Data Translation DT8871, DT8874, DT8871U, DT8872, DT8873 User Manual

Title Page

UM-23652-AA

User’s Manual for
Standard TEMPpoint, VOLTpoint,
and MEASURpoint LXI
Instruments

DT8871, DT8871U, DT8872, DT8873, DT8874

Copyright Page

Notice

Measurement Computing Corporation does not authorize any Measurement Computing
Corporation product for use in life support systems and/or devices without prior written consent
from Measurement Computing Corporation. Life support devices/systems are devices or systems
that, a) are intended for surgical implantation into the body, or b) support or sustain life and whose
failure to perform can be reasonably expected to result in injury. Measurement Computing
Corporation products are not designed with the components required, and are not subject to the
testing required to ensure a level of reliability suitable for the treatment and diagnosis of people.

Trademark and Copyright Information

Measurement Computing Corporation, InstaCal, Universal Library, and the Measurement
Computing logo are either trademarks or registered trademarks of Measurement Computing
Corporation. Refer to the Copyrights & Trademarks section on mccdaq.com/legal for more
information about Measurement Computing trademarks.

Other product and company names mentioned herein are trademarks or trade names of their
respective companies.

© 2018 Measurement Computing Corporation. All rights reserved. No part of this publication
may be reproduced, stored in a retrieval system, or transmitted, in any form by any means,
electronic, mechanical, by photocopying, recording, or otherwise without the prior written
permission of Measurement Computing Corporation.

Radio and Television Interference

This equipment has been tested and found to comply with CISPR EN55011 Class A and
EN61326-1 requirements and also with the limits for a Class A digital device, pursuant to Part
15 of the FCC Rules. These limits are designed to provide reasonable protection against
harmful interference when the equipment is operated in a commercial environment. This
equipment generates, uses, and can radiate radio frequency energy and, if not installed and
used in accordance with the instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to cause harmful
interference, in which case the user will be required to correct the interference at his own
expense.

Changes or modifications to this equipment not expressly approved by Data Translation could
void your authority to operate the equipment under Part 15 of the FCC Rules.

Note: This product was verified to meet FCC requirements under test conditions that
included use of shielded cables and connectors between system components. It is important
that you use shielded cables and connectors to reduce the possibility of causing interference
to radio, television, and other electronic devices.

FCC Page

Canadian Department of Communications Statement

This digital apparatus does not exceed the Class A limits for radio noise emissions from
digital apparatus set out in the Radio Interference Regulations of the Canadian Department of
Communications.

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de la class A prescrites dans le Règlement sur le
brouillage radioélectrique édicté par le Ministère des Communications du Canada.

Table of Contents

Table of Contents

About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Intended Audience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

How this Manual is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Conventions Used in this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Where To Get Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Chapter 1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

TEMPpoint Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

VOLTpoint Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

MEASURpoint Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Getting Started Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Part 1: Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Chapter 2: Preparing to Use the

Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Checking the System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Installing the Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Prerequisite Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Installation Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Viewing the Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Chapter 3: Setting Up and Installing

the Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Connecting the Instrument to the LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Connecting to a Site LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Connecting to a Private LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Connecting Using a Hub or Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Connecting Directly to a Computer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Applying Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Getting an IP Address and Host Name. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Determining Ethernet Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Resetting the Instrument. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Chapter 4: Wiring Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

General Wiring Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

5

Contents

Warm-Up Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Connecting Thermocouple Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Connecting RTD Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

4-Wire RTD Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

3-Wire RTD Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

2-Wire RTD Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Connecting Voltage Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Connecting Voltage Inputs to Thermocouple Channels . . . . . . . . . . . . . . . . . . . . . . . . . 55

Connecting Voltage Inputs to RTD Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Connecting Voltage Inputs to Voltage Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Connecting Current Loop Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Connecting Current Loop Inputs to Thermocouple Channels. . . . . . . . . . . . . . . . . . . . 60

Connecting Current Loop Inputs to RTD Channels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Connecting Current Loop Inputs to Voltage Channels . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Connecting Digital I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Connecting Digital Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Connecting Digital Output Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Chapter 5: Configuring the Instrument

Using the Web Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Before Using the Web Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Java Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Internet Explorer Browser Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

JavaScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Security Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Internet Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Local Intranet Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Trusted Sites Zone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Pop-up Blockers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Associating CSV Files with Microsoft Excel

or Notepad . . . . . . . . . . . . . . . . . . . . . . . . 74

Locating Your Instrument on the LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Running the Eureka Discovery Utility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Configuring Windows Firewall Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Launching the Web Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Configuring the Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

LAN Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Channel Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Scan Rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Filter Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Alarm Limits Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Digital Input and Trigger Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Digital Output Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

6

Measuring Data and Controlling the Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Starting and Stopping a Scan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Controlling the Digital Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Reading the Digital Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Downloading Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Part 2: Using Your

Instrument. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Chapter 6: Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Block Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

DT8871U Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

DT8871 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

DT8872 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

DT8873 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

DT8874 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Analog Input Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Analog Input Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Thermocouple Input Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Cold Junction Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Open Thermocouple Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

RTD Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Input Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Out of Range Data for Thermocouple Channels . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Out of Range Data for RTD Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Out of Range Data for Voltage Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Sample Clock Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Trigger Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Conversion Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

Simultaneous Single-Value Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

Continuous Scan Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

Specifying Analog Input Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

How Continuous Scan Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

Filtering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Data Format for Thermocouple Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Data Format for RTD Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Data Format for Voltage Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Contents

7

Contents

Digital Input Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Digital Output Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Channel-to-Channel Functional Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Operation Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Chapter 7: Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

General Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

If Your Instrument Needs Factory Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Appendix A: Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Basic Instrument Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Thermocouple Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

System Temperature Error for the DT8871U and DT8874 . . . . . . . . . . . . . . . . . . . . . . 124

System Temperature Error for the DT8871 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

RTD Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Temperature Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Voltage Measurement Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Isolation and Protection Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Memory Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Digital I/O Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Power, Physical, and Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Regulatory Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Connector Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Thermocouple Connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

RTD Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Voltage Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Ethernet (RJ45) Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

External Power Supply Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Appendix B: Connector Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Appendix C: Configuring Network Settings on

Your PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Configuring the PC to Use Auto-IP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Specifying a Static IP Address for your Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

Reconfiguring the PC to Use a Static IP Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

8

About this Manual

TEMPpoint is a family of temperature measurement instruments that includes the DT9871,
DT9871U, DT8871, DT8871U, DT9872, and DT8872. This manual describes the DT8871,
DT8871U, and DT8872 Ethernet LXI (LAN eXtensions for Instrumentation) models.

VOLTpoint is a family of voltage measurement instruments that includes the DT9873 and
DT8873. This manual describes the DT8873 LXI model.

MEASURpoint™ a family of mixed temperature and voltage measurement instruments that
includes the DT9874 and DT8874. This manual describes the DT8874 LXI model.

Note: For information on the DT9871, DT9871U, DT9872, DT9873, and DT9874 USB models
of TEMPpoint, VOLTpoint, and MEASURpoint, refer to the User’s Manual for Standard
TEMPpoint, VOLTpoint, and MEASURpoint USB Instruments.

The first part of this manual describes how to install and set up your instrument, and verify
that the instrument is working properly.

The second part of this manual describes the features and capabilities of your instrument
using the IVI-COM instrument driver software. Troubleshooting information is also provided.

Note: If you are programming the instrument using the IVI-COM driver, refer to the
DtxMeasurement IVI-COM driver online help for more information.

If you are using Standard Commands for Programmable Instruments (SCPI) to program your
instrument, refer to the SCPI Programmer’s Manual for MEASURpoint for more information.

Intended Audience

This document is intended for engineers, scientists, technicians, or others responsible for
using and/or programming a TEMPpoint, VOLTpoint, or MEASURpoint instrument. It is
assumed that you have some familiarity with thermocouples, RTDs, and/or voltages and that
you understand your application.

9

About this Manual

How this Manual is Organized

This manual is organized as follows:

• Chapter 1, “Overview,” summarizes the major features of the TEMPpoint, VOLTpoint,
and MEASURpoint instruments, as well as the supported software and accessories.

• Chapter 2, “Preparing to Use the Instrument,” describes how to unpack the instrument,
check the system requirements, install the software, and view the documentation online.

• Chapter 3, “Setting Up and Installing the Instrument,” describes how to apply power to
the instrument and connect the instrument to the network.

• Chapter 4, “Wiring Signals,” describes how to wire signals to the instrument.

• Chapter 5, “Configuring the Instrument Using the Web Interface,” describes how to
configure the instrument using the instrument’s web interface.

• Chapter 6, “Principles of Operation,” describes the analog input and digital I/O features
of the TEMPpoint, VOLTpoint, and MEASURpoint instruments in detail.

• Chapter 7, “Troubleshooting,” provides information that you can use to resolve problems
with your instrument, should they occur.

• Appendix A, “Specifications,” lists the specifications of the TEMPpoint, VOLTpoint, and
MEASURpoint instruments.

• Appendix B, “Connector Pin Assignments,” describes the pin assignments of the digital
I/O connector on the TEMPpoint, VOLTpoint, and MEASURpoint instruments.

• Appendix C, “Configuring Network Settings on Your PC,” describes how to configure the
network settings of your PC to use Auto-IP or a static IP address.

• An index completes this manual.

Conventions Used in this Manual

The following conventions are used in this manual:

• Notes provide useful information or information that requires special emphasis, cautions
provide information to help you avoid losing data or damaging your equipment, and
warnings provide information to help you avoid catastrophic damage to yourself or your
equipment.

• Items that you select or type are shown in bold.

• CAUTION – This icon denotes a caution, which advises you to consult the
documentation where this symbol is marked.

CAUTION – Do not operate this product in a manner not specified in this document.
Product misuse can result in a hazard. You can compromise the safety protection built into
the product if the product is damaged in any way.

10

Related Information

Refer to the following documents for more information on using a TEMPpoint, VOLTpoint, or
MEASURpoint LXI instrument:

• DtxMeasurement IVI-COM Driver online help. This document describes how to use the
IVI-COM driver to access the capabilities of your instrument.

The IVI-COM driver works with any development environment that supports COM
programming, including MATLAB® from The MathWorks
or Visual Basic®.NET, Agilent® VEE Pro, National Instruments™ LabVIEW™ or
LabWindows™, and so on.

• QuickDAQ User’s Manual (UM-25242). This manual describes how to create a QuickDAQ
application to acquire and analyze data from a TEMPpoint, VOLTpoint, or MEASURpoint
instrument.

• SCPI Programmer’s Manual for LXI Measurement Instruments. For programmers who want
to use the SCPI interface to program a TEMPpoint, VOLTpoint, or MEASURpoint
instrument, this document describes the supported SCPI commands and example
programs for these instruments.

• IVI foundation (www.ivifoundation.org)

About this Manual

TM

, Microsoft® Visual C#®.NET

• Omega Complete Temperature Measurement Handbook and Encyclopedia® or the Omega
Engineering web site: http://www.omega.com. Both resources provide valuable information on

thermocouple types, RTD types, standards, and linearization.

Where To Get Help

Should you run into problems installing or using a TEMPpoint, VOLTpoint, or MEASURpoint
instrument, the Data Translation Technical Support Department is available to provide
technical assistance. Refer to Chapter 7 for more information. If you are outside the United
States or Canada, call your local distributor, whose number is listed on our web site
(www.mccdaq.com).

11

About this Manual

12

1

Overview

Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Getting Started Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

13

Chapter 1

Hardware Features

Data Translation provides a number of LXI (Ethernet) instruments to meet your measurement
needs, including the following:

• TEMPpoint – a family of temperature measurement instruments

• VOLTpoint – a family of voltage measurement instruments

• MEASURpoint – a family of mixed temperature and voltage measurement instruments

All of these Ethernet instruments are class C devices that comply with LXI version 1.1.

The following sections summarize the features of the TEMPpoint, VOLTpoint, and
MEASURpoint LXI instruments.

TEMPpoint Features

TEMPpoint instruments include the following models: DT8871U, DT8871, and DT8872.

Figure 1 shows a DT8871U instrument.

14

Figure 1: TEMPpoint Instrument

The key features of TEMPpoint instruments are as follows:

• DT8871U and DT8871:

 Configurable analog input channels for thermocouple or differential voltage inputs;

easy-access jacks for each channel for quick wiring

 One CJC (cold junction compensation) input for each thermocouple channel

 B, E, J, K, N, R, S, and T thermocouple types supported; the instrument automatically

linearizes the measurements and returns the data as a 32-bit, floating-point
temperature values

 Input range of ±0.075 V for the DT8871U (with 0.25 V RMS A/D noise using no

software filtering) and

±1.25 V for the DT8871 (with 5 V RMS A/D noise using no

software filtering)

 Break-detection circuitry to detect open thermocouple inputs

• DT8872:

 Configurable analog input channels for RTDs and differential voltage inputs;

easy-access jacks for each channel for quick wiring

 100 , 500 , and 1000  platinum RTD types supported using alpha curves of 0.00385

(European) or 0.00392 (American)

 4-wire, 3-wire, or 2-wire configurations; the DT8872 automatically linearizes the

measurements and returns the data as 32-bit, floating-point temperature, resistance, or
voltage values

 Input range of ±1.25 V

• One 24-bit, Delta-Sigma A/D converter per channel for simultaneous, high-resolution
measurements

Overview

• Throughput rate of up to 10 Samples/s for all channels.

• Software or external, digital trigger on digital input line 0 starts acquisition

• Auto-calibrating front-end resets the zero point on each power-up; in addition, the
instrument supports anytime calibration, performing an auto-calibration function on
software command

• Measurement Instrument Calibration Utility allows you to calibrate the instrument in the
field (see page 21 for more information on this utility)

• 8 opto-isolated digital input lines; you can read the digital input port through the analog
input data stream for correlating analog and digital measurements

• 8 opto-isolated digital output lines; the outputs are solid-state relays that operate from
±30 V at currents up to 400 mA (peak) AC or DC

15

Chapter 1

VOLTpoint Features

Figure 2 shows a VOLTpoint instrument.

Figure 2: VOLTpoint Instrument

The key features of VOLTpoint (DT8873) instruments are as follows:

• Direct connection of analog input channels for differential voltage inputs; removable
screw terminal blocks for each channel for quick wiring

• One 24-bit, Delta-Sigma A/D converter per channel for simultaneous, high-resolution
measurements

• Software-selectable input range of ±10 V or ±60 V per channel (note that for the ±60 V
range, no more than 30 Vrms, 42.4 Vpk, 60 VDC is allowed)

• Throughput rate of up to 10 Samples/s for all channels

• Software or external, digital trigger on digital input line 0 starts acquisition

• Auto-calibrating front-end resets the zero point on each power-up; in addition, the
instrument supports anytime calibration, performing an auto-calibration function on
software command

• Measurement Instrument Calibration Utility allows you to calibrate the instrument in the
field (see page 21 for more information on this utility)

• 8 opto-isolated digital input lines; you can read the digital input port through the analog
input data stream for correlating analog and digital measurements

16

• 8 opto-isolated digital output lines; the outputs are solid-state relays that operate from
±30 V at currents up to 400 mA (peak) AC or DC

MEASURpoint Features

The standard MEASURpoint (DT8874) instrument provides 16 thermocouple channels, 16
RTD channels, and 16 voltage channels. Figure 3 shows a MEASURpoint instrument.

Overview

Figure 3: MEASURpoint Instrument

The key features of MEASURpoint (DT8874) instruments are as follows:

• Analog Input Channels 0 to 15:

 Configurable channels for thermocouple or differential voltage inputs; easy-access

jacks for each channel for quick wiring

 One CJC (cold junction compensation) input for each thermocouple channel

 B, E, J, K, N, R, S, and T thermocouple types supported; the instrument automatically

linearizes the measurements and returns the data as a 32-bit, floating-point
temperature values

 Input range of ±0.075 V (with 0.25 V RMS A/D noise using no software filtering)

 Break-detection circuitry to detect open thermocouple inputs

17

Chapter 1

• Analog Input Channels 16 to 31:

 Configurable analog input channels for RTDs and differential voltage inputs;

easy-access jacks for each channel for quick wiring

 100 , 500 , and 1000  platinum RTD types supported using alpha curves of 0.00385

(European) or 0.00392 (American)

 4-wire, 3-wire, or 2-wire configurations; the DT8872 automatically linearizes the

measurements and returns the data as 32-bit, floating-point temperature, resistance, or
voltage values

 Input range of ±1.25 V

• Analog Input Channels 31 to 48:

 Direct connection of analog input channels for differential voltage inputs; removable

screw terminal blocks for each channel for quick wiring

 Software-selectable input range of ±10 V or ±60 V per channel (note that for the ±60 V

range, no more than 30 Vrms, 42.4 Vpk, 60 VDC is allowed)

• One 24-bit, Delta-Sigma A/D converter per channel for simultaneous, high-resolution
measurements

• 30 VAC, 60 VDC continuous functional isolation ch-ch and ch-gnd, verified by a 500 Vpk
withstand

• Throughput rate of up to 10 Samples/s for all channels

• Software or external, digital trigger on digital input line 0 starts acquisition

• Auto-calibrating front-end resets the zero point on each power-up; in addition, the
instrument supports anytime calibration, performing an auto-calibration function on
software command

• Measurement Instrument Calibration Utility allows you to calibrate the instrument in the
field (see page 21 for more information on this utility)

• 8 opto-isolated digital input lines; you can read the digital input port through the analog
input data stream for correlating analog and digital measurements

• 8 opto-isolated digital output lines; the outputs are solid-state relays that operate from
±30 V at currents up to 400 mA (peak) AC or DC

18

Supported Software

The following software is available for use with the TEMPpoint, VOLTpoint, and
MEASURpoint instruments:

• Eureka Discovery Utility – This utility helps you locate or "discover" all LXI (Ethernet)
instruments that are connected to your system and provides the following information
about your instrument: the IP address, manufacturer, model number, serial number, and
version of the firmware that is running on your instrument. In addition, you can use this
utility to configure Windows firewall settings and update the firmware for your Data
Translation LXI instrument.

• Instrument Web Interface – This built-in interface, described in Chapter 5, allows you to
verify the operation of your instrument and perform basic functions with Internet
Explorer and no additional software. Using it, you can configure your instrument, control
output signals, measure input signals, and save results to disk.

• QuickDAQ Base Version – The base version of QuickDAQ is free-of-charge and allows
you to acquire and analyze data from all Data Translation USB and Ethernet devices,
except the DT9841 Series, DT9817, DT9835, and DT9853/54. Using the base version of
QuickDAQ, you can perform the following functions:

 Discover and select your devices.

Overview

 Configure all input channel settings for the attached sensors.

 Load/save multiple hardware configurations.

 Generate output stimuli (fixed waveforms, swept sine waves, or noise signals).

 On each supported data acquisition device, acquire data from all channels supported

in the input channel list.

 Choose to acquire data continuously or for a specified duration.

 Choose software or triggered acquisition.

 Log acquired data to disk in an .hpf file.

 Display acquired data during acquisition in either a digital display using the Channel

Display window or as a waveform in the Channel Plot window.

 Choose linear or logarithmic scaling for the horizontal and vertical axes.

 View statistics about the acquired data, including the minimum, maximum, delta, and

mean values and the standard deviation in the Statistics window.

 Export time data to a .csv or .txt file; you can open the recorded data in Microsoft

Excel® for further analysis.

 Read a previously recorded .hpf data file.

 Customize many aspects of the acquisition, display, and recording functions to suit

your needs, including the acquisition duration, sampling frequency, trigger settings,
filter type, and temperature units to use.

19

Chapter 1

• QuickDAQ FFT Analysis Option – When enabled with a purchased license key, the
QuickDAQ FFT Analysis option includes all the features of the QuickDAQ Base version
plus basic FFT analysis features, including the following:

 The ability to switch between the Data Logger time-based interface and the FFT

Analyzer block/average-based interface.

 Supports software, freerun, or triggered acquisition with accept and reject controls for

impact testing applications.

 Allows you to perform single-channel FFT (Fast Fourier Transform) operations,

including AutoSpectrum, Spectrum, and Power Spectral Density, on the acquired
analog input data. You can configure a number of parameters for the FFT, including
the FFT size, windowing type, averaging type, integration type, and so on.

 Allows you to display frequency-domain data as amplitude or phase.

 Supports dB or linear scaling with RMS (root mean squared), peak, and peak-to-peak

scaling options

 Supports linear or exponential averaging with RMS, vector, and peak hold averaging

options.

 Supports windowed time channels.

 Supports the following response window types: Hanning, Hamming, Bartlett,

Blackman, Blackman Harris, and Flat top.

 Supports the ability to lock the waveform output to the analysis frame time.

 Allows you to configure and view dynamic performance statistics, including the input

below full-scale (IBF), total harmonic distortion (THD), spurious free dynamic range
(SFDR), signal-to-noise and distortion ratio (SINAD), signal-to-noise ratio (SNR), and
the effective number of bits (ENOB), for selected time-domain channels in the Statistics
window.

 Supports digital IIR (infinite impulse response) filters.

• QuickDAQ Advanced FFT Analysis Option – When enabled with a purchased software
license, the QuickDAQ Advanced FFT Analysis option includes all the features of the
QuickDAQ Base version with the FFT Analysis option plus advanced FFT analysis
features, including the following:

 Allows you to designate a channel as a Reference or Response channel.

 Allows you to perform two-channel FFT analysis functions, including Frequency

Response Functions (Inertance, Mobility, Compliance, Apparent Mass, Impedance,
Dynamic Stiffness, or custom FRF) with H1, H2, or H3 estimator types,
Cross-Spectrum, Cross Power Spectral Density, Coherence, and Coherent Output
Power.

 Supports the Exponential response window type.

20

 Supports the following reference window types: Hanning, Hamming, Bartlett,

Blackman, Blackman Harris, FlatTop, Exponential, Force, and Cosine Taper windows.

 Supports real, imaginary, and Nyquist display functions.

 Allows you to save data in the .uff file format.

• DtxMeasurement IVI-COM driver – This driver provides access to the instrument’s
functions through a COM server. The IVI-COM driver works in any 32- or 64-bit
development environment that supports COM programming, including MATLAB, Visual
Basic.NET, Visual C#.NET, Agilent VEE Pro, LabVIEW, LabWindows, and others.

• SCPI commands – Use SCPI commands to program TEMPpoint, VOLTpoint, or
MEASURpoint LXI instruments. Refer to the SCPI Programmer’s Manual for LXI
Measurement Instruments for information on the supported SCPI commands and example
programs.

• Measurement Instrument Calibration Utility – Users can calibrate a TEMPpoint,
VOLTpoint, or MEASURpoint instrument in the field using precise calibration equipment
and the Measurement Instrument Calibration Utility. Since each instrument consists of up
to 48 individual channels, great care must be taken to ensure that proper warm-up times
are followed and precise calibration equipment is used.

The calibration utility ships with a comprehensive help file that describes the required
equipment and calibration procedure, including warm-up times, for each instrument.

The calibration utility allows you to revert to the factory calibration for any or all
channels, or revert back to the last user calibration values, if desired. In addition, this
utility generates a report that lists the starting and ending calibration values for each
channel, allowing traceability.

Overview

Refer to the Data Translation web site (www.mccdaq.com) for information about selecting the
right software package for your needs.

21

Chapter 1

Accessories

The following optional accessories are available for TEMPpoint, VOLTpoint, or
MEASURpoint instruments:

• STP37 screw terminal panel – The STP37, shown in Figure 4, permits easy screw terminal
connections for accessing the digital I/O signals of a TEMPpoint, VOLTpoint, or
MEASURpoint instrument.

Figure 4: STP37 Screw Terminal Panel

• EP333 cable–The EP333, shown in Figure 5, is a 2-meter shielded cable with two 37-pin
connectors that connects the STP37 screw terminal panel to the digital I/O connector of
the instrument.

Figure 5: EP333 Cable

• EP373 Single Rack-mount Kit – Mounts one TEMPpoint, VOLTpoint, or MEASURpoint
instrument in a rack.

• EP374 Dual Rack-mount Kit – Mounts two TEMPpoint, VOLTpoint, or MEASURpoint
instruments side-by-side in a rack.

22

Getting Started Procedure

Set Up and Install the Instrument

(see Chapter 3 starting on page 33)

Wire Signals

(see Chapter 4 starting on page 45)

Verify the Operation of the Instrument

(see Chapter 5 starting on page 67)

Prepare to Use the Instrument

(see Chapter 2 starting on page 27)

The flow diagram shown in Figure 6 illustrates the steps needed to get started using a
TEMPpoint, VOLTpoint, or MEASURpoint instrument. This diagram is repeated in each
Getting Started chapter; the shaded area in the diagram shows you where you are in the
getting started procedure.

Overview

Figure 6: Getting Started Flow Diagram

23

Chapter 1

24

Part 1: Getting Started

2

Preparing to Use the

Instrument

Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Checking the System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Installing the Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Viewing the Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

27

Chapter 2

Set Up and Install the Instrument

(see Chapter 3 starting on page 33)

Wire Signals

(see Chapter 4 starting on page 45)

Configuring the Instrument Using the Web

Interface (see Chapter 5 starting on page 67)

Prepare to Use the Instrument

(this chapter)

28

Unpacking

Open the shipping box and verify that the following items are present:

• TEMPpoint, VOLTpoint, or MEASURpoint instrument

• EP372 Ethernet cable

• EP361 +5V power supply and cable

• For DT8872, DT8873, and DT8874 instruments, a bag of pluggable screw terminable
blocks.

If an item is missing or damaged, contact Data Translation. If you are in the United States, call
the Customer Service Department at 508-946-5100. An application engineer will guide you
through the appropriate steps for replacing missing or damaged items. If you are located
outside the United States, call your local distributor, listed on Data Translation’s web site
(www.mccdaq.com).

Preparing to Use the Instrument

29

Chapter 2

Checking the System Requirements

For reliable operation, ensure that your computer meets the following system requirements:

• Processor: Pentium 4/M or equivalent

•RAM: 1 GB

• Screen Resolution: 1024 x 768 pixels

• Disk Space: 4 GB

•Ethernet port

• Administrator privileges for software installation

• For access to the instrument web interface:

 Java Version 6, Update 5 or greater

 Internet Explorer 6.0 or 7.0 web browser

Refer to page 69 for more information on installing Java and configuring your browser
settings

• Acrobat Reader 5.0 or later for viewing documentation

30

Installing the Software

This section describes how to install the software you need to use your TEMPpoint,
VOLTpoint, or MEASURpoint instrument.

Prerequisite Software

No prerequisite software is required if you are using a single client to access a TEMPpoint,
VOLTpoint, or MEASURpoint instrument on the LXI bus, or if you are managing how
multiple clients concurrently access the instrument on the LXI bus. (In these case, your
application can use sockets to communicate with the instrument.)

If, however, you want multiple clients to access your instrument on the LXI bus, and you want
to "lock" access to the instrument so that one client cannot change the configuration of the
instrument that another client is accessing, you need to install VISA; we recommend either
Agilent VISA or NI-VISA from National Instruments. You can then use the VISA methods
viLock/viUnlock to prevent other clients from accessing the instrument.

To install Agilent VISA, do the following:

Preparing to Use the Instrument

1. Go to www.agilent.com, enter IO Libraries Suite in the search field, and select Agilent

IO Libraries Suite 15.0 from the search results.

2. Follow the instructions on Agilent’s web site to download and install the Agilent IO

Libraries, which include VISA support, VISA COM support, and the Agilent Connection
Expert tool.

We recommend that you run Data Translation’s Eureka Discovery Utility that is provided with
the MEASURpoint software to locate your LXI instrument on the network (see page 75 for
more information).

Installation Instructions

Install the software for your instrument from the web at
http://mccdaq.com/downloads/DTSoftware/MEASURpoint.

The installation program guides you through the installation process.

31

Chapter 2

Viewing the Documentation

Note: To view the documentation, you must have Adobe Reader 5.0 or greater installed on
your system.

You can access the documentation for your instrument from the Windows Start menu as
follows:

• For documentation about the TEMPpoint, VOLTpoint, or MEASURpoint instrument, click

Programs -> Data Translation, Inc -> Hardware Documentation -> User’s Manual for
Standard TEMPoint, VOLTpoint, and MEASURpoint LXI Instruments.

• For documentation on the Eureka Discovery Utility, click Programs -> Data Translation,
Inc -> Instrument Support -> Eureka LXI Instrument Discovery.

• For documentation on the QuickDAQ application, click Programs -> Data Translation,
Inc -> QuickDAQ -> QuickDAQ User’s Manual

• For documentation on the DtxMeasurement IVI-COM driver, click Programs -> Data
Translation, Inc -> DtxMeasurement -> DtxMeasurement IVI Driver 1.1.8
Documentation.

• For documentation about SCPI support, click Programs -> Data Translation, Inc ->
Measurement SCPI Support ->SCPI Programmer’s Manual for Measurement.

The following may be helpful when using Adobe Reader:

• To navigate to a specific section of the document, click a heading from the table of contents
on the left side of the document.

• Within the document, click the text shown in blue to jump to the appropriate reference
(the pointer changes from a hand to an index finger).

• To go back to the page from which the jump was made, click the right mouse button and
Go Back, or from the main menu, click Document, and then Go Back.

• To increase or decrease the size of the displayed document, from the main menu, click
View, and then Zoom.

• By default, Adobe Reader smooths text and monochrome images, sometimes resulting in
blurry images. If you wish, you can turn smoothing off by clicking File, and then
Preferences/General, and unchecking Smooth Text and Images.

32

3

Setting Up and Installing

the Instrument

Connecting the Instrument to the LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Applying Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Getting an IP Address and Host Name. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Determining Ethernet Activity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Resetting the Instrument. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

33

Chapter 3

Set Up and Install the Instrument

(this chapter)

Wire Signals

(see Chapter 4 starting on page 45)

Prepare to Use the Instrument

(see Chapter 2 starting on page 27)

Configuring the Instrument Using the Web

Interface (see Chapter 5 starting on page 67)

Note: Your TEMPpoint, VOLTpoint, and MEASURpoint instruments are factory-calibrated.
Thereafter, yearly recalibration is recommended. Refer to page 106 for more information on
calibration.

34

Connecting the Instrument to the LAN

LAN

Connector

Figure 7 shows the LAN (RJ45) connector on the rear of the instrument that is used to connect

your instrument to the LAN (Local Area Network).

Setting Up and Installing the Instrument

Figure 7: LAN Connector on the Rear of the Instrument

This section describes how to connect your instrument to the LAN. Two connection schemes
are shown:

• Site LAN connections, described on page 36

• Private LAN connections, described on page 37

Note: It is recommended that you consult with your network administrator to ensure that
all network security, performance, and reliability issues are considered when using
connecting instruments to the LAN.

35

Chapter 3

Computer

Ethernet

Hub/ Switch/ Router

TEMPpoint,

VOLTpoint, or

MEASURpoint

+5 V Power

Supply

+5 V Power

Supply

+5 V Power

Supply

+5 V Power

Supply

To S i t e LAN

TEMPpoint,

VOLTpoint, or

MEASURpoint

TEMPpoint,

VOLTpoint, or

MEASURpoint

TEMPpoint,

VOLTpoint, or

MEASURpoint

Connecting to a Site LAN

A site LAN is useful in applications that require access by many users or access by users at
distributed sites. In this connection scheme, a DHCP (Dynamic Host Configuration Protocol)
server is used to assign an IP address to the instrument.

Figure 8 shows a typical site LAN connections using a dedicated Ethernet hub, switch, or

router. Figure 9 shows typical site LAN connections without using a dedicated Ethernet hub,
switch, or router.

Note: Use standard LAN cables for network connections. TEMPpoint, VOLTpoint, and
MEASURpoint instruments ship with a standard LAN cable (EP372) for connecting to the
LAN (RJ45) connector on the rear panel of the instrument.

36

Figure 8: Typical Site LAN Connections using a Hub, Switch, or Router

Setting Up and Installing the Instrument

Computer

+5 V Power

Supply

To S i t e LAN

To Site L A N

TEMPpoint,

VOLTpoint, or

MEASURpoint

Figure 9: Typical Site LAN Connections Without Using a Hub, Switch, or Router

Connecting to a Private LAN

A private LAN (or subnet) generally involves the direct connection of the instruments to the
computer, and may include Ethernet hubs or switches. Access to the instruments is limited to
users that are directly connected to the private LAN; therefore, security, performance, and
reliably are generally better on a private LAN than on a site LAN.

In this connection scheme, the DHCP (Dynamic Host Configuration Protocol) server is
typically not available; therefore, Auto-IP is used to assign an IP address to the instrument.

Note: If no DHCP server exists and your PC is set up to use a static IP address, you must
temporarily reconfigure your PC to use Auto-IP, as described on Appendix C starting on

page 145.

Connecting Using a Hub or Switch

Figure 10 shows a typical connection scheme when connecting TEMPpoint, VOLTpoint, or

MEASURpoint instruments to a private LAN using a dedicated Ethernet hub or switch.

Note: Use standard LAN cables for network connections. The instrument ships with a
standard LAN cable (EP372) for connecting to the LAN (RJ45) connector on the rear panel of
the instrument.

37

Chapter 3

Computer

Ethernet

Hub/ Switch

+5 V Power

Supply

+5 V Power

Supply

+5 V Power

Supply

+5 V Power

Supply

TEMPpoint,

VOLTpoint, or

MEASURpoint

TEMPpoint,

VOLTpoint, or

MEASURpoint

TEMPpoint,

VOLTpoint, or

MEASURpoint

TEMPpoint,
VOLTpoint, or
MEASURpoint

Computer

+5 V Power

Supply

Standard LAN Cable (if PC enabled Auto-MDIX)

or

Ethernet Crossover Cable (if PC doesn’t enable

Auto-MDIX or you are not sure)

TEMPpoint,
VOLTpoint, or
MEASURpoint

Figure 10: Typical Private LAN Connections using a Hub or Switch

Connecting Directly to a Computer

Optionally, you can connect the TEMPpoint, VOLTpoint, or MEASURpoint instrument
directly to your computer, creating an ad hoc network, as shown in Figure 11. Be aware that
the time and date settings of the instrument will not be updated using this connection method.
Therefore, this connection scheme is generally recommended for quick set up and verification
only.

Note: TEMPpoint, VOLTpoint, and MEASURpoint instruments do not support the
Auto-MDIX function; therefore, use a crossover cable rather than a standard LAN cable to
connect your instrument unless your computer has enabled the Auto-MDIX function.

Figure 11: Typical Private LAN Connections when Connecting Directly to a Computer

38

Applying Power

EP361 +5 V

Power Supply

Power

Switch

TEMPpoint, VOLTpoint, and MEASURpoint instruments are shipped with an EP361 +5V
power supply and cable. To apply power to the instrument, do the following:

1. Connect the +5 V power supply to the power connector on the rear panel of the
instrument. Refer to Figure 12.

Setting Up and Installing the Instrument

Figure 12: Attaching a +5 V Power Supply to the Instrument

2. Plug the power supply into a wall outlet.

Note: For proper grounding of your measurement instrument, ensure that you use the

power supply and cable (EP361) that is provided with the instrument and that you use all
three prongs of the cable when connecting it to your wall outlet.

3. Press the Power switch on the rear panel of the instrument, shown in Figure 12, to turn on
the instrument.

The Power LED on the front panel lights to indicate that power is on.

39

Chapter 3

Power L ED LAN LED

Figure 13 shows the location of the LEDs on the front panel of the instrument; a

MEASURpoint instrument is shown in this example.

Figure 13: LEDs on the Front Panel of the Instrument

40

Getting an IP Address and Host Name

Once your instrument is connected to the LAN and powered on, the instrument automatically
requests an Ethernet address from a DHCP (Dynamic Host Configuration Protocol) server, if
available, and a host name from a DNS (Dynamic Domain Name Service) server, if available.

If these services are not available on the LAN, the instrument uses Auto-IP to set up its
TCP/IP configuration. In this case, the IP address is in the range of 169.254.0.0 to

169.254.255.255 with a subnet mask of 255.255.0.0.

Note: If no DHCP server exists and your PC is set up to use a static IP address, you must
temporarily reconfigure your PC to use Auto-IP, then configure your instrument to use a
static IP address, as described in Appendix C starting on page 145.

You can use the instrument’s web interface, described in Chapter 5 starting on page 67, to see
the IP address and host name that is assigned to your instrument.

Setting Up and Installing the Instrument

Notes: When programming a TEMPpoint, VOLTpoint, or MEASURpoint instrument, you
access the instrument through its address string, which consists of an IP address or host
name, such as TCPIP0::192.43.218.69::inst0::INSTR or TCPIP0::192.43.218.69::SOCKET. If a
host name was returned by the DNS server, you can also address the instrument using its
host name, such as TCPIP0::arrakis.datx.com::inst0::INSTR.

For IVI-COM programmers, you can also assign a VISA alias to the instrument. For example,
rather than addressing the instrument as TCPIP0::192.43.218.69::inst0::INSTR, you can a
VISA alias, such as TEMPpoint1, instead. See your VISA documentation for more
information on VISA resource strings and creating VISA aliases.

41

Chapter 3

USB LED (not used on this instrument)
LMT LED
OPN LED

ENet Link

LED

ENet Activity

LED

Reset Pin

Determining Ethernet Activity

You can use the ENet Link and ENet Activity LEDs on the rear of the instrument, shown in

Figure 14, with the LAN LED on the front of the instrument, shown in Figure 13, to determine

the Ethernet activity on your instrument. Tab le 1 describes the meaning of these LEDs.

Figure 14: Rear Panel of the Instrument

Table 1: Using LEDs to Determine Ethernet Activity

LEDs Color Description

LAN LED
(on front panel)

Solid Green Instrument has valid IP address.

Blinking Green Instrument identified using the Web interface; see page 75

Red If the Ethernet link is operational, the instrument does not

for more information.

have a valid IP address.

Otherwise, the Ethernet link is not operational.

42

Table 1: Using LEDs to Determine Ethernet Activity (cont.)

LEDs Color Description

Setting Up and Installing the Instrument

ENet Link LED
(on rear panel)

ENet Activity LED
(on rear panel)

Yellow Ethernet link operational.

Off Ethernet link not operational.

Green Network traffic detected.

Off No network traffic detected.

43

Chapter 3

Resetting the Instrument

If needed, you can restore the default configuration of your instrument by pressing the Reset
pin on the rear panel of the instrument, shown in Figure 14 on page 42, until the LAN LED on
the front panel turns off (which takes approximately 5 seconds), and then releasing the Reset
pin.

The instrument reboots automatically using the factory-default LAN configuration (DHCP
and auto-IP enabled); this process typically takes up to 40 seconds to complete. This forces the
instrument to re-acquire an IP address from the DHCP server, or if that fails, to use Auto-IP to
get an IP address.

Note: The default configuration overwrites any changes that you have made to the LAN
configuration (IP address and password) using the instrument’s web interface. Refer to page

79 for information on the default values that are used when the instrument is reset.

The calibration parameters are not affected by the reset.

44

4

Wiring Signals

General Wiring Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Warm - Up Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Connecting Thermocouple Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Connecting RTD Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Connecting Voltage Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Connecting Current Loop Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Connecting Digital I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

45

Chapter 4

Set Up and Install the Instrument

(see Chapter 3 starting on page 33)

Wire Signals

(this chapter)

Configuring the Instrument Using the Web

Interface (see Chapter 5 starting on page 67)

Prepare to Use the Instrument

(see Chapter 2 starting on page 27)

46

General Wiring Recommendations

Keep the following recommendations in mind when wiring signals to a TEMPpoint,
VOLTpoint, or MEASURpoint instrument:

• Separate power and signal lines by using physically different wiring paths or conduits.

• To avoid noise, do not locate the instrument and cabling next to sources that produce high

electromagnetic fields, such as large electric motors, power lines, solenoids, and electric
arcs, unless the signals are enclosed in a mumetal shield.

• Locate the instrument’s front panel as far away as possible from sources of high or low

temperatures or strong air currents, such as fans.

• Prevent electrostatic discharge to the I/O while the instrument is operational.

• When wiring thermocouples, select an appropriate wire length and gauge for each

thermocouple; in general, use the shortest wire length and largest gauge for the
application to yield best results.

• Use shielded wire for maximum rejection of electrical interference.

Wiring Signals

47

Chapter 4

Warm-Up Time

For accurate thermocouple measurements, MEASURpoint instruments require a warm-up
time of 1 hour for the analog circuitry to stabilize.

For accurate RTD measurements, ensure that your RTD sensors and external calibration
resistors warm up for 1 minute after the MEASURpoint instrument has been warmed up for 1
hour.

48

Connecting Thermocouple Inputs

The DT8871U, DT8871, and DT8874 instruments contain thermocouple jacks for connecting
thermocouple inputs.

Note: On the standard DT8874 instrument, channels 0 to 15 correspond to the thermocouple
input channels.

Internally, these signals are connected in differential mode. You can mix and match the
following thermocouple types across channels: B, E, J, K, N, R, S, and/or T.

Each thermocouple input jack is polarized and accepts a mating plug in the appropriate
orientation. Tabl e 2 lists the color designations for the + and – polarities of the supported
thermocouple types for both the ANSI (American) and IEC (International) standards.

Table 2: Thermocouple Color Designation Standards

Wiring Signals

Thermocouple

Standard

ANSI Type J White Red

IEC Type J Black White

Thermocouple

Type

Type K Yellow Red

Type T Blue Red

Type E Violet Red

Type S Black Red

Type R Black Red

Type B Gray Red

Type N Orange Red

Type K Green White

Type T Brown White

Type E Violet White

Type S Orange White

Type R Orange White

Wire Color Coding

+ Polarity

Wire Color Coding

– Polarity

Type B Gray White

Type N Pink White

For more information on thermocouple standards, refer to the following web site:

http://www.omega.com/thermocouples.html.

49

Chapter 4

Thermocouple

Channels

Thermocouple Input

–

+

–

+

Omega Plug (SMPW)

CAUTION:

When connecting inputs to the thermocouple connectors on a
MEASURpoint or TEMPpoint instrument, it is highly recommended
that you use only original Omega thermocouple plugs (SMPW), as
connectors from other suppliers may not be equivalent mechanically.
Refer to page 138 for more information on the connectors.

If you use connectors from suppliers other than Omega, there is a
risk that you may mechanically damage the thermocouple
connectors on the MEASURpoint or TEMPpoint instrument.

Figure 15 shows how to connect a thermocouple input to a thermocouple channel.

50

Figure 15: Connecting Thermocouple Inputs

Connecting RTD Inputs

RTD

Channels

1

Current

3

– Sense2+Sense

4

Return

Each DT8872 and DT8874 contains pluggable screw terminals for connecting RTD inputs.
Internally, these signals are connected in differential mode.

Note: On the standard DT8874 instrument, channels 16 to 31 correspond to the RTD input
channels.

Figure 16 shows the numbering of the screw terminal blocks for RTD connections.

Wiring Signals

Figure 16: Screw Terminal Block Numbering for RTD Connections

51

Chapter 4

RTD Channel

RTD

425 A
Current

– Sense +Sense

Return

1243

R

L

R

L

R

L

R

L

The DT8872 supplies each RTD channel with 425 A of excitation current to prevent
self-heating. The resistance of the RTD circuit increases gradually, repeatably, and linearly
with temperature. As the resistance increases, the voltage drop across the RTD also increases.
The DT8872 reads this voltage drop and automatically converts the voltage to the appropriate
temperature based on the RTD type.

The DT8872 and DT8874 support Pt100 (100  Platinum), Pt500 (500  Platinum), and Pt1000
(1000  Platinum) RTD types using Alpha coefficients of 0.00385 and 0.00392; you can mix and
match RTD types across RTD channels. Refer to the following web site for more information
on RTD types: http://www.omega.com.

To connect an RTD input, you can use a 4-wire, 3-wire, or 2-wire connection scheme, described
in the following subsections. For the best accuracy, use 4-wire RTD connections; this
connection scheme enables Kelvin sensing to minimize errors due to lead wire resistance.

4-Wire RTD Connections

The 4-wire configuration offers the best accuracy with long connection wires, compared to the
3- and 2-wire configurations. The 4-wire connection scheme eliminates errors due to lead wire
resistance (R
is automatically cancelled as long as the sense wires are connected.

) and thermal heating. Wire impedance of up to 100  anywhere in the hookup

L

Figure 17 shows a 4-wire RTD connection.

Figure 17: 4-Wire RTD Connection

52

3-Wire RTD Connections

RTD Channel

RTD

425 A

Current

– Sense +Sense

Return

R

L

1243

*RL is lead wire resistance.

The 3-wire configuration eliminates one wire from the 4-wire RTD connection. Lead wire
resistance (R
drop is essentially equal and opposite to the voltage drop across +Sense.

Figure 18 shows a 3-wire RTD connection.

) errors in the return wire from –Sense may be introduced unless the voltage

L

Wiring Signals

Figure 18: 3-Wire RTD Connection

2-Wire RTD Connections

The 2-wire configuration is the least accurate of the RTD wiring configurations because the
lead wire resistance (R
measurement errors, particularly if the lead wire is long. If you decide to use the 2-wire
connection scheme, ensure that you use short lead wire connections.

For example, if the lead resistance is 0.5  in each wire, the lead resistance adds a 1  of error
to the resistance measurement. Using a 100  RTD (Pt100) with a 0.00385/°C European curve
coefficient, the resistance represents an initial error of 1  /(0.385 /°C) or 2.6°C. Since the
lead wire resistance changes with ambient temperature, additional errors are also introduced
in the measurement.

) and its variation with temperature contribute significant

L

53

Chapter 4

RTD Channel

RTD

425 A
Current

– Sense +Sense

Return

R

L

R

L

1243

Figure 19 shows a 2-wire RTD connection.

Figure 19: 2-Wire RTD Connection

54

Connecting Voltage Inputs

The way you connect voltage inputs depends on the channel type you are using. This section
describes how to connect voltage inputs to thermocouple input channels, RTD input channels,
and voltage input channels.

Connecting Voltage Inputs to Thermocouple Channels

Figure 20 shows how to connect a differential voltage input to a thermocouple input channel

on the DT8871U, DT8871, or DT8874 instrument.

Note: On the standard DT8874 instrument, channels 0 to 15 correspond to the thermocouple
input channels.

Wiring Signals

55

Chapter 4

Voltage Input

–

+

Omega Plug (SMPW-U-M)

Analog Input 0Analog Input 0

Return

Signal Source

+–

Thermocouple

Channels

56

Figure 20: Connecting Voltage Inputs to a Thermocouple Channel

Connecting Voltage Inputs to RTD Channels

Vin +Vin –

RTD Channel

– Sense +Sense

1243

Shield

Figure 21 shows how to connect a voltage input to an RTD channel on a DT8872 or DT8874

instrument.

Note: On the standard DT8874 instrument, channels 16 to 31 correspond to the RTD input
channels.

Wiring Signals

Figure 21: Connecting Voltage Inputs to an RTD Channel

The input impedance is well over 100 M using the voltage –Sense and +Sense inputs.

For best accuracy when connecting voltage inputs, use twisted-pair wires with a dead-ended
shield connected to pin 4 of the screw terminal block.

57

Chapter 4

Voltage Input

Channels

1

+Sense

3

–Sense2No

Connect

4

Shield

Connecting Voltage Inputs to Voltage Channels

Each DT8873 and DT8874 contains pluggable screw terminals for connecting voltage inputs.

Note: On the standard DT8874 instrument, channels 32 to 47 correspond to the voltage input
channels.

Figure 22 shows the numbering of the screw terminal blocks for voltage connections.

58

Figure 22: Screw Terminal Block Numbering for Voltage Connections

Figure 23 shows how to connect voltage inputs to the DT8873 and DT8874.

Vin +Vin –

Voltage Channel

– Sense +Sense

1243

Shield

*Pin 2 is no connect

Figure 23: Connecting Voltage Inputs

Wiring Signals

The input impedance is well over 100 M using the voltage –Sense and +Sense inputs.

Note: For best accuracy when connecting voltage inputs, use twisted-pair wires with a
dead-ended shield connected to pin 4 of the screw terminal block.

59

Chapter 4

Connecting Current Loop Inputs

In some applications, such as solar cell, fuel cell, and car battery testing applications, you may
want to accurately sense and measure current in a high voltage loop.

TEMPpoint, VOLTpoint, and MEASURpoint instruments provide channel-to-channel
functional isolation of 60 VDC maximum continuous working voltage, meaning that each
input can be referenced to 60 VDC maximum, with a 500 Vpk withstand rating, verified by a
5 s dielectric withstand test.

The way you connect current loop inputs depends on the channel type you are using. This
section describes how to connect current loop inputs to thermocouple input channels, RTD
input channels, and voltage input channels.

Connecting Current Loop Inputs to Thermocouple Channels

Thermocouple input channels on the DT8871U and DT8874 have an input range of ±0.075 V.
Therefore, you can use a 1  series resistor to measure ±0.075 A. Similarly, you can use a 0.1 
series resistor to measure ±0.75 A.

Thermocouple input channels on the DT8871 have an input range of ±1.25 V. Therefore, you
can use a 1  series resistor to measure ±1.25 A. Similarly, you can use a 0.1  series resistor to
measure ±12.5 A or a 10  series resistor to measure ±0.125 A.

Figure 24 shows how to wire your signals to measure a current loop. In this example, the input

is referenced to ±60 V.

Note: On the standard DT8874 instrument, channels 0 to 15 correspond to the thermocouple
input channels.

60

Wiring Signals

1 series resistor

60 V

Circuit+

+

–

+

–

Use a 1

 series resistor to convert current to voltage.

For thermocouple channels on the DT8871U and DT8874, 1

= 0.075 A = 0.075 V.

For thermocouple channels on the DT8871, 1

= 1.25 A = 1.25 V.

Thermocouple

Channels

Figure 24: Connecting Current Loop Inputs to Thermocouple Channels

61

Chapter 4

1 shunt resistor

Use a 1

 shunt resistor to convert current to voltage: 1 = 1.25 A = 1.25 V.

60 V

Circuit+

+

–

RTD Channel

– Sense +Sense

1243

Shield

Connecting Current Loop Inputs to RTD Channels

RTD channels on the DT8872 and DT8874 instruments have an input range of ±1.25 V.
Therefore, you can use a 1  shunt resistor to measure ±1.25 A. Similarly, you can use a 0.1 
shunt resistor to measure ±12.5 A or a 10  shunt resistor to measure ±0.125 A.

Figure 25 shows how to wire your signals to measure a current loop. In this example, the input

is referenced to ±60 V.

Note: On the standard DT8874 instrument, channels 16 to 31 correspond to the RTD input
channels.

62

Figure 25: Connecting Current Loop Inputs to RTD Channels

Connecting Current Loop Inputs to Voltage Channels

250 

shunt resistor

28 V (can be up to ±60 V)

±20 mA

Load

+

–

Voltage Channel

– Sense +Sense

1243

Shield

In this example, the input range is ±10 V.

Voltage input channels on the DT8873 and DT8874 instruments have an input range of ±10 V
or ±60 V. You select the input range for each channel using software.

With the 24-bit A/D converter, high current, high side current shunts can be used for
resolutions of less than 0.01 A on a 100 A range.

Typi c al Sh unts :

• Vishay WSMS5515

.2 mV

• Vishay CSM2512S

10 mV

• Deltec MUB-500-50

.1 mV

Notes: On the DT8874 instrument, channels 32 to 47 correspond to the voltage input
channels.

Wiring Signals

Figure 26 shows an example of wiring signals to measure ±20 mA using the ±10 V input

range.

Figure 26: Connecting a Current Loop Input to a Voltage Channel to Measure ±20 mA

63

Chapter 4

EP333 Cable

STP37 Screw Terminal Panel

Digital I/O

Connector

Connecting Digital I/O Signals

To make digital I/O connections easier, you can use the optional STP37 screw terminal panel
and EP333 cable with your TEMPpoint, VOLTpoint, or MEASURpoint instrument. Connect
the STP37 to the digital I/O connector of the instrument as shown in Figure 27:

Figure 27: Connecting the Instrument to the STP37

Figure 28 shows the layout of the STP37 screw terminal panel and lists the assignments of

each screw terminal.

64

Wiring Signals

J1

2

21

3

22

4

23

5

24

6

25

7

26

8

27

9

28

36

17

35

16

34

15

33

14

32

13

31

12

30

11

29

10

120181937

TB2

TB4

TB3

TB5

TB1

Digital Input 1+

Digital Output 7

Digital Input 1



Digital Input 2+

Digital Input 2



Digital Input 3+

Digital Input 3



Digital Input 4+

Digital Input 4



Digital Input 5+

Digital Input 5



Digital Input 6+

Digital Input 6



Digital Input 7+

Digital Input 7



Not Connected

Not Connected

Digital Output 7

Digital Output 6

Digital Output 6

Digital Output 5

Digital Output 5

Digital Output 4

Digital Output 4

Digital Output 3

Digital Output 3

Digital Output 2

Digital Output 2

Digital Output 1

Digital Output 1

Digital Output 0

Digital Output 0

Digital Input 0+

Digital Input 0

Not Connected

Not Connected

Not Connected

DIN 0 +

DIN 1 +

TTL Outputs

Instrument

Digital I/O Connector

DIN 0 –

DIN 1 –

1 k*

+5 V*

*1 k pull-up to +5 V required for TTL outputs.

pin 21

pin 1

pin 20

pin 2

Figure 28: STP37 Screw Terminal Panel

Connecting Digital Input Signals

Figure 29 shows how to connect digital input signals (lines 0 and 1, in this case) to the digital

I/O connector on the TEMPpoint, VOLTpoint, or MEASURpoint instrument.

Figure 29: Connecting Digital Inputs

65

Chapter 4

Digital Out 0

Digital Out 0pin 10

120 V AC

or 240 V AC

Relay

Motor

10 A

Fuse

NeutralHot

30V DC @ 400 mA

+ *

–

pin 29

Instrument

Digital I/O Connector

*Output can switch AC or DC.

Controlled by

Software

Note: Relay, motor, and circuits must be properly rated. Reinforced isolation must be

maintained between the digital output circuits and the relay/motor

switching circuits.

Connecting Digital Output Signals

The digital output lines of a TEMPpoint, VOLTpoint, or MEASURpoint instrument act as
solid-state relays. The customer-supplied signal can be ±30 V at up to 400 mA (peak) AC or
DC.

You can use the digital output lines of the instrument to control solid-state or mechanical
relays or high-current electric motors. Figure 30 shows how to connect digital output signals
to line 0 of the instrument to control a motor relay.

Figure 30: Switching up to 30 V at 400 mA

66

5

Configuring the Instrument

Using the Web Interface

Before Using the Web Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Locating Your Instrument on the LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Configuring the Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Measuring Data and Controlling the Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Downloading Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

67

Chapter 5

Set Up and Install the Instrument

(see Chapter 3 starting on page 33)

Wire Signals

(see Chapter 4 starting on page 45)

Configure the Instrument Using the Web

Interface (this chapter)

Prepare to Use the Instrument

(see Chapter 2 starting on page 27)

You can configure the operation of your instrument either locally or remotely using the
instrument’s web interface.

If your browser supports Java, you can also verify the operation of your instrument using the
web interface.

The QuickDAQ application that is provided as part of the MEASURpoint software also allows
you to verify the operation of your instrument and does not require Java for operation;
therefore, if your browser does not support Java, use QuickDAQ instead. Refer to the
documentation provided with QuickDAQ for more information.

This chapter focuses on configuring your instrument using the web interface.

Note: DT8871, DT8871U, DT8872, and DT8873 instruments with firmware version 2.2.3.1 or
greater are identified in firmware as DT8874-xxT-xxR-xxV, where xxT specifies the number of
thermocouple channels, xxR specifies the number of RTD channels, and xxV specifies the
number of voltage input channels.

68

Before Using the Web Interface

This section describes system requirements and browser settings for proper operation of the
instrument’s web interface.

Note: At any instant, up to 8 clients can access the instrument concurrently using the web
interface.

Up to 12 additional clients can access the instrument concurrently using SCPI commands
over VISA or sockets. Of these, 4 can be VXI-11 clients, which use the ::SOCKETS or
VISA::INSTR resource to access the instrument.

At this time, the web and SCPI interfaces cannot be "locked;" therefore, one client can change
the configuration of the instrument that another client is accessing. However, you can
optionally lock the VXI-11 interface using the VISA APIs viLock/viUnlock; this prevents
other VXI-11 clients (including VXI-11 discovery) from accessing the instrument. Refer to the
SCPI documentation for your instrument for more information on supported SCPI
commands.

Configuring the Instrument Using the Web Interface

Java Requirements

To verify the operation of your instrument through the web interface, your browser must
support Version 6, Update 5 or greater of Java. If your browser does not support Java, you can
still configure your instrument through the web interface; however, you must use QuickDAQ
to verify the operation of your instrument in this case.

You can verify Java versions and settings by accessing the Java Control Panel, select Windows
Start -> Control Panel and open the Java dialog. To download or upgrade Java, go to
www.java.com.

Internet Explorer Browser Settings

If you have an older version of Internet explorer that supports Java, configure your browser as
follows; otherwise, skip this section:

• JavaScript (Active Scripting) must be enabled

• Security level of the instrument’s IP address must be Medium-high or lower

• Pop-up blockers must be disabled

The following sections describe how to configure these settings.

69

Chapter 5

JavaScript

To enable JavaScript (also referred to as Active Scripting), perform the following steps:

1. From the Internet Explorer browser, select To ol s -> Internet Options.

2. Click the Security tab.

3. Select Internet, and then click Custom Level.

4. Scroll down to the Scripting section.

5. Under Active Scripting, select Enable, and then click OK.

Security Levels

By default, the IP address of the instrument is added to the Internet zone. If you'd rather leave
the settings of the Internet zone at a level higher than Medium-high, then you can add the IP
address of the instrument to either the Local intranet or Trusted sites zone and configure the
security level of that zone to Medium-high or lower.

The following section describe how to configure each zone.

Internet Zone

To configure the security level of the instrument module’s IP address in the Internet zone,
perform the following steps:

1. From the Internet Explorer browser, select To ol s -> Internet Options.

2. Click the Security tab.

70

Configuring the Instrument Using the Web Interface

3. Select Internet and move the slide bar to select a security level of Medium-high or lower.

4. Click OK.

Local Intranet Zone

To add the IP address of the instrument to the Local intranet zone and configure its security
level, do the following:

1. From the Internet Explorer browser, select To ol s -> Internet Options.

2. Click the Security tab.

3. Click Local intranet, and click Sites.

4. Select which web sites to add to the zone, and then click Advanced.

5. Enter the IP address of the instrument to the zone, and click Add.

71

Chapter 5

6. Click Close.

7. Move the slide bar to select a security level of Medium-high or lower.

8. Click OK.

Trusted Sites Zone

To add the instrument’s IP address to the Trusted sites zone and configure its security level,
do the following:

To add the IP address of the instrument to the Trusted sites zone and configure its security
level, do the following:

1. From the Internet Explorer browser, select To ol s -> Internet Options.

2. Click the Security tab.

3. Click Tru st ed s it es , and click Sites.

4. Enter the IP address of the instrument to the zone (note that the address must be prefaced

by (https://), and click Add.

72

Configuring the Instrument Using the Web Interface

5. Click Close.

6. Move the slide bar to select a security level of Medium-high or lower.

7. Click OK.

Pop-up Blockers

To disable pop-up blockers, perform the following steps:

1. From the Internet Explorer browser, select To ol s ->Pop-up Blocker.

2. Select Turn Off Pop-up Blocker.

73

Chapter 5

Associating CSV Files with Microsoft Excel or Notepad

Note: This section applies only if your browser supports Java. If your browser does not
support Java, downloading data to a file through the web interface is not supported.

If files with the .CSV extension do not have the proper file associations/actions set up, then
clicking Download in the Download Measurements page of the instrument web interface will
not present the option of saving the data to a file or loading the data to an application, such as
Microsoft Excel
displayed in the browser.

The following steps describe how to associate a CSV file with Microsoft Excel or Notepad in
Windows XP; refer to the documentation for your operating system for more information:

1. From the Windows Control Panel, open the Folder Options dialog, and select File Types.

2. Scroll down to the CSV entry and select it. (If it is not in the list add it as a new file type by

selecting New and entering CSV).

®

or Microsoft

®

Notepad, that can display it. Instead, the data will be

3. Click Advanced to access the Edit File Type dialog box.

4. Click New to access the New Action dialog box.

5. Enter Open in the Action: edit field.

6. Click Browse and find Excel.exe (typically located in C:\Program Files\Microsoft

Office\OFFICExx\EXCEL.EXE) or Notepad.exe (typically located in
C:\Windows\Notepad.exe) on your system, and then click OK.

74

7. Click OK.

Now when you click Download on the Download Measurements web page, you should see a
dialog box asking if you want to Open or Save the data in the appropriate application.

Configuring the Instrument Using the Web Interface

Locating Your Instrument on the LAN

To access the web interface of your instrument, you must determine its IP address on your
TCP/IP network.

Note: Discovery works only for devices on the same subnet.

We recommend that you run Data Translation’s Eureka Discovery Utility that is provided with
the instrument to locate your instrument on the network quickly. Alternatively, you can use
other LXI discovery tools, such as Agilent Connection Expert, if you have them installed on
your computer. Or you can check your router’s address assignments or locate the instrument’s
MAC (Ethernet hardware) address in your DHCP server log.

Running the Eureka Discovery Utility

To use the Eureka Discovery Utility, from the Windows Start menu, click Programs -> Data
Translation, Inc -> Instrument Support -> Eureka LXI Instrument Discovery.

A screen similar to the one shown in Figure 31 appears.

Figure 31: Eureka LXI Discovery Utility

If you are having trouble seeing your instrument in this list, check your Windows firewall
settings using the information in the next section; otherwise, skip this section and continue
with “Launching the Web Interface” on page 78.

75

Chapter 5

Configuring Windows Firewall Settings

If you are having trouble seeing your instrument using the Eureka Discovery Utility, check
your Windows firewall settings by doing the following:

1. Right click in the tile bar of the Eureka Discovery Utility.

The following menu options appear:

2. Click the Firewall Configuration... option.

The following window appears:

76

Configuring the Instrument Using the Web Interface

3. On the left side of the window, select Turn Windows Firewall on or off, select Tur n O n
Windows Firewall setting for proper operation of the Eureka Discovery Utility, and click
OK.

4. On the left side of the window, select Allow a program or feature through Windows
Firewall, ensure that Eureka LXI Instrument Discovery is included in the list of
exceptions, and click OK.

5. If Eureka LXI Instrument Discovery is not included in the exception list, add the utility to

the list of exceptions by doing the following:

a. Click Allow another program...

b. Browse to C:\Program Files\Data Translation\Instrument Support\Eureka.exe,

and click Open.

The Eureka LXI Instrument Discovery utility appears in the window.

c. Click Add to add the utility to the list of exceptions.

d. Click OK to exit from the Windows Firewall Configuration menu.

77

Chapter 5

Launching the Web Interface

From the Eureka utility, double-click the appropriate IP address to open the web pages for
your instrument using your default web browser. Alternatively, you can enter the IP address
of your instrument directly in your Internet Explorer address bar to see the instrument’s web
interface.

The main web page, similar to the following screen, shows information about your instrument
on the network:

78

Note: If your browser does not support Java, the Measurement & control -> Acquisition
and Measurement & control -> Digital input pages of the web interface are not supported.
To acquire and view input data, use the QuickDAQ application instead.

If you have multiple instruments connected to the network, you can click "Turn ON front
panel identification indicator" to light the LAN LED on the instrument, described on page 40,
to indicate the device you are using.

To change the description, IP address, or time source associated with the instrument, click the

Modify

links to navigate to the LAN Configuration page, described on page 79.

Configuring the Instrument

Web pages are provided for configuring the following aspects of your instrument:

• Local Area Network (LAN) settings

• Channels that you want to measure

•Scan rate

•Filter

•Alarm limits

• Digital I/O lines

LAN Configuration

Use the Configuration -> LAN web page to configure the Local Area Network (LAN) settings
for the instrument. A screen similar to the following appears:

Configuring the Instrument Using the Web Interface

When you first access your instrument, the LAN settings that the instrument obtained
through DHCP or AutoIP should be sufficient. If you need to make changes later, click the
Modify button to enable changes. Contact your system administrator and view the
instrument’s built-in help pages to determine the correct LAN settings.

79

Chapter 5

Note: If you want to assign a static IP address, ensure that you uncheck the checkbox called
Automatic private IP address enabled.

When you click Modify, you must supply a password for the instrument.

The username is admin; it cannot be changed. The default password is admin. You can change
the password on this page.

Note that the new password is saved in permanent memory in the instrument and goes into
effect after the instrument reboots. If you are prompted for a password before the instrument
reboots, you must enter your original password. The web interface, IVI-COM driver, and SCPI
interface use the same password. You can also configure the password using the IVI-COM
driver or through SCPI commands.

You are prompted for this password any time the instrument’s configuration is changed or
when an attempt is made to start or stop a scan. This mechanism relies on features in the
HTTP standard to prevent unauthorized users from reconfiguring or operating the
instrument. Note, however, that authentication is not required to view the instrument’s
configuration or scan results.

Note: The DT8871, DT8871U, DT8872, DT8873, and DT8874 instruments with firmware
version 2.2.3.1 or greater use the default user name admin and the default password admin.
Firmware version 2.2.3.1 and greater support password-protected commands. Therefore, you
must enter the appropriate password to change the instrument’s configuration or to start and
stop a scan.

If the firmware version for these instruments is less than 2.2.3.1, then the default user name is
sysadmin and the default password is user. Firmware versions less than 2.2.3.1 do not
support password-protected commands. Therefore, you are not prompted to enter a
password to change the instrument’s configuration or to start or stop a scan.

Specify the time zone that is used by the instrument as an offset (either + or –) from GMT
(Greenwich Mean Time). The specified hour and minute is added to the UTC (Coordinated
Universal Time)
minutes sets the current time zone used by the instrument to five hours and 0 minutes behind
GMT.

time that is maintained by the instrument. For example choosing –5 hours, 0

Channel Configuration

Use the Configuration -> Channel web page to enable the channels that you want to measure,
specify the sensor to use for each channel, and add a label to describe each channel, if desired.
A screen similar to the following appears:

80

Configuring the Instrument Using the Web Interface

To change your channel configuration, do the following:

1. Under Enable Channel, check the boxes next to the channels that you want to collect data.
You can use the Enable All and Disable All buttons for quick configuration of many
channels.

2. Under Type , select the sensor type for each configured channel from the drop-down list
boxes. If all the channels are of the same type (thermocouple, RTD, or voltage), you can
use the Set all button to change all channels to the sensor type specified in the heading’s
drop-down list box.

3. Describe the channels, if desired, by entering text in the Label field corresponding to the
channel that you want to describe.

4. Click Save configuration to apply your changes. If you do not save before leaving this
page, your changes are lost.

You c a n als o clic k the Discard changes button (before you save) to return to the previous
configuration, if desired.

81

Chapter 5

Scan Rate

Use the Configuration -> Scan Rate web page to set the scan rate for all channels on the
instrument. A screen similar to the following appears:

To change your instrument’s scan rate, do the following:

1. Type a value, in Hertz, between the minimum and maximum shown in the Scan Rate
field.

Note: The scan rate that you specify is rounded to the closest "correct" value that the
instrument can accept without error. Internally, the 10 Hz clock is divided by an integer in
the range of 1 to 65535 (the internal clock divider) to determine the closest value. When
you save the scan rate configuration, the actual scan rate is shown.

2. Click Save configuration to apply your changes. If you do not save before leaving this
page, your changes are lost.

You c a n als o clic k the Discard changes button (before you save) to return to the previous
configuration, if desired.

82

Filter Configuration

Use the Configuration -> Filter web page to configure the filter type used by the instrument.
A screen similar to the following appears:

Configuring the Instrument Using the Web Interface

You can choose one of the following filter types:

• Raw – No filter. Provides fast response times, but the data may be difficult to interpret.

Use when you want to filter the data yourself.

The Raw filter type returns the data exactly as it comes out of the Delta-Sigma A/D
converters. Note that Delta-Sigma converters provide substantial digital filtering above
the Nyquist frequency.

Generally, the only time it is desirable to use the Raw filter setting is if you are using fast
responding thermocouples, sampling them at higher speeds (> 1 Hz), and need as much
response speed as possible.

• Moving average – (The default filter setting.) Provides a compromise of filter

functionality and response time. This filter can be used in any application.

This low-pass filter takes the previous 16 samples, adds them together, and divides by 16.

83

Chapter 5

Alarm Limits Configuration

Use the Configuration -> Limits web page to define alarm conditions for specific enabled
channels that you want to measure. A screen similar to the following appears.

84

If the alarm condition occurs, the specified digital output line is turned on.

To set up limit checking, do the following:

1. Under Limit, click the Enable buttons next to the channels for which you want to define
limits. You can use the Disable All button to quickly stop limit checking on all channels.
For each channel:

2. Enter a value in the Low Limit text box.

3. Enter a value in the High Limit text box.

4. (Optional) Select a Digital Output line to set from the drop-down list box for this channel.

This line is set to 1 when the limit range (high or low) is exceeded.

When multiple channels are configured to set a digital output line, a logical OR condition
exists between them, and any value out of range sets the line to 1.

5. Click Save configuration to apply your changes. If you do not save before leaving this
page, your changes are lost.

You c a n als o clic k the Discard changes button (before you save) to return to the previous
configuration, if desired.

Digital Input and Trigger Configuration

Use the Configuration -> Digital Input & Trigger web page to configure the digital input
lines of your instrument:

Configuring the Instrument Using the Web Interface

To change your digital input configuration, do the following:

1. Describe the digital input lines, if desired, by entering text in the Label field
corresponding to the digital input line that you want to describe.

2. To enable use of an external, digital trigger on digital input line 0, click the Enable
checkbox under the External trigger heading.

3. Click Save configuration to apply your changes. If you do not save before leaving this
page, your changes are lost.

You c a n als o clic k the Discard changes button (before you save) to return to the previous
configuration, if desired.

85

Chapter 5

Digital Output Configuration

Use the Configuration -> Digital Out web page to configure the digital output lines of your
instrument:

To change your digital output configuration, do the following:

1. Describe the digital output lines, if desired, by entering text in the Label field
corresponding to the digital output line that you want to describe.

2. Click Save configuration to apply your changes. If you do not save before leaving this
page, your changes are lost.

You c a n als o clic k the Discard changes button (before you save) to return to the previous
configuration, if desired.

86

Configuring the Instrument Using the Web Interface

Measuring Data and Controlling the Instrument

If your browser supports Java, use the Control web pages start or stop data acquisition on the
sensor channels or to update the value of the digital output line.

Starting and Stopping a Scan

Note: If your browser does not support Java, the Measurement & control -> Acquisition
page of the web interface is not supported. To acquire and view input data, use the
QuickDAQ application instead.

If your browser supports Java, start or stop a scan, using the Measurement & control ->
Acquisition web page.

Press the Start scan button to begin acquiring data from the sensors. The measurements are
displayed on the screen. Press the Stop scan button to stop acquiring data from the sensors.

Notice the following aspects of the display:

• When acquiring data, the Start scan button changes to say Stop scan and the currently

configured scan rate is displayed.

87

Chapter 5

• Each box on the Meter tab represents one of the analog input channels, in the same

position as the physical connectors.

• If you configured custom labels for some of the channels, those labels are shown here

rather than the channel numbers.

• Red boxes indicate that the value is out of range for the specified sensor type.

• The values are updated only for the channels that you enabled, and at the scan rate you

configured.

Controlling the Digital Outputs

Use the Measurement & control -> Digital Output web page to view the current state of the
digital output lines, and manually change them if desired. A screen similar to the following
appears:

88

Green indicates that the digital output line/relay is closed; red indicates that the digital output
line/relay is open.

Note: You cannot change the configuration of digital output lines that were configured for
limit checking on the Configuration -> Limits page.

Configuring the Instrument Using the Web Interface

To change the status of a digital output line/relay, click the Open/Close toggle buttons under
the Change State heading for the digital output lines that you want to change. You can use
these controls to activate or deactivate an external device based on criteria other than
temperature that you define.

89

Chapter 5

Reading the Digital Inputs

Note: If your browser does not support Java, the Measurement & control -> Digital input
page of the web interface is not supported. To acquire and view input data, use the
QuickDAQ application instead.

If your browser supports Java, you can use the Measurement & control -> Digital Input web
page to view the current value of the digital input port while the instrument is scanning. A
screen similar to the following appears:

90

If you configured custom labels for the digital input lines, those labels are shown here.

The Current state LEDs show green if the digital input line is on (relay is closed) or red if the
digital input line is off (relay is open).

Downloading Measurements

Note: This section applies only if your browser supports Java. If your browser does not
support Java, downloading data to a file through the web interface is not supported.

If your browser supports Java, ensure that you have associated CSV files with Microsoft Excel
or Notepad, described on page 74, or the data will be displayed in the browser and not saved
to a file.

If your browser supports Java, you can use the File -> Download Measurements web page to
download your measurement results, including timestamp and limit values, if applicable, to
disk. A screen similar to the following appears:

Configuring the Instrument Using the Web Interface

Measurements taken by the instrument are stored in a large circular buffer; when the buffer is
full, the oldest data is overwritten with the most recent data.

To download your data, do the following:

1. Click the Download button on this page.

If scanning has been stopped, all the data in the buffer is downloaded to a
comma-separated CSV file, starting with the most recent data.

91

Chapter 5

Most Recent Data

Downloaded Data

Beginning of Buffer

Circular Buffer

End of Buffer

Most Recent Data

Oldest Data

Downloading Data

Beginning of Buffer

End of Buffer

Circular Buffer

If scanning is in progress, a snapshot of the data from the most recent data (at the time
that the Download button was clicked) to the oldest data in the buffer is downloaded to a
comma-separated CSV file.

2. In the resulting dialog box, choose Open or Save.

 If you choose Open, the CSV file opens in the associated application (Microsoft Excel

or Notepad).

 If you choose Save, you can open the CSV file in Microsoft Excel, Notepad, or other

utilities for analysis at a later time.

Under some circumstances, your data may be displayed in a frame in the browser, or Excel
may open the data in the frame. Change your Microsoft Excel, Microsoft Explorer, and
Internet Explorer settings to turn off these behaviors and open your files directly in Excel.

92

Part 2: Using Your Instrument

6

Principles of Operation

Block Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

Analog Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

95

Chapter 6

+10 nA Break

Detection

24-Bit

A/D

Isolated

DC-DC

1 of up to 48 Channels

x20

+

–

CJC Per

Point

Isolation Barrier

Control

FPGA

Embedded

Controller

64 kB

SRAM

1 of 8

Digital Input

Isolators

1 of 8

Digital Output

Isolators

37-Pin D-Shell

Connector

ID ROM

ENet

Link
LED

LAN
LED

RJ45

Calibration

ROM

Limit LED

USB LED*

Open TC LED

Ethernet

ENet

Activity

LED

Power LED

*The USB LED is not used
on this instrument.

Block Diagrams

This section includes the block diagrams for the DT8871U, DT8871, and DT8872 TEMPpoint
instruments, DT8873 VOLTpoint instrument, and DT8874 MEASURpoint instruments.

DT8871U Block Diagram

Figure 32 shows the block diagram of the DT8871U TEMPpoint instrument.

96

Figure 32: Block Diagram of the DT8871U TEMPpoint Instrument

DT8871 Block Diagram

Isolation Barrier

Control

FPGA

Embedded

Controller

64 kB

SRAM

1 of 8

Digital Input

Isolators

1 of 8

Digital Output

Isolators

37-Pin D-Shell

Connector

ID ROM

ENet

Link
LED

LAN

LED

RJ45

Calibration

ROM

Limit LED

USB LED*

Open TC LED*

Ethernet

ENet

Activity

LED

Powe r LED

+100 nA Break

Detection

24-Bit

A/D

Isolated

DC-DC

1 of up to 48 Channels

CJC Per

Point

*The USB LED is not used
on this instrument.

Figure 33 shows the block diagram of the DT8871 instrument.

Principles of Operation

Figure 33: Block Diagram of the DT8871 TEMPpoint Instrument

97

Chapter 6

Isolation Barrier

Control

FPGA

Embedded

Controller

64 kB

SRAM

1 of 8

Digital Input

Isolators

1 of 8

Digital Output

Isolators

37-Pin D-Shell

Connector

ID ROM

ENet

Link
LED

LAN

LED

RJ45

Calibration

ROM

*The USB and Open TC LEDs are not
used on this instrument.

Limit LED

USB LED*

Open TC LED*

Ethernet

ENet

Activity

LED

Power L ED

1

2

3

4

+

–

+425 A

Current Source

2.5 Hz Filter

Sense

Return

24-Bit

A/D

Isolated

DC-DC

1 of up to 48 Channels

DT8872 Block Diagram

Figure 34 shows the block diagram of the DT8872 TEMPpoint instrument.

Figure 34: Block Diagram of the DT8872 TEMPpoint Instrument

98

DT8873 Block Diagram

Isolation Barrier

Control

FPGA

Embedded

Controller

64 kB

SRAM

1 of 8

Digital Input

Isolators

1 of 8

Digital Output

Isolators

37-Pin D-Shell

Connector

ID ROM

ENet

Link
LED

LAN

LED

RJ45

Calibration

ROM

*The USB and Open TC LEDs are
not used on this instrument.

Limit LED

USB LED*

Open TC LED*

Ethernet

ENet

Activity

LED

Power L ED

2

1

3

4

+

–

1 M



2.5 Hz Filter

Sense

Return

24-Bit

A/D

Isolated

DC-DC

Gain Select

60

10

1 of up to 48 Channels

Figure 35 shows the block diagram of the DT8873 VOLTpoint instrument.

Principles of Operation

Figure 35: Block Diagram of the DT8873 VOLTpoint Instrument

99

Chapter 6

Isolation Barrier

Control

FPGA

Embedded

Controller

64 kB

SRAM

1 of 8

Digital Input

Isolators

1 of 8

Digital Output

Isolators

37-Pin D-Shell

Connector

ID ROM

ENet

Link
LED

LAN
LED

RJ45

Calibration

ROM

*The USB LED is not
used on this
instrument.

Limit LED

USB LED*

Open TC LED*

Ethernet

ENet

Activity

LED

Power L ED

Channels 32-47

1

2

3

4

+

–

+425 A

Current Source

2.5 Hz Filter

Sense

Return

24-Bit

A/D

Isolated

DC-DC

Channels 16-31

2

1

3

4

+

–

1 M



2.5 Hz Filter

Sense

Return

24-Bit

A/D

Isolated

DC-DC

Gain Select

+10 nA Break

Detection

24-Bit

A/D

Isolated

DC-DC

Channels 0 to 15

x20

+

–

CJC Per

Point

60

10

DT8874 Block Diagram

Figure 36 shows the block diagram of the DT8874 MEASURpoint instrument.

100

Figure 36: Block Diagram of the DT8874 MEASURpoint Instrument