SENSe Command Group

The SENSe command group is used to control the instrument

measurement parameters.

7.7.1 Sense command summary

Command Description SENSe:TEMPerature:UNIT Sets the temperature units to be used. SENSe:TEMPerature:UNIT? Queries the temperature units. SENSe:TEMPerature:RESolution Sets the temperature resolution. SENSe:TEMPerature:RESolution? Queries the temperature resolution. SENSe:ZERO:AUTO Sets the auto-zero measurement mode. SENSeZERO:AUTO? Queries the auto-zero measurement mode.

7.7.2 Sense Commands

SENSe:TEMPerature:UNIT {parameter}

Sets the temperature units to be used in all responses.

{parameter} C Degrees Celsius

F Degrees Fahrenheit

K Degrees Kelvin

SENSe:TEMPerature:UNIT?

Queries the temperature units selection in force.

Returns "C" Degrees Celsius

"F" Degrees Fahrenheit

"K" Degrees Kelvin

SENSe:TEMPerature:RESolution {<resolution>}

Sets the temperature resolution to be used in all responses. The

default resolution at power-up is 0.01.

{resolution} 1, 0.1, 0.01, 0.001

Page 7-20

SENSe:TEMPerature:RESolution?

Queries the temperature resolution.

Returns 1, 0.1, 0.01 or 0.001

SENSe:ZERO:AUTO {mode}

Turns the auto-zero mode on or off. Default at power-up is auto-zero

mode off.

{mode} 1, on Auto-zero on

0, off Auto-zero off

Auto-zero is only available for single channel measurements. The

'on' mode is automatically reset to 'off if any of the following

commands are sent:

CONFigure:TEMPerature:TC {type},{rj mode},{ext rj standard}

CONFigure:TEMPerature:RTD {type},{standard},{con},{current

mode},{root 2}

CONFigure:CHANnel {channel}

MEASure:TEMPerature:TC? {type},{rj mode},{ext rj standard}

MEASure:TEMPerature:RTD? {type},{standard},{con},{current

mode},{root 2}

MEASure:CHANnel? {channel}

ROUTe:SCAN:LSELect {slx}

SENSe:ZERO:AUTO?

Queries the auto-zero mode status.

Returns 1 Auto-zero on

0 Auto-zero off

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Options and accessories

7.8 Mathematical Operation Commands

The CALCulate:AVERage group of commands performs statistical

calculations on the current contents of the data logger memory.

A minimum of two readings must be stored otherwise an "execution

error" is generated i.e. bit (4) of the Standard Event Register is set.

This error is also generated if the log contains inconsistent entries i.e.

readings taken on different channels.

7.8.1 CALCulate:AVERage command summary

Command Description CALCulate:AVERage:MINimum? Queries the minimum stored temperature. CALCulate:AVERage:MAXimum? Queries the maximum stored temperature CALCulate :AVERage:AVERage? Queries the average stored temperature. CALCulate :AVERage:COUNt? Queries the number of stored readings. CALCulate :AVERage:PEAK? Queries the peak to peak value. CALCulate :AVERage:SDEV? Queries the standard deviation value.

7.8.2 CALCulate:AVERage commands

CALCulate :AVERage:MINimum?

Return the minimum temperature value stored in the data log.

CALCulate :AVERage:MAXimum?

Return the maximum temperature value stored in the data log.

CALCulate :AVERage:AVERage?

Return the average of all temperature values stored in the data log.

CALCulate :AVERage:COUNt?

Return the number of readings stored in the data log.

CALCulate :AVERage:PEAK?

Return the peak-to-peak value of the temperature values stored in the

data log i.e. max - min.

CALCulate :AVERage:SDEV?

Return the standard deviation of the temperature values stored in the

data log. This is effectively a measure of RMS noise.

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7.9 Route Command Group

The ROUTe:SCAN commands are used to control the instruments

scanner operation and configure the scanning lists.

The instrument can save up to four independent scanning lists in

none-volatile memory, each scanning list also retains its individually

programmed cycle count, trigger delay time and sample rate.

7.9.1 Route command summary

Command Description ROUTe:SCAN:LSELect Sets the scanner mode and selects a scan list. ROUTe:SCAN:LSELect? Queries the scanner mode and scan list. ROUTe:SCAN:INTernal Configure the specified internal scan list. ROUTe:SCAN:INTernal? Queries the specified internal scan list.

7.9.2 Route commands

ROUTe:SCAN:LSELect <slx>

This command is used to set the scanner mode and select the scan

list, the scanner is enabled by selecting a scanning list.

An empty scanning list can not be selected, the

ROUTe:SCAN:INTernal command should be used to configure the

scanning list.

<slx> SL1, SL2, SL3, SL4 Enable scanner

Select slx scanning list

OFF Disable scanner

Terminates the current measurement cycle and scanning routine.

Sets the Run/Hold trigger mode to Hold when enabling the scanner.

Sets the scanner operation and selects the scanning list as specified

by the command.

ROUTe:SCAN:LSELect?

Queries the state of the scanner and returns the selected scanning

list if enabled.

Returns "SL1", "SL2", "SL3", "SL4" Selected scanning list

"OFF" Scanner disabled

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Options and accessories

ROUTe:SCAN:INTernal <slx>, <scanlist>

This command is used to configure the specified scanning lists for

the internal scanner cards.

<slx> SL1, SL2, SL3, SL4 Select scanning list

<scanlist> A0, A1, A2, A3, A4, Set channel active

B0, B1, B2, B3, B4

To configure a scanning list specify the scanning list number

followed by a list of channels that are required to be active in the list.

Only channels that are available should be specified or the

command will be ignored.

To query a scanning list use the ROUTe:SCAN:INT? <slx>

command.

Configuring a scanning list that is in use will result in the instrument

terminating the current measurement cycle and scanning routine.

Sets the Run/Hold trigger mode to Hold. Sets the scanning list as

specified by the command.

ROUTe:SCAN:INTernal? <slx>

Query the configuration of a scanning list.

The instrument will return a list of selected channels in the specified

scanning list or NONE for an empty scanning list.

<slx> SL1, SL2, SL3, SL4 Select scanning list

Returns "A0, B0, A1, A2, A3, List of active channels

A4, B1, B2, B3, B4"

"NONE" Empty scanning list

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7.10 Trigger Command Group

The TRIGger and SAMPIe commands are used to control the

instruments scanner operation and configure the scanning lists.

7.10.1 Trigger command summary

Command Description

INITiate Initiate a single measurement. ABORt Abort the current measurement. TRIGger:MODE Sets the trigger mode. TRIGger:MODE? Queries the trigger mode. TRIGger:COUNt Sets the specified timer cycle count value. TRIGger:COUNt? Queries specified the timer cycle count value. TRIGger:DELay Sets the specified timer cycle delay value. TRIGger:DELay? Queries the specified timer cycle delay value.

SAMPIe:COUNt? Queries the specified sample count.

SAMPIe:DELay Sets the specified timer sample delay.

SAMPIe:DELay? Queries the specified timer sample delay.

7.10.2 Trigger commands

INITiate

This command is used to Initiate a single measurement without

returning a reading.

The reading is stored internally and is not sent to the output buffer.

The Measurement Available bit (8) of the Operation Condition

Use the FETCh? command to transfer the reading to the output

buffer and clear the Measurement Available bit.

Terminates the current measurement cycle and scanning routine.

Sets the trigger mode to Single shot.

Initiates a single measurement without returning a reading.

Sets the Measurement Available bit (8) of the Operation Condition

ABORt

This command is used to stop the current measurement and clear the

input and output buffers.

Page 7-25

Terminates the current measurement cycle and scanning routine.

Sets the Run/Hold trigger mode to Hold.

TRIGgen:MODE <mode>

This command is used to set the trigger mode to single or infinite.

Setting the trigger mode to single results in a single measurement

being taken when triggered.

Setting the trigger mode to infinite will result in continuous

measurement being taken when triggered.

For IEEE the trigger mode is always forced to single.

If the TRIGger:MODE INF command is sent it will generate a

Command Error and the command will be ignored.

<mode> SINGIe Single shot trigger mode

INFinite Infinite trigger mode (Run/Hold)

Terminates the current measurement cycle and scanning routine.

Sets the trigger mode to the state as defined by the command, when

set to infinite mode the instrument will default to Hold.

TRIGger:MODE?

Query the trigger mode setting.

Returns SING Single shot trigger mode

INF Infinite trigger mode (Run/Hold)

TRIGgen:COUNt <n>

TRIGgen:COUNt <slx>, <n>

The TRIGger:COUNt <n> command is used to set the timer general

cycle count value.

The TRIGger:COUNt <slx>,<n> command is used to set the

individual scanning list timer cycle count values.

<slx> SL1, SL2, SL3, SL4 Specify scan list

<n> 1 to 9999 Specify cycle count value

CONTinuos Cycle count value to continuos

DEFault Cycle count value to continuos

Options and accessories

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Changing a timer cycle count value that is currently in use will result

in the instrument terminating the current measurement cycle and

scanning routine.

Sets the Run/Hold trigger mode to Hold.

Sets the timer cycle count to the value as specified by the

command.

TRIGger:COUNt?

TRIGgen:COUNt? <slx>

TRIGger:COUNt? queries the timer general cycle count value.

TRIGger:COUNt? <slx> queries the specified scanning list timer

cycle count value.

<slx> SL1, SL2, SL3, SL4 Specify scan list

Returns "1" to "9999" Cycle count value

"CONT" Cycle count continuos

TRIGger:DELay <hh:mm:ss>

TRIGgen:DELay <slx>, <hh:mm:ss>

The TRIGger:DELay <hh:mm:ss> command is used to set the

required general timer cycle delay time.

The TRIGger:COUNt <slx>,<hh:mm:ss> command is used to set

the required individual scanning list timer cycle delay time.

<slx> SL1, SL2, SL3, SL4 Specify scan list

<hh:mm :ss> 00:00:00 to 99:59:59 Specify timer delay

Terminates the current measurement cycle and scanning routine.

Sets the Run/Hold trigger mode to Hold.

Sets the required timer delay to the value as specified by the

command.

TRIGger:DELay?

TRIGger:DELay? <slx>

TRIGger:DELay? queries the general timer cycle delay time.

TRIGger:DELay? <slx> queries the specified scanning list timer

cycle delay time.

Page 7-27

Options and accessories

<slx> SL1, SL2, SL3, SL4 Specify scan list

Returns "00:00:00" to "99:59:59" Timer delay hh:mm:ss.

SAMPIe:COUNt?

SAMPIe:COUNt? <slx>

SAMPIe:COUNt? queries the general timer sample count.

The sample count is the same as the general timer sample count.

SAMPIe:COUNt? <slx> queries the specified scanning list sample

count.

The sample count is the product of the timer cycle count and the

number of active channels in the specified scanning list.

<slx> SL1, SL2, SL3, SL4 Specify scan list

Returns 1 to "CONT" Sample count

Note:

If the DATAIogger:MODE is set to On the sample count will be

limited to a maximum of 4000 samples or the amount of available

data logging memory.

SAMPIe:DELay <slx>, <hh:mm:ss>

This command is used to set the specified scanning list timer

sample delay.

<slx> SL1, SL2, SL3, SL4 Specify scan list

<hh:mm:ss> 00:00:00 to 99:59:59 Specify trigger delay

DEFault Trigger delay 00:00:00

Changing a timer sample delay value that is currently in use will

result in the instrument terminating the current measurement cycle

and scanning routine.

Sets the Run/Hold trigger mode to Hold.

Sets the timer sample delay to the value as specified by the

command.

SAMPIe:DELay? <slx>

Query the specified scanning list timer sample delay.

<slx> SL1, SL2, SL3, SL4 Specify scan list Returns

00:00:00 to 99:59:59 Sample delay hh:mm:ss

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7.11 System Related Commands

The SYSTem commands are used to control the instrument none-

measurement global parameters.

7.11.1 System command summary

Command Description

DISPIay:BACKIight Sets the display back light mode.

DISPIay:BACKIight? Queries the display back light mode.

SYSTem:BEEPer Sounds a single beep immediately.

SYSTem:BEEPer:STATe Sets the front panel beeper mode.

SYSTem :BEEPer:STATe? Queries the front panel beeper mode.

SYSTem:TIME Sets the internal clock time.

SYSTem :TIME? Queries the internal clock time.

SYSTem:DATE Sets the internal clock date.

SYSTem :DATE? Queries the internal clock date.

SYSTem:DATE:FORMat Sets the internal clock date format.

SYSTem :DATE:FORMat? Queries the internal clock date format.

7.11.2 System commands

DISPIay:BACKIight {mode}

Turns the front-panel display backlight on or off.

Default at power-up is display backlight on.

{mode} 1, on Display backlight on

0, off Display backlight off

DISPlay:BACKIight?

Query the front-panel display backlight mode setting.

Returns 1 Display backlight on

0 Display backlight off

SYSTem:BEEPer

Issue a single beep immediately.

SYSTem:BEEPer:STATe {mode}

Turns the front-panel beeper on or off. Default at

power-up is front-panel beeper on.

{mode} 1, on Front-panel beeper on

0, off Front-panel beeper off

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SYSTem:BEEPer:STATe?

Query the front-panel beeper mode setting.

Returns 1 Front-panel beeper on

0 Front-panel beeper off

SYSTem:TIME {hh},{mm},{ss}

Set the system calendar/clock time value. The

instrument uses the 24 hour clock format.

{hh},{mm},{ss} 24 hour clock format

SYSTem:TIME?

Query the system calendar/clock time value.

Returns "hh,mm,ss" 24 hour clock format.

SYSTem:DATE:FORMat {format}

Set the system calendar/clock date format for use in date and time

stamping of data logging.

{format} dd:mm:yy

mm:dd:yy

SYSTem:DATE:FORMat?

Query the system calendar/clock date format.

Returns "DD:MM:YY" or "MM:DD:YY'

SYSTem:DATE {format}

Set the system calendar/clock date value.

{format} {dd},{mm},{yy} or [mm],[dd],[yy]

SYSTem:DATE?

Query the system calendar/clock date value.

Returns "dd,mm,yy" or "mm,dd,yy"

Options and accessories

Page 7-30

Communications Interface

7.12 DATAIogger Command Group

This group of commands stores and retrieves measurement values

using the data logging memory. This memory is non-volatile and can

store up to 4000 readings.

7.12.1 Datalogger command summary

Command Description

DATAIogger:MODE Sets the data logger mode.

DATAIogger:MODE? Queries the data logger mode.

DATAIogger:CLEAr Clears the data logger memory.

DATAIogger:STARt Start logging readings to data log memory.

DATAIogger:STOP Stop logging readings to data log memory.

DATAIogger:STEP Single step logging readings to data log memory.

DATAIogger:VALUe?

Request a specified number of readings from data log

memory.

DATAIogger:POINts? Queries the number of readings stored in the data log memory.

7.12.2 Datalogger commands

DATAIogger:MODE {mode}

Turns data logging to memory on or off.

{mode} 1, on Data logger on

0, off Data logger off

Terminates the current measurement cycle.

Sets the Run/Hold trigger mode to Hold.

Sets the logging to memory mode as specified by the command.

Re-sets the scanner routine if the scanner mode is On.

DATAIogger:MODE?

Query the state of the data logger mode setting.

Returns "ON" Data logger on

"OFF" Data logger off

DATAIogger:CLEAr

Clears the data logger memory.

CAUTION: All the current stored data will be lost!

Terminates the current measurement cycle.

Clears the data logger memory.

Re-sets the sample and data logger counter.

Re-sets the scanner routine if the scanner mode is On.

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DATAIogger:STARt

The DATAIogger:STARt command like the READ? command is

used to Initiate single or multiple readings the readings are sent to

the data logger memory but not to the output buffer.

DATAIogger:STARt command is only active when

DATAIogger:MODE is ON.

If the data logger memory is full, any further DATAIogger:STARt

commands will generate an "execution error" the command will be

ignored.

Terminates the current measurement cycle.

Initiates a single or multiple measurement and stores the result in

the data logger memory.

Re-sets the scanner routine to the beginning and starts the next

cycle if the scanner mode is On.

DATAIogger:STOP

The DATAIogger:STOP command performs the same function as

the ABORt command, terminating the current measurement cycle

and clearing the input and output buffers.

DATAIogger:STOP command is only active when

DATAIogger:MODE is ON.

DATAIogger:STARt or DATAIogger:STEP commands can be

used to continue the logger from this point.

Terminates the current measurement cycle.

Sets the Run/Hold trigger mode to Hold.

DATAIogger:STEP

The DATAIogger:STEP command is used to Initiate a single

measurement and stores the result in the next location of the data

logger memory.

DATAIogger:STEP command is only active when

DATAIogger:MODE is ON.

The command can be used to single step through a scanner routine

saving the results in the data logger memory.

Options and accessories

Page 7-32

Isotech TTI-7-R Operator's Handbook Manual

Specifications and Main Features

Frequently Asked Questions

User Manual