Dionex CD25 Operator's Manual

CD25 CONDUCTIVITY DETECTOR

OPERATOR'S MANUAL

© 2000 Dionex Corporation

Document No. 031687

Revision 01
April 2000

©2000 by Dionex Corporation
All rights reserved worldwide.
Printed in the United States of Amer ica.

This publication is protected by federal copyright law. No part of this publication
may be copied or distributed, transmitted, transcribed, stored in a retrieval system, or
transmitted into any human or computer language, in any form or by any means,
electronic, mechanical, magnetic, manual, or otherwise, or disclosed to third parties
without the express written permission of Dionex Corporation, 1228 Titan Way,
Sunnyvale, California 94088-3603 U.S.A.

DISCLAIMER OF WARRANTY AND LIMITED WARRANTY

THIS PUBLICATION IS PROVIDED “AS IS” WITHOUT WARRANTY OF
ANY KIND. DIONEX CORPORATION DOES NOT WARRANT,
GUARANTEE, OR MAKE ANY EXPRESS OR IMPLIED
REPRESENTATIONS REGARDING THE USE, OR THE RESULTS OF THE
USE, OF THIS PUBLICATION IN TERMS OF CORRECTNESS, ACCURACY ,
RELIABILITY, CURRENTNESS, OR OTHERWISE. FURTHER, DIONEX
CORPORATION RESERVES THE RIGHT TO REVISE THIS PUBLICATION
AND TO MAKE CHANGES FROM TIME TO TIME IN THE CONTENT
HEREINOF WITHOUT OBLIGATION OF DIONEX CORPORATION TO
NOTIFY ANY PERSON OR ORGANIZATION OF SUCH REVISION OR
CHANGES.

TRADEMARKS

Teflon® and Tefzel® are registered trademarks of E.I. duPont de Nemours & Co.
AutoSuppression™, DX-LAN™, IonSep®, MPIC™, OmniPac®, OnGuard™,
SRS®, and Self-Regenerating Suppressor® are trademarks of Dionex Corp.

PRINTING HISTORY

Revision 01, April 2000

Contents

1 • Introduction

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

1.2 About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.2.1 Typefaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.2.2 Safety Messages and Notes . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.3 Safety Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

2 • Description

2.1 Front Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

2.1.1 Control Panel Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

2.1.2 Control Panel Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

2.2 Electronics Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2.3 Conductivity Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

2.4 Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15

2.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16

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2.1.3 Initial Display Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

2.2.1 Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2.2.2 Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2.3.1 DS3 Detection Stabilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

2.3.2 Shielded Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14

2.5.1 Operating and Control Modes . . . . . . . . . . . . . . . . . . . . . . . .2-16

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CD25 Conductivity Detector

2.5.2 Local and Remote Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

2.5.3 Method Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

3 • Operation and Maintenance

3.1 Getting Ready to Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.2 Running Under Direct Control (Local Mode) . . . . . . . . . . . . . . . . . . . 3-2

3.3 Running Under Method Control (Local Mode) . . . . . . . . . . . . . . . . . . 3-3

3.3.1 Running a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3.3.2 Changing the Running Method . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3.3.3 Creating a New Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

3.3.4 Editing an Existing Method . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

3.4 Optimizing Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . 3-7

3.4.1 With a DS3 and Conductivity Cell . . . . . . . . . . . . . . . . . . . . . 3-7

3.4.2 With a Shielded Conductivity Cell . . . . . . . . . . . . . . . . . . . . . 3-8

3.5 Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

4 • Troubleshooting

4.1 No Detector Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2 Low Detector Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4.3 High Detector Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4.4 Noisy or Drifting Baseline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2

4.5 Liquid Leaks from the DS3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

4.6 DS3 Temperature Inaccurate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

4.7 Conductivity Inaccurate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

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4.8 Faulty DX-LAN Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7

4.9 Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8

5•Service

5.1 Eliminating Liquid Leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2

5.2 Removing Trapped Air from the Cell . . . . . . . . . . . . . . . . . . . . . . . . . .5-2

5.3 Replacing the DS3 Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2

5.4 Calibrating the Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4

5.5 Replacing the Main Power Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-6

A • Specifications

Contents

5.6 Physical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

A.1 Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

A.2 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

A.3 Display and Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

A.4 Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

A.5 Conductivity Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

A.6 SRS Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3

A.7 DS3 Detection Stabilizer (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . A-3

B • Installation

B.1 Facility Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

B.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

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CD25 Conductivity Detector

B.2.1 Power Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1

B.2.2 DX-L AN Interfa ce: 10BASE-T Connection s (Optional ). . . . .B-3

B.2.3 DX-LAN Interface: BNC Connections (Optional). . . . . . . . . .B-6

B.2.4 DS3 Detection Stabilizer Installation. . . . . . . . . . . . . . . . . . . .B-9

B.2.5 Shielded Conductivity Cell Installation . . . . . . . . . . . . . . . . . .B-9

B.2.6 DS3 or Shielded Cell Plumbing. . . . . . . . . . . . . . . . . . . . . . . .B-9

B.2.7 Recorder/Diagnostic Connection . . . . . . . . . . . . . . . . . . . . . .B-17

B.3 Automatic SRS Power Control (Optional) . . . . . . . . . . . . . . . . . . . . .B-18

C • User Interface

C.1 Operational Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-2

C.1.1 Menu of Screens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-2

iv

C.1.2 Main Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-3

C.1.3 Detail Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-4

C.1.4 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-5

C.1.5 Module Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-7

C.1.6 Analog Out Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-8

C.1.7 Time Function In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-9

C.2 Diagnostic Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-10

C.2.1 Diagnostic Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-10

C.2.2 Power-Up Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-11

C.2.3 Elapsed Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-12

C.2.4 Analog Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-13

C.2.5 DX-LAN Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-14

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C.2.6 Keyboard Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-16

C.2.7 Diagnostic Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-17

C.2.8 Leak Sensor Calibration and Status. . . . . . . . . . . . . . . . . . . . C-19

C.2.9 Signal Statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-20

C.2.10 Calibrate Conductivity Cell. . . . . . . . . . . . . . . . . . . . . . . . . . C-21

D • TTL and Relay Control

D.1 TTL and Relay Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2

D.2 TTL and Relay Output Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3

D.3 TTL Input Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4

D.3.1 TTL Input Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4

D.3.2 TTL Input Signal Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-5

Contents

E • Signal Processor Functions

F • Connector Pinouts

F.1 Recorder/Diagnostic Signal Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . F-1

F.1.1 Signal Electrical Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . F-2

F.2 TTL/Relay Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-4

F.3 DS3 Connector Pinouts—SCR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-5

F.4 SRS Connector Pinouts—SCR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-6

F.5 Conductivity Cell Connector Pinouts—SP . . . . . . . . . . . . . . . . . . . . . F-6

G • Reordering Information

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v

CD25 Conductivity Detector

vi

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1.1 Overview

The CD25 Conductivity Det ect or is a sensitive, accurate , and versatile ins tr ument
for detecting and quant ifying ionic analytes in liq uid and ion chromatog raphy. It is
especially useful for analytes that lack UV chromophores and cannot be
determined with adequate sensitivity by UV absorbance. Conductivity detection,
especially when combined with chemical eluent suppression, provides excellent
sensitivity and selectivity for numerous ionic species, both organic and inorganic.

The major organic analytes are carboxylic, sulfonic, and phosphonic acids; and
primary, secondary, tertiary, and quaternary amines. Inorganic analytes include
strong acid anions such as the halid es, sulfate , nitrat e, and phos phate; alkali metal
and alkaline earth cations.

The CD25 ca n be controll ed locally, from the front panel, or remotely (via th e
Dionex DX-LAN™ interface) from a host computer running PeakNet 6, Release

6.1 (or later) software.

1 • Introduction

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1-1

CD25 Conductivity Detector

1.2 About This Manual

Chapter 1

Introduction

Chapter 2

Description

Chapter 3

Operation and

Maintenance

Chapter 4

Troubleshooting

Chapter 5

Service

Appendix A

Specifications

Appendix B

Installation

Appendix C

Display Screens

Provides a brief overview of the CD25 Conductivity
Detector. Explains the meaning of safety messages and
icons in the manual and safety labels on the detector.

Describes physical aspects of the CD25, including the
front panel controls, electronics, and flow cell. Explains
the detecto r operating m odes.

Describes operating features and how to create, edit, and
run methods from the CD25 front panel. Lists routine
preventive maintenance requirements.

Lists possible causes of problems and step-by-step
procedures to isolate and elimina te th em.

Contains step-by-step instructions for routine service and
parts replacement procedures.

Lists the CD 25 specifica tions and installation site
requirements.

Describes how to install the CD25.

Illustrates and describes all operating and diagnostic
screens that can be displayed on the front panel.

1-2

Appendix D

TTL and Relay

Control

Appendix E

Signal Processor

Functions

Appendix F

Connector

Pinouts

Appendix G

Reordering

Information

Describes TTL and relay control functions. Provides
connection instructions.

Lists the functions of the Signal Processor (SP) card.

Describes the pinouts for all CD25 connectors.

Lists spare parts for the detector.

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1.2.1 Typefaces



Capitalized bold type indicates a front panel button:

Enter

Press



Uppercase bold type indicates the name of a menu or a screen, or an
on-screen entry:

1 • Introduction

to begin running the method.

Go to the

METHOD

Move the cursor to the

screen.

EDIT

field.

1.2.2 Safety Messages and Notes

This manual contains warnings and precautionary statements that can

prevent personal injury and/or damage to the CD25 when properly

followed. Safety messages appear in bold type and are accompanied by

icons, as shown below.

Indicates an imminently hazardous situation which, if not

avoided, will result in death or serious injury.

Indicates a potentially hazardous situation which, if not

avoided, could result in death or serious injury.

Indicates a potentially hazardous situation which, if not

avoided, may result in minor or moderate injury.

Indicates that the function or process of the instrument may be

impaired. Operation does not constitute a hazard.

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1-3

CD25 Conductivity Detector

Informational messages also appear throughout this manual. These are labeled
NOTE and are in bold type:

NOTE NOTES call attention to certain information. They alert

you to an unexpected result of an action, suggest how to

optimize instrument performance, etc.

1.3 Safety Labels

The CE and GS safety label on the CD25 attests to compliance with the following
European, EMC, and safety requirements: Council Directives 73/23/EEC and 89/
336/EEC, EN 61010-1:1993 (safety), EN 50082-1:1992 (susceptibility), and EN
55011:1991 (emissions).

The symbols below appear on the CD25 or on CD25 labels.

Alternating current

˜

Protective conductor terminal (earth ground)

Power supply is on

Power supply is off

1-4

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2.1 Front Control Panel

The control panel on the f ront door of t he CD25 contains the liquid crystal di splay
(LCD), the membrane keypad, and the actuator for the main power switch. The
electronics chassis, described in Section 2.1.3, is located behind the front door.

Power Switches

The main power switch is on a bulkhead inside the electronics chassis (in the
front, left-hand corner). The actuator for the power switch is on the front door,
below the control panel (see Figure 2.1.2). The actuator functions only when the
front door is fully closed. When the door is open, press the main power switch to
turn the CD25 on and off.

2.1.1 Control Panel Display

2 • Description

and

screen

, displays CD25 status and operating

Menu

buttons (see Figure 2-1).

option on the

MODULE SETUP

screen

The LCD, also called the

information. Fields on the sc ree n tha t ar e in reverse video (blue lette rs on

a white background) can be edited, while normal video fields are simply

informational displays.



To adjust the screen contrast, rotate the knurled knob in the recess
below the



To adjust the brightness of the screen backlight, select a different

DISPLAY PANEL BACKLIGHT

(see Section C.1.5).

Help

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2-1

CD25 Conductivity Detector

MAIN SCREEN
DETAIL SCREEN
METHOD

---









E

!

"



 



Main Power
Switch Actuator





Ta b
(for opening
the door)

Figure 2-1. CD25 Front Panel

2.1.2 Control Panel Keypad

The buttons on the front panel keypad are used to affect screen functions,
to directly control CD25 operat ion, and to create and modif y programmed
series of timed events, called methods. For example, pressing
turns the method clock off
displays a list of availa ble screens. In summary:



To go from a menu to a screen, press the number button that
corresponds to the screen’s number on the menu, or move the cursor
to the desired screen name and press

Hold

(



Knob
(for a d ju s tin g
the contrast)

) and on





Run

, while pressing

(

)

Enter

.









#



Hold/Run

Menu

2-2



To edit a reverse video entry field on a screen, move the cursor to the
field using the four directional arrow buttons. Then, use the numeric

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2•Description

Keypad
Buttons

Offset

Mark

buttons to enter variable values or the

Select

∆

and

Select

∇

to choose predetermined values.



In most cases, confirm the selected value, by pressing either a cursor
arrow button or
must press

METHOD SAVE TO

the
command, the

NOTE A beep sounds each time you press a keypad button,

and a lower frequency beep sounds whenever an
error occurs. You can disable the beeps from the

MODULE SETUP

Function

Returns the analog (recorder) output to a predetermined baseline and
zeros the display. The resultant value of the offset required is displayed
on the

Sends a 10% positive event mark to the analog (recorder) output. A
mark is typically used to indicate a sample injection. This fun ction can
be programmed in a method.

Enter

. In certain fields and/or screens, however, you

Enter

to confirm the selected value. These exception s are

field, the

DIAGNOSTIC TESTS

DETAIL

screen. This function can be programmed in a method.

METHOD RUN

field, any calibration

screen, and all menu screens.

screen (see Section C.1.5).

buttons

Insert

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Inserts a new step into a method.
T o add a new s tep, mov e the cur sor to the

A new blank step appears below the cursor position. After entering a
time value, press
order and they will be automatically reorganized in the correct
chronological order.

Enter

or a cursor arrow button. Insert steps in any

TIME

field and pr

ess

Insert

.

2-3

CD25 Conductivity Detector

Keypad
Buttons

Delete

Hold/Run

Function

Removes the value from the curren t entry field. To restore the previous
value, move the cursor from the field before entering a new value.

Pressing

METHOD

Delete

when the cursor is in a step entry field on the

screen “blanks” the step parameter value. Moving the cu rsor
to another field does not restore the previous value; instead, the step
remains blank, indicating no change from the previous step .

To delete an entire method step:

1. Position the cursor in the method’s time field and press

Delete

.

The time is removed and the help line prompts you to press

Delete

again to delete the step.

2. Press

Turns the method clock off (

Delete

again. Or, to restore the original time and step

parameters, press any button except

Hold

) and on

Delete

(Run)

.

. This button
functions only when the detector is under Method control (see
Section 2.5.3).

When the method clock is in Hold, pressi ng

Hold/Run

starts the clock
at either the initial step of a new method or, if resuming an interrupted
method, at the time at which the clock was put in Hold.

2-4

Rese

Select

and

Select

When the method clock is in Run, pressing

Hold/Run

stops the
method clock, thereby “holding” the method and freezing the current
conditions.

t

Changes the method clock time to

INIT

, causing the initial conditions
specified by the method to occur. This button functions only when the
detector is under Method control (see Section 2.5.3).

If the method is running, it continues running. If the method is in Hold,
the method clock executes the initial conditions and holds.

∆

When the cursor is positioned at a field with predetermined
parameters, these buttons cycle through the options. In fields with

∇

predetermined numerical values, pressing

Select

Enter

Select

button increases (or decreases) the value

by one unit; pressing
Holding down a
continuously. Press

∇ decreases the value by one unit.

or a cursor arrow button to confirm the

Select

increases the value

∆

selected value.

Doc. 031687-01 04/2000

2•Description

Keypad
Buttons

Help

Menu

Numeric
Buttons

Function

The four cursor buttons move the cursor, in the direction of the arrow,
to the next entry field. If there is no changeable field in that direction,
the cursor moves diagonally or remains in its current location.

In most cases, after entering a new value in an entry field, pressing an
arrow button saves and/or executes the change. The exceptions are the

METHOD SAVE T O

command, the

DIAGNOSTIC TESTS

field, the

METHOD RUN

screen, and all menu screens.

field,

any calibration

Displays a help screen with information pertaining to the current entry
field.

Displays one of two menus, depending on the current screen:



From an operational screen, pressing

SCREENS



From a diagnostic screen, pressing

DIAGNOSTIC MENU
MENU of SCREENS

.

; pressing

.

Menu

displays the

Menu

once returns you to the

Menu

again returns you to the

MENU of

Enters numeric values into the current e ntry field. The numer ic buttons
are 0 through 9 and the decimal.

From a menu screen, pressing a numeric button opens the
corresponding screen.

Enter

Doc. 031687-01 04/2000

Saves and/or executes changes made in entry fields. I f a menu screen is
displayed, pressing

Enter

opens the highlighed screen.

2-5

CD25 Conductivity Detector

2.1.3 Initial Display Screens

When the CD25 has successfully powered-up and passed all diagnostic
tests, the
the
power-up, the
screen. See Section C.2.7 if this occurs.

POWER-UP

MAIN

screen (see Figure 2-3). If one of the diagnostic tests fails at

DIAGNOSTIC TEST

screen (see Figure 2-2) displays briefly, followed by

screen disp lays instead of the

MAIN

NOTE The information on the

reviewed at any time by selecting the screen from

DIAGNOSTIC MENU

the

CD25 CONDUCTIVITY DETECTOR

MODULEWARE REV

Help M essag e

Figure 2-2. Power-Up Screen

+2. 34

uS

POWER-UP

.

TOTA L 138.71 uS

RANGE

screen can be

BIO S REV n.nn

SRS

n.nn
nnnnnnDX L-AN ID#

50

1000 uS

2-6

LOCAL

H e lp Mess a g e

MAIN

The
facilitate viewing from a d istance. Operating parameters (flow rate,
method number to run, etc.) are selected here.

screen dis plays status information in enlarged characters to

METHOD 05

Figure 2-3. Main Screen

Doc. 031687-01 04/2000

2•Description

To access other screens, press the
display the

MENU of SCREENS

Menu

(see Figure 2-4). T o select an opti on, move
the cursor to a screen name and press
on the keypad and press

Enter

. See Appendix C for a description of each
screen.

MENU of SCREENS

MAIN SCREEN

1

DETAIL SCREEN

2

METHOD

3

- - -

4

5
6
7
8

Help Message

Figure 2-4. Menu of Screens

button on the front panel to

Enter

, or enter the screen number

MODULE SETUP
ANALOG OUT SETUP
TIME FUNCTION IN
DIAGNO STIC MENU

Doc. 031687-01 04/2000

2-7

CD25 Conductivity Detector

2.2 Electronics Chassis

The electronics chassis is located immediately behind the front door of the CD25 .
The chassis contai ns several el ectronics ca rds (printe d circuit boa rds) that ar e used
to control the CD25. Various connectors on the cards allow communication
between the CD25 and other system modules and accessories. Figure 2-5
identifies the cards and their connectors.

Do not remove any of the electronics card s from the detector.
There are no user-serviceable components on the cards. If
servicing is required, it must be performed by qualified
personnel using appropriate electrostatic discharge (ESD)
handling procedures.

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Figure 2-5. CD25 Electronics Chassis Components

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2-8

Doc. 031687-01 04/2000

2.2.1 Connectors

Recorder (Slot 2)

This connector is typi cally used for a recorder/integrator or diagnostic
instruments. For a description of the connector pinouts, see Table F-1 in
Appendix F. For connection instructions, see Section B.2.7.

DS3 (Slot 2)

The control cable from the DS3 Detection Stabilizer connects here.

SRS® (Slot 2)

The control cable from the Self-Regener at ing Suppressor® conne ct s her e.

Conductivity Cell (Slot 3)

The conductivity cell cable connects here.

TTL/Relay (Slot 4)

This strip of eight connectors provides an interface with Dionex and non­Dionex modules for TTL and relay control of the detector. See
Appendix D for a description of relay and TTL functions and the
connections between the CD25 and other modules.

2 • Description

60-pin Ribbon Connector (Slot 5)

The 60-pin ribbon cable to the CD25 front panel (display and keypad)
connects here.

2.2.2 Cards

Power Supply Card

Provides 45 watts of power for the detector electronics.

Blank Card

Slot 1 contains a blank card that must be present to complete the
electromag netic interference (EMI) shielding.

Doc. 031687-01 04/2000

2-9

CD25 Conductivity Detector

SCR (Supply Control/Relay) Card

Interfaces to the CPU; th e card contains three functions:

16-bit Recorder Output Digital-to-Analog Converter



electronic switch for selection of full-scale outputs of 0.01, 0.1, and

1.0 V.

SRS Power Supply



50, 100, 300, or 500 mA to the suppressor. An over-voltage detector
shuts off the power i f the vol tage ex cee ds 8.5 V. An over- temp eratur e
detector shuts off the power if the SRS temperature excee ds 40
either of these events o ccurs, the S CR card sends an “SRS Alarm”
error message to the CPU.

DS3 Power Supply



Stabilizer . While warmi ng or coolin g to a lowe r set poin t, a “BELOW
TEMP” or “ABOVE TEMP” message is displayed. Once a set point
in the range of 25 to 45
maintains a constant temperature .

SP (Signal Processor) Card

—Includes an

—Supplies a regulated current (set by the user) of

°

C. If

—Supplies heating power to the DS3 Detection

°

C is reached, proportional heat control

2-10

Contains all the analog circuitry needed by the CD25, as well as the
digital circuitry required to interface to the CPU. See Appendix E for a
list of SP ca rd functions.

Relay/DX-LAN and CPU Cards



The CD25 control Moduleware and BIOS reside on the CPU card.
The CPU card provides control and monitoring of other modules. A
60-pin ribbon cable assembly links the logic to the CD25 front panel
display a nd keypad .



The Relay I/O card provides two isolated low voltage relay outputs,
two TTL outputs, and four TTL inputs.

The cards are installed in slot 5 of the card cage. The Relay card is a half­card which rides piggyback on the CPU card and sits behind slot 4.

The Relay I/O card is short enough to allow th e optional detector interface
card (P/N 044196) to be mount ed behi nd it in slot 4. The interface card is
required for communica tion bet ween the CD25 an d PeakNet so ft ware via
the DX-LAN.

Doc. 031687-01 04/2000

2 • Description

Power Supply LED

The multicolored LED below the TTL/Relay connections indicates the
power supply status:



A green LED indicates normal operation.



A red LED indicates a fault conditi on. When a fault occurs, th e CD25
enters its diagnostic state and no other control is permitted until the
problem is corrected. Turning off the power for a few seconds may
clear the fault; however, if the red LED is lighted when you turn on
the power again, notify Dionex.

Doc. 031687-01 04/2000

2-11

CD25 Conductivity Detector

2.3 Conductivity Cell

The flow-through conductivity cell has an active volume of about 1.0 µL. T wo
316 stainless stee l elect rodes are permanentl y sealed into the PEEK cell bo dy. The
cell constant has a nominal value of 160 cm
sensor located slightly downstream from the electrodes senses the temperature of
liquid passing thro ugh the cell. The me asured value is used to provid e temperature
compensation.

The advanced geometry of the cell provides several benefits:



Excellent accuracy and linearity over the working range



Efficient sweepout and low volume for low dispersion



Reduced sensitivity to electrode surface conditions



Low electrode mass



Effective temperature compensation

You can order the conductivity cell installed in a DS3 Detection Stabilizer
(P/N 044130) for temperature control, or installed in an electrical shield
(P/N 044132) which provides no temperature control. Bec ause th e DS3 maintai ns
a constant temperature, thus reducing the effects of variations in laboratory
temperature, the DS3 is recommended for conductivity detection.

-1

and is calibrated electronically. A

2-12

Temperature Control and Compensation

Temperature directly affects the conductivity of a solution. As conductivity
increases, the effect of temperature changes becomes more pronounced. For
example, building temperature control systems can cause a regular oscillation in
the baseline. This, in turn, can affect the reproducibility of an analysis.

In ion chromatography, suppressing eluent conductivity minimizes the effect of
temperature variation. Temperature compensation further improves baseline
stability. When the conductivity cell is housed in a DS3 Detection Stabilizer, the
DS3 enhances the ability of these techniques to reduce temperature effects below
the detection limit.

Temperature compensation also ensures that th ere will be no major chang e in the
baseline or peak heights, should it be necessary to change the DS3 operating set

°

point. Readings will be normalized to 25

C.

Doc. 031687-01 04/2000

2.3.1 DS3 Detection Stabilizer

The DS3 is a temperature-controll ed chamber c onsisting of a cast
aluminum base and cover enclosed in insulating foam. The chamber
houses both the conductivity cell and the eluent heat exchanger.
Figure 2-6 identifies the major components of the DS3.

The DS3 provides the following benefits:



Conductivity measurements that are nearly impervious to laboratory
temperature variation



Very low dispersion in the eluent heat exchanger



Excellent peak height reproducibility



Remote mo unting after either the column or suppressor



User-settable temperature

Power input to a pair of trans istors on op posite sid es of the DS3 heat s it to

°

a set temperature from 25
outlet senses the eluent temperature. The CD25 circuitry compares this
temperature with the user-selected temperature and adjusts the heat input
in real time to hold the temperature within a few millidegrees.

C to 45 °C. A sensor near the heat exchanger

2 • Description

The DS3 is sealed with an O-ring to trap eluent that may leak from the
cell. If 5 mL of liquid acc umulates, a thermistor s ensor becomes
immersed and signals a leak to the CPU. Any additional leakage will be
discharged via the spill/overflow line. A second thermistor, above the
discharge level, acts as a temperature re ference for the leak sensor.

Doc. 031687-01 04/2000

2-13

CD25 Conductivity Detector

To Detector
Electronic s

Conductivity Cell

Ground Wire

Ce ll Inlet

Figure 2-6. DS3 Detection Stabilizer

2.3.2 Shielded Cell

A conductivity cell installed in an electrical shield (P/N 044132) is
available. The shield is a stainless steel housing that protects the cell from
electromagnetic interference (EMI), but does not provide temperature
control.

DS3
Inle t

DS3
Outlet

Sp ill/Overflo w
Line

DS3
Enclosure

Keyhole Mounting
Slots

2-14

Doc. 031687-01 04/2000

2.4 Rear Panel

The CD25 rear panel (see Figure B-1) contains fuses, connectors for line power,
and a connection for the optional DX-LAN interface.

DX-LAN Connection (Optional)

When you order the DX-LAN network, a DX-LAN connector is factory-installed
in the upper left corner of the CD25 r ear panel (see Figure B-1). See Appendix B
for DX-LAN interface connection instructions.

External Connection Access

Connections to the front of the electronics chassis, such as TTL and relay cables,
are usually rout ed to t he back of the d etector through t he cab le chase in the bo ttom
of the electroni cs chass is. The y may also be pass ed throug h slots at the front o f the
detector. Cables exit the CD25 through an opening in the rear panel (see
Figure B-1).

2 • Description

Doc. 031687-01 04/2000

2-15

CD25 Conductivity Detector

2.5 Functional Description

2.5.1 Operating and Control Modes

The operating mode determines

how

the CD25 receives operating

commands:



In Local mode, the CD25 receives commands from the front control
panel buttons and screens.



In Locked Remote mode, PeakNet 6 software sends commands from
the host computer via the DX-LAN interface.

The control mode determines



In Direct control, the CD25 executes commands immediately.



In Method control, the CD25 executes commands according to the

when

operating commands are executed.

timed steps in a method. The method is programmed from the CD25
front panel.

The table below summarizes the various operating and control mode

MAIN

configurations. Select the modes from the
Section C.1.2),

DETAIL

screen (see Section C.1.3), or chromatography

screen (see

software.

Operating/Control Mode Detector Operation

Local/Direct Control Commands are entered from the CD25 front control

panel and executed immediately after being entered.

2-16

Local/Method Commands are entered from the CD25 front control

panel and executed by running a method programmed
from the front panel.

Locked Remote/Direct
Control

Commands are sent from PeakNet 6 and executed
immediately when received.

Doc. 031687-01 04/2000

2.5.2 Local and Remote Modes

Local Mode

When the CD25 is powered up, it is a lways in Loc al mode. In Loc al mode
the detector accepts operating commands from two sources:



Direct input from the front panel keypad and screens. All operating
functions are available with direct input.



TTL inputs from a remote controller (for example, a Dionex gradient
pump module or an integrator). TTL signals can be used to offset the
recorder, run a method, turn the SRS off and on, send a mark to the
recorder, and increase the recorder range.

Locked Remote Mode

In Locked Remote mode, the CD25 accepts operating commands from a
Dionex data station via the DX-LAN.

In Locked Remote mode, all operating changes from the front panel are
disabled. Selecting the Connect command from PeakNet 6 immediately
selects the Locked Remote mode. To return the CD25 to Local mode,
select the Disconnect command, or turn off the CD25 power.

2 • Description

2.5.3 Method Control

In Method control, commands are executed according to the time-based
steps specified in a metho d. Methods are crea ted, edite d, and saved on the

METHOD

instructions.

METHOD EDIT SAVE TO

TEMP COMP

TIME

INIT

0.00

2.00

Help M essag e

Doc. 031687-01 04/2000

screen (see Figure 2-7). See Section 3.3 for programming

RUN

RANGE

200 uS

v

1.6
OFFSET MARK

**

Figure 2-7. Method Screen

3333

SRS 100DS3 TEMP 40

TTL RLY

1
0

1

25

212
000

1

2-17

CD25 Conductivity Detector

The following summarizes basic information about using methods:



The CD25 can run under method control while you are entering or
editing any method (including the one that is currently running).



When saving changes to the currently running method, or switching
to a different method, the method cloc k continue s running unaf fected.
Only those p arameter changes which affect the method after the
current time will be implemented in the current run.



The CD25 can store up to 100 separate methods (0 through 99) in
memory. The actual number, which depends on the size of each
method and the amount of available memory, is typically less than
this.



Methods are retained in memory even after the CD25 is powered
down.



Each method can have a maximum of 32 time-based steps. Step 1
always starts at

0.0.

INIT

(initial conditions). Step 2 always starts at

TIME

=

2-18

Doc. 031687-01 04/2000

3 • Operation and Maintenance

3.1 Getting Ready to Run

NOTE The CD25 is designed for use with IC (ion

chromatography) and HPLC (high-performance liquid
chromatography) applications and should not be used
for any other purpose. If there is a question regarding
appropriate usage, contact Dionex before proceeding.

After installing the CD25 Conductivity Detector, or after the power has been off
for some time, use the following check list to ready the detector for operation.



Verify that all cables are correctly connected to the CD25.



Verify that the CD25 power cord is plugged into the main power.



Press the power switch actuator on the CD25 front panel (see Figure 2-1) to
turn on the power. The
diagnostic tests begin running. If the tests are successfully completed, the

MAIN

screen appears after a few seconds. If one or more tests fails, the

DIAGNOSTIC TEST

POWER-UP

screen appears, inst ead.

screen displays briefly and then some



If the conductivity cell is in a DS3 Detec t ion Stabiliz er, set the DS3
temperature from the
guidelines:

If the DS3 is installed in a non-temperature controlled module, for
example, an LC10 Chromatography Organizer or LC20 Chromatography
Enclosure, select a temperature at least 5 °C above the highest expected
ambient temperature surrounding the DS3.

If the DS3 is installed in an LC30 Chromatography Oven, select a
temperature at least 5 °C above th e oven te mperatu re. Do not set t he oven
temperature above 40 °C (104 °F).



Turn on the DS3 power. The DS3 will begin warming up at about
1 °C/minute. Baseline conducti vit y should stabilize once the DS3 reaches the
selected temperature.

Doc. 031687-01 04/2000

DETAIL

screen (see Section C.1.3), according to these

3-1

CD25 Conductivity Detector



As soon as the proper current is determined and eluent is flowing through the
Self-Regenerating Suppressor (SRS) at the correct rate, turn on the SRS. (The
SRS power is always off when the CD25 is powered up.) After start-up, the
usual direction of drift is downward as SRS efficiency improves.



While waiting for acceptable drift, you may want to select a lower sensitivity.
Set the offset to 50%.



When you are ready to start a run, select the desired sensitivity and offset (if
you have not already do ne so). Pr ess

Offset

before injection and du ri ng a run,

also, if nec essary.

3.2 Running Under Direct Control (Local Mode)

In the Direct cont rol operat ing mod e, commands a re ca rrie d out immediat ely a fter
they are entered. All detector pa ramete rs remai n in ef fect unti l new comma nds are
entered. Because ther e ar e no ti me- base d st eps, the method clock is not used. The

Hold/Run

and

Reset

buttons are not operable in Direct control.

Select Direct control from the

DIRECT CNTRL



If

is displayed, this mode is already selected and no action is

necessary.

METHOD



If

Select

or

is displayed, move the cursor to

∇

button to toggle to

button to activate the selection.

MAIN

or

DIRECT CNTRL

DETAIL

screen, as follows:

METHOD

. Press

and press the

Enter

or a cursor arrow

Select

∆

3-2

Doc. 031687-01 04/2000

3 • Operation and Maintenance

3.3 Running Under Method Contr ol (Local Mode)

In the Method control operating mode, the CD25 is controlled by a series of
programmed timed events, known as a
even after the detector power is turned off.

3.3.1 Running a Method

method

. Methods are retained in memory

1. Go to the

CNTRL

to

2. In the

METHOD

Enter

or a cursor arrow button.

NOTE The method can also be selected from the

MAIN

METHOD

DETAIL

or

screen. If necessary, toggle from

.

field, enter the desired method number and press

METHOD

the

screen. Enter the method number in

RUN

field and press Enter.

DIRECT

3. If the method clock is already running, the method will start as soon
as you enter the method number. If the clock is in Hold, press

Hold/Run

to start the method.

4. The elapsed time on the method clock when the method begins
determines at which step the method begi ns runni ng:



If the method clock is at
running using the

INIT

INIT

or time zero, the method begins

condition parameters, f ollowed by the t ime
zero step. The remaining steps are executed according to their
programmed times.



If the method clock is greater than zero, the method begins
running using the paramete rs speci fi ed in the step for the elapsed
time. To start the method at the

Reset

.

INIT

conditions instead, press

3.3.2 Changing the Running Method

To switch from the method currently running to a different method, enter
the new method number in the

Enter

. The new method will begin running, using the parameters
specified in the step for the current elapsed time. If you prefer to start the
method at the

Doc. 031687-01 04/2000

INIT

conditions, press

RUN

field on the

Reset.

METHOD

screen and press

3-3

CD25 Conductivity Detector

3.3.3 Creating a New Method

1. Go to the

METHOD

screen. In the

number from 0 through 99 and press

EDIT

field, enter an

Enter

unused

method

or a cursor arrow button.

This displays a blank method on the screen.
The first step of every meth od is an in itia l condi tions step wi th

TIME

the

TIME

field. The second step is always a time step with 0.00 in the

field. You cannot delete these steps, although you can change

their parameters.

2. Enter the parameters for the initial conditions and time 0.00 steps.

NOTE The

METHOD EDIT SAVE TO

TEMP COMP

TIME

field is the only field in each method step
that must have an entered value. Leaving any other
field blank indicates that the value selected for that
parameter in the preceding step is still in effect.

RUN

3333

1.6

25

SRS 100DS 3 TE M P 40

TTL RLY

TIME

INIT

0.00

2.00

RANGE

200 uS

v

OFFSE T M ARK

**

1

212

0

000

1

1

Help M essage

INIT

in

3-4

Figure 3-1. Method Screen

3. To create a new method step, move the cursor to a blank

TIME

field,

enter the time (in minutes) for the action to be performed, and press

Enter

or a cursor arrow button. Enter a value for each step parameter,
or leave a field blank if you want the value selected in the preceding
step to remain in effect.

4. Repeat Step 3 for each additional step. Up to 30 steps can be added
after the time 0.00 step.

Sometimes a method contains more steps than can be seen on the

v

screen at one time. If there is a small
bottom of the screen, move the cursor

next to the time entry at the

down

to view additional steps.
If there is a caret (^) next to the top tim e entry, move the cursor up to
view additional steps.

Doc. 031687-01 04/2000

3 • Operation and Maintenance

5. To save the new method, move the cursor to the
the number that appears in the

3.3.4 Editi n g an Ex is ting Method

NOTE Once you sav e chan ges to a m eth od, t here i s no way

to recall the original method. To make experimental
changes while retainin g th e orig inal me thod , be s u r e
to save the new method, or a copy of the original
method, under a different method number.

Y ou can modify an existi ng method by changing, ad ding, or deletin g steps
and/or parameters. If the method you are editing is currently running, the
changes are stored in memory and implemented when you save the
method.

To edit an existing method, go to the
number in the

Follow the editing instructions in the appropriate section below. When
you finish, save t he cha nges t o the curr ent me thod nu mber or s elect a ne w
number.

Changing Method Parameters

EDIT

field, and press

EDIT

field, and press

METHOD

Enter

screen, enter the method

or a cursor arrow button.

SAVE TO

Enter

field, enter

.

Move the cursor to the desired field and enter a new value, using the
CD25 front panel buttons. Press
editing change.

Adding a Method Step

There are two ways to add a step to an existing method:





Doc. 031687-01 04/2000

Enter

or a cursor arrow button after each

Move the cursor on the

METHOD

screen to any

time and pa rameters for the new step, and press

TIME

field. Enter the

Enter

or a cursor
arrow button. If neces sary , the step will automatical ly be moved to th e
correct chronological point in the method.

Move the cursor on the
preceding the intended location of the new step. Press

METHOD

screen to the line immediately

Insert

to insert
a blank line below the cursor location . Enter the time and parameters
for the new step, and the n press

Enter

or a cursor arrow button.

3-5

CD25 Conductivity Detector

Deleting a Method Step

Delete

METHOD

twice.

METHOD

screen to t he time of the step to be

screen to the

EDIT

Move the cursor on the
deleted and press

Deleting an Entire Method

Move the cursor o n the
twice.

Saving a Modified Method

replace

To
of the original method in the

retain

To

the original me th od wi t h a m odi fi ed version, ente r the number

SAVE TO

field and press

the original method an d sa ve t he modi fi ed version elsewhere in

memory, enter an unused method number in the

Enter

.

field and press

Enter

.

SAVE TO

field and press

Delete

3-6

Doc. 031687-01 04/2000

3 • Operation and Maintenance

3.4 Optimizing Temperature Compensation

The CD25 built-in temperature compensation stabilizes conductivity readings by
correcting for changes in ambient temperature that occur during a run. For more
information about temperature control and compensation, see Section 2.3.

3.4.1 With a DS3 and Conductivity Cell

If the ambient temperature exceeds 45 °C, the DS3 may be
permanently damaged. If the DS3 is installed in an LC30
Chromatography Oven, do not se t the ov en temp erat ure abo v e
40 °C (104 °F).

Housing the cell in a DS3 Detection S tabilizer ensures that there is no
more than a minor temperature varia tion in liquid re aching th e cell. Thus ,

TEMP COMP

the

setting on the

Many users are able to keep their systems at a single operating
temperature. For optimal accuracy, calibrate the cell at this temperature,
using the proper temperature coefficient setting. If you later reset the
temperature, the CD25 temperature compensation will normalize
conductivity measurements to 25 °C (77 °F) to prevent a major upset in
system calibration. If you change the DS3 set point, recalibrate the cell.

DETAIL

screen can remain at 1.7% per ºC.

If temperature-induced baseline cycling occurs, it is probably caused by
another component of the chromatography system. If the variation
increases as the eluent reservoir empties, move the reservoir to a more
temperature-stable environment and/or wrap the reservoir in thermal
insulation.

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3-7

CD25 Conductivity Detector

3.4.2 With a Shielded Conductivity Cell

When the conductivity cell is not inside a DS3 Detection Stabilizer, actual
conductivity drifts up and down with fluctuations in laboratory
temperature. This is especially noticeable when the thermostat cycles on
and off in laboratories with very high air turnover rates and controlled
temperature. Selecting the proper temperature compensation factor will
minimize the effect of temperature fluctuations.

Start by setting

TEMP COMP

baseline variation of the same period as the laboratory cooling or heating
occurs, increase or decrease the temperature compensation setting.
Continue adjusting it until you find the optimal setting. This is typically
between 1.5% to 2% per ºC, suppressed or non-suppressed.

If you notice a slowly increasing or decreasing baseline drift in a
laboratory with out a te mperature control system, l ook for a cor responding
temperature drift. If there is a correlation, adjust the temperature
compensation setting until you find the optimal setting.

3.5 Routine Maintenance

This section describes routine maintenance procedures that can be performed by
the user. Any other maintenance procedures must be performed by qualified
Dionex personnel.

NOTE The CD25 electronic components are not customer-

serviceable. Repair of electronic components must be
performed by Dionex.



Periodically check liquid line conne ctions to the cell (inside the
chromatography module) for leaks, and clean up any spills.

on the

DETAIL

screen to 1.7%. If a sinusoidal

3-8

Doc. 031687-01 04/2000

This chapter is a guide to troubleshooting problems that may occur while
operating the CD25 Conduc ti vi ty De te ctor. Turn to the section that b est des cr ibe s
the operating problem. There, the possible causes of the problem are listed in
order of probability, along with the recommended courses of action. For
additional help, refer to Appendix C for instructions on running the CD25
diagnostics program.

If you are unable to eliminate a problem, contact Dionex. In the U.S., call 1-800­346-6390 and select the Technical Support option. Outside the U.S., call the
nearest Dionex office.

4.1 No Detector Response

Cell is off



4 • Troubleshooting

Turn on the cell (from the

Analog output range set too high; although the display indicates a



response, no recorder response observed

Select a more sensitive analog output range.

Wrong full-scale output (or no full-scal e output) selected



Select 0.01, 0.10, or 1 volt full-scale.

No flow from pump



Check the pressure reading on the pump to verify that the pump is on.

Detector o f fset out of range



Offset

Press

on the CD25 front panel.

MAIN

or

DETAIL

screen).

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4-1

CD25 Conductivity Detector

4.2 Low Detector Output

Analog output range set too high; although the display indicates a



response, no recorder response observed

Select a more sensitive analog output range.

Insufficient sample injected



Increase the injection size or concentration.

Cell out of ca libration



Recalibrate the cell (see Section 5.4).

4.3 High Detector Output

Auto offset not activated recently



Offset

Press

Background not suppressed by SRS



Check the SRS regenerant out line for bubbles; if there are no bubbles, the
suppressor may be contaminated. Refer to the SRS manual for
troubleshooting guidanc e.

on the CD25 front panel before making an injection.

4.4 Noisy or Drifting Baseline

Flow system leak ahead of cell; erratic baseline



Check all fittings and liquid lines for leaks. Tighten or, if necessary, replace
all liquid line connections. If the connections are made with ferrule fittings,

Installation of Dionex Ferrule Fittings

4-2

first refer to
requirements.

Pump not properly primed



Prime the pump as instructed in the pump manual.

Rapid changes in ambient temperature



Redirect heating and air conditioning vents away from the cell.
Purchase a cell in a DS3 Detection Stabilizer (P/N 044130).
When using a shielded cell, install the cell in a chromatography oven.

for tightening

Doc. 031687-01 04/2000

4 • Troubleshooting

Insufficient system equilibration following any changes to operating



parameters; especially apparent when operating at high sensitivities

Allow longer system equilibration before beginning operation.

Air trapped in cell; excessive regular pulses in baseline



Remove the trapped air (see Section 5.2). To prevent air fro m becoming
trapped in the cell in the future, increase backpressure on the cell by reducing
the inner diameter of the tubing installed after the cell and before the SRS.

Inappropriate SRS operating conditions



Refer to the SRS manual for the correct operating conditions.

Temperature compensation setting not optimized



Optimize the selected setting (see Section 3.4).

DS3 above or below set point



See Section 4.6.

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4-3

CD25 Conductivity Detector

4.5 Liquid Leaks from the DS3

When a leak is detected, the DS3 leak sensor signals the CPU. If more than 5 mL
of liquid accumu lat es i n t h e DS3, the excess will be dr ained via the spill overflow
line (see Figure 2-6).

Loose or defective fittings, or overpressurization caused by a restriction



Check the waste line for blockage; a trapped particle can plug the line,
causing a restri ction and/or lea k. If necessar y , c lear the waste line by rever sing
the direction of flow.

Make sure the plumbing downst r eam f rom t he DS3 is clear; a blockage in the
plumbing may overpressurize the DS3, causing it to leak.

Make sure the downstream backpressure coils are appropriate for the
operating flow rate (see Section B.2.4).

Follow the steps below to disassemble the DS3 and inspect it for the source of
the leak. Test and dry the DS3 before reassembly.

1. Turn of f the CD25 power.

2. Disconnect the DS3 cables.

3. Disconnect the DS3 inlet and outlet lines. Do not misplace the ferrule
fittings at the end of the tubing (see Figure 4-1).

4. Remove the DS3 by lifting it upward and then pulling it away from its
mounting location. Place the DS3 on the workbench.

5. Open both latches on the DS3 and carefully lift off the top half of the
cover, along with its insulating foam insert, exposing an aluminum box
(see Figure 4-1).

6. Remove the box from the bottom half of the cover.

7. Remove the four Phillips screws securing the top of the box to its bottom
plate. Carefully separ at e t he t wo par ts , expos in g the cel l ( see Figure 4-2).
Lay the top aside, being careful not to pull or stress the group of wires that
connect the two parts.

8. Check the inlet and outlet cell fittings for leaks. Tighten or replace if
necessary.

9. Dry the DS3, test for leaks, and reassemble. Make sure the foam insert is
adjusted evenly aroun d the vari ous DS3 component s, with no pin ching or

4-4

Doc. 031687-01 04/2000

Bo tto m
Cover

4 • Troubleshooting

folding. Check that the top and bottom inserts meet on all sides before
latching the cover.

Ins u la t in g

Cables

Foam
Ins e rt

Aluminum
Box

Inle t

Outlet

Ph illips
Screws (4)

Sp ill Ov e rf lo w
Line

Figure 4-1. DS3 Exploded View

Inle t

Grounding Strap

Outlet

Cell

Outlet
Fitting

Inle t
Fitting

Figure 4-2. DS3 Interior Components

Top
Cover

Ph illi p s
Screws

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4-5

CD25 Conductivity Detector

Liquid seeping from around cell cables



The cell is inoperable; return it to Dionex for repair or exchange.

4.6 DS3 Temperature Inaccurate

“DS3 SET POINT XX C READY” message displays continuously



The control sensor may be faulty. Remove the DS3 cover and measure the
temperature of the housing, using any surface thermometer. The cell sensor
can be read on the detecto r and should be wi thin 1 or 2 de gre es of the DS3 set
point tempe r ature.

“DS3 SET POINT XX C UNDER TMP” or “DS3 SET POINT XX C



OVER TMP” message displays continuously

Verify that the set temperature is at least 5 °C above the external DS3
temperature. Allow 30 to 60 minutes for the DS3 to heat or cool.

At high flow rates and temperature settings far above ambient, the DS3
requires more time to heat. In extreme cases, such as a very cold room and a
high DS3 set point, the DS3 may not be able to reach the set point
temperature.

4-6

DS3 does not heat



Remove the cover and inspect the DS3 for broken or shorted wires or for
moisture bridging the control thermistor. If a wire is broken or shorted,
replace the wire or call Dionex for assistance. If a leak has caused a short, fix
the leak and dry the control sensor.

“DS3 SET POINT XX C READY” message displays intermittently



Make sure that the heater transistors are snug and the control sensor has not
been pulled out of the heat exchanger plate.

Doc. 031687-01 04/2000

4.7 Conductivity Inaccurate

4 • Troubleshooting

Cell constant reported on



calibration is not 130 to 190 µS

The DS3 has not reached its set point temperature. Set the intended operating
temperature and wait until 5 minutes after the “NOT READY” message is
displayed, or until the reading is stable.

Make sure the selected temperature compensation setting is 1.7%/°C. Except
at 25 °C, an incorrect temperature co mpensation set ting can caus e an incorrec t
reading.

The 1 mM KCl calibration solution is spoiled, or there was a mixing error.
Remake the solution.

The electrodes are fouled by grease, precipitate, etc. Flush with a suitable
solvent, such as acid, and then flush with 1 mM KCl until the reading is
stable.

The cause is internal leaks, broken or shorted cell or sensor wires. Check the
sensor by comparing the cell temperature readout with the actual DS3
temperature. If necessary, return the cell to Dionex for repair.

disassemble the cell; this will break the seal and v oid your warranty.
Cell temperature readout deviates by more than 2°C from DS3 set



temperature

This indicates a serious cell or DS3 sensor problem. Call Dionex for
assistance.

CONDUCTIVITY CALIBRATION

screen after cell

Do not

4.8 Faulty DX-LAN Communication

DX-LAN interface incorrectly install ed



See Section B.2.2 for 10BASE-T connection inst ructions or Section B.2.3 for
BNC connection instructions.

Doc. 031687-01 04/2000

4-7

CD25 Conductivity Detector

4.9 Diagnostics

NOTE The CD25 electronic components are not customer-

serviceable. Before running a diagnostic test, use the
troubleshooting information in earlier sections of
Chapter 4 to isolate problems that are unrelated to the
CD25 electronics.

The CD25 Moduleware includes several diagnostic tests of the electronics. To
access these, select the
diagnostic screens are illustrated and described in Appendix C.

DIAGNOSTIC MENU

from the

DIAG NOSTIC MENU

MENU of SCREENS

. The

POWER-UP SCREEN

1

ELAPSED TIME

2

ANALOG STATUS

3

-

4

DX LAN STATUS

5

KEYBOARD TEST

Help M essag e

Figure 4-3. Diagnostic Menu Screen

6

DIAG NOSTIC TESTS
LEAK CAL & STATUS

7
8

SIGNAL STATISTICS

9

CALIBRATE CD CELL

10

4-8

Doc. 031687-01 04/2000

5 • Service

This chapter describes routine service procedures that the user can perform. All
other procedures must be performed by Dionex personnel.

NOTE The CD25 electronics components are not customer-

serviceable. Repair of electronics components must be
performed by Dionex.

The CPU card contains a lithium battery. If the CPU card is
replaced, dispose of the used battery according to the
manufacturer's instructions.

Before replacing any parts, refer to th e troubleshooting information in Ch apter 4
to isolate the cause of the problem. To contact Dionex in the U.S., call 1-800-346­6390 and select the Technical Support option. Outside the U.S., call the nearest
Dionex office.

Substituting non-Dionex parts may impair CD25 performance, thereby voiding
the product warranty. Refer to the warranty statement in the Dionex Terms and
Conditions for more information.

Doc. 031687-01 04/2000

5-1

CD25 Conductivity Detector

5.1 Eliminating Liquid Leaks

The PEEK version of the CD25 is plumbed with 1.60-mm (1/16-in) OD PEEK
tubing, Dionex ferrule fittings (P/N 043276), and 10-32 fitting bolts (P/N

043275). For tightening requirements, refer to

Fittings

.

Installation of Dionex Ferrule

5.2 Removing Trapped Air from the Cell

Air bubbles in the cell can cause regular pulsations of the baseline, random
noise, and low r eadings. Ai r may have bee n intr oduced in the columns d uring
installation, or ma y result from outgassing of the mobi le phase. Connecting a
backpressure line to the cell applies enough backpressure to shrink bubbles,
thereby allow ing them to pass more easily through the cell.

1. Connect a piece of 0.25-mm (0.010-in) ID tubing (P/N 042690), with fittings
on both ends, to the cell outlet. Make the line 1 m long for a flow rate of

1.0 mL/min, 2 m for 0.5 mL/min, etc.

2. Use tubing with an inn er diameter of at least 1mm (0.04 in) t he rest of the way
to the waste containe r. Use a union (P/N 042627) to connect the backpres sur e
line to the w aste line.

Make sure the a dded backpres sure does not exceed 0.20 MPa
(30 psi). Avoid large increases in flow rate tha t would result in
more than 1.4 MPa (200 psi) being applied to the cell.

5.3 Replacing the DS3 Cell

Follow the steps below to disassemble the DS3 and replace the cell. After
replacing the cell you must recalibrate it (see Section 5.4).

1. Turn of f the CD25 power.

2. Disconnect the DS3 cables.

3. Disconnect the DS3 inlet and outlet lines. Do not misplace the ferrule fittings
at the end of the tubing (see Figure 5-1).

4. Remove the DS3 by lifting it upward and then pulling it away from its
mounting location. Place the DS3 on the workbench.

5-2

Doc. 031687-01 04/2000

5 • Service

5. Open both latches on the DS3 and carefully lift off the top half of the cover,
along with its insulating foam insert, exposing an aluminum box (see
Figure 4-1).

6. Remove the box from the bottom half of the cover.

7. Remove the four Phil lips screws securing the top of the box to its bottom
plate. Carefully sep arate the two par ts, exp osing t he cel l (see Figure 5-1). Lay
the top aside, bein g careful not to pull or stres s the grou p of wires t hat connec t
the two parts .

8. Disconnect the grounding strap. Remove the two cell mounting screws.

9. Rotate the cell inlet tube fitting counterclockwise. Let the cell body back
away from the fitting until the fitting threads are fully disengaged.

the ferrule

.

10. Check that the end of the inner Tefzel tubing is flush with the end of the
plastic sleeve. If nec essary, trim the sleeve slightly to prevent dis persion. Push
the tubing into the new cell until it bottoms out in the hole; then, hold the
tubing in place while tightening the nut.

11. After testing for liquid leaks, dry the DS3 and reassemble. Make sure the
foam insert is adjusted evenly around the various components, with no
pinching or folding. Before latching the cover, make sure the top and bottom
inserts meet on all sides.

Do not lose

12. Reconnect the DS3 cables and turn on the CD25 power. Calibrate the cell
constant (s ee Section 5.4).

Doc. 031687-01 04/2000

Inle t

Grounding Strap

Figure 5-1. DS3 Interior Components

Outlet

Cell

Outlet
Fitting

Inle t
Fitting

Ph illi p s
Screws

5-3

CD25 Conductivity Detector

5.4 Calibrating the Cell

Every conductivity cell is calibr ated be fore it is shi pped from the fa ctory. The cell
calibration constant is recorded on a tag attached to the cell cable, and is also
stored in permanent detector memory for use when calculating the measured
conductivity.

The calibration const ant normal ly rema ins uncha nged, unl ess the cell i s damaged.
To check the value entered in memory, select

DIAGNOSTIC MENU

cell calibration constant shown on the screen does not match the value recorded
on the tag, do



Enter a new value, regardless of the composition of the solution in the cell.



Calibrate the cell at 147.00 µS/cm. This automatically enters a new value for
the cell calibration constant into CD25 memory.

To calibrate the cell, follow the steps below.

1. Disconnect the pump output line from the injection valve.

2. Connect the pump output directly to the inlet of the DS3 or the shielded cell.

to display the

one

of the following:

CALIBRATE CD CELL

CALIBRATE CONDUCTIVITY CELL

from the

screen. If the

3. Pump 0.001 M KCl calibration solution through the cell. Conductivity is
slightly flow-rate sensitive , so select t he flow rate used in the majority of your
applications.

4. Set

TEMP COMP

on the

5. If using a DS3, set

DETAIL

DS3 SETPOINT

screen to 1.7%.

on the

DETAIL

screen to the intended

operating point. Wait until the “DS3 READY” message appears.

6. Wait until the conductivity reading st abili zes ( within 0 .1 µS), and then, on the

CALIBRATE CONDUCTIVITY CELL

screen, select

CAL

and press

Enter

to

calibrate the cell.

7. After calibration, t he conducti vity rea ding should b e exactly 14 7.00 µS/cm. A
new value for the cell constant will be shown on the

CONDUCTIVITY CELL

screen; thi s value will al so be entered in memory.

CALIBRATE

8. Flush the KCl solution from the system by pumping deionized water through
the DS3 or cell lines. When the conductivity reading drops to near zero, stop
the pump.

9. Disconnect the pump from the DS3 or shielded cell.

5-4

Doc. 031687-01 04/2000

5 • Service

10. Reconnect the pump to the chromatography module.

11. Reconnect the liquid line from the suppressor outlet to the cell inlet.

12. Reset

TEMP COMP

to the optima l value for the eluent.

13. S et the pump to a flow rate that is safe for the system in use.

Doc. 031687-01 04/2000

5-5

CD25 Conductivity Detector

5.5 Replacing the Main Power Fuses

The fuse holder is in the main power receptacle on the CD25 rear panel.

1. Turn of f the main power.

HIGH VOLTAGE—Disconnect the main power cord from its
source and also from the rear panel of the CD25.

2. A recessed lock is located on each side of the fuse holder (see Figure 5-2).
Using a small screwdriver, push each lock toward the center to rel eas e it . The
fuse holder pops out approximately slightly when the locks release. When
both locks are released, pull the fuse holder straight out of its compartment.

3. The holder contains two fuses. Replace both with new 3.15 amp fast-blow
IEC127 fuses (P/N 954745). Dionex recommends replacing both fuses even
though only one is open.

4. Reinsert the fuse holder into its compartment. The fuse holder is keyed to fit
only in its proper orientation. Apply sufficient pressure evenly against the
holder to engage the two locks. The holder is flush against the panel when
both locks are engaged.

5-6

5. Reconnect the main power cord and turn on the power.

Locking Spring

Fuse Holder

Insert screwdriver

and twist to release

(each side)

M a in Po we r
Receptacle

Figure 5-2. Main Power Fuse Holder

Fuses (2)

Key

Fuse Holder
(side vie w )

Doc. 031687-01 04/2000

5.6 Physical

A • Specifications

Dimensions

Weight

Decibel Level

A.1 Environmental

Operating

Temperature

Operating

Humidity

A.2 Electrical

Main Power

Fuses

22.5 cm W x 17.0 cm H x 42.0 cm D
(8.8 in W x 6.6 in H x 16.4 in D)
6 cm (2.4 in) clearance required behind the detector

8.2 kg (18 lb)
50 db (“A WEIGHING” setting)

4 ºC to 40 ºC (40 ºF to 104 ºF)

5 to 95% relative humidity, non-condensing

85 to 270 Vac, 47/63 Hz; 40 W Max, 25 W typical. The CD25
power supply is auto-sensing and requires no voltage
adjustment.

Two 3.15 amp fast-blow IEC127 fuses (P/N 954745)

Analog Ou tput

Doc. 031687-01 04/2000

User-selectable full-scale output of 10, 100, or 1000 mV

A-1

CD25 Conductivity Detector

A.3 Display and Keypad

Display

Keypad

Liquid crystal display with adjustable backlighting
26-button keypad for entering commands and numerical values

for screen parameters

A.4 Detector

Range

Temperature

Compensation

Cell Drive

Local Operation

Remote

Operation

DX-LAN

Operation

(Optional)

0.01 µS to 3000 µS, full-scale

0.0 to 3.0% per ºC

Variable 8 kHz square wave
Front panel controls and display status of all functions
Control of four functions via TTL or Relay contacts

All functions can be controlled by PeakNet software on a PC
connected to the CD25 via the DX-LAN interface

A.5 Conductivity Cell

A-2

Cell Body

Active Volume

Maximum

Pressure

Electrodes

PEEK

1.0 µL

2.0 MPa (300 psi)

316 stainless steel

Doc. 031687-01 04/2000

A.6 SRS Power Supply

A • Specifications

Supply Current

Over-Voltage

Alarm

Over-

Temperature

Alarm

50, 100, 300, 500 mA at 1.5 to 7.5 V

8.5 V

40 ºC (104 ºF)

A.7 DS3 Detection Stabilizer (Optional)

Operating

Temperature

Warm-up Time

Temperature

Alarms

25 ºC to 40 ºC (50 ºF to 104 ºF)

10 minutes (typical)

Not Ready

temperature

message displayed when under or over the set

Doc. 031687-01 04/2000

A-3

CD25 Conductivity Detector

A-4

Doc. 031687-01 04/2000

B.1 Facility Requirements



Make sure the CD25 installation site meets the el ectrical and environmental
specifications listed in Appendix A.



Install the CD25 on a sturdy table or workbench, at a height that ensures
convenient viewing of the front panel display.



Allow at least 6 cm (2.4 in) clear ance behind the CD25 for power con nections
and ventilation.

B.2 Installation

During installation, or whenever it is necessary to move the
detector, lift it o nly from the bottom or side. Lift ing the CD25 by
the front panel door will damage the door hinges.

B.2.1 Power Connection

The power to the CD25 can be controlled from the main power switch on
either the CD25 or the LC30 Chromatography Oven (i f prese nt). In eith er
case, no adjustment is required to select the line voltage.

B • Installation

For power on/of f contro l from the CD25, conn ect the modu lar power cord
(IEC 320 C13), from the main power receptacle on the rear panel (see
Figure B-1) to a grounded, single-phase, power source.

The power supply cord is used as the main disconnect device.
Ensure that the socket-outlet is located/installed near the
module and is easily accessible.

For power on/off control from the LC30 Chromatography Oven, connect
the IEC jumper power cord (P/N 960748) provided in the LC30 Ship Kit
from the main power recepta cle on the CD25 rear pane l to one of the four
IEC auxiliary receptacles on the rear panel of the LC30. Le ave the CD25
power switch on continuously and use the LC30 main power switch to

Doc. 031687-01 04/2000

B-1

CD25 Conductivity Detector

turn the CD25 on and off. Other modules in the system can be connected
to the LC30 in the same way, allowing the LC30 to function as the main
power source for the system.

SHOCK HAZARD—To avoid electrical shock, a grounded
receptacle must be used. Do not operate or connect to AC
power mains without an earthed ground connection.

Operation at AC input levels outside of the specified operating
voltage range may da mage the CD25.

DX-LAN

Connector

SAFETY WARNING

SERIAL NUMBER

DX-LAN

AND

LABEL

B-2

Chase

(TTL & Relay

Lines)

Fuse Holder

M a in P ow e r
Receptacle

Figure B-1. CD25 Rear Panel

Doc. 031687-01 04/2000

B • Installation

B.2.2 DX-LAN Interface: 10BASE-T Connections (Optional)

NOTE There are two types of DX-LAN connectors. Before

proceeding, check the CD25 rear panel. If a DX­LAN 10BASE-T RJ-45 (telephone-style) connector
is installed, follow the interface instructions in
Section B.2.2. However, if a DX-LAN 10BASE-2
BNC connector is installed, follow the interface
instructions in Section B.2.3.

In order to communicate with a host computer running Dionex
chromatography software, the CD25 must contain a detector interface
card (P/N 056798) and an unshielded twisted-pair DX-LAN cable
(P/N 960281) must be connected from the RJ-45 (10BASE-T) connector
on the rear panel to a “combo” 10BASE-T Ethernet hub (P/N 056909).

Installing or Replacing the Detector Interface Card

NOTE If the DX-LAN option was not installed at the

factory, order the detector interface card kit
(P/N 057007). The kit includes all the components
required for DX-LAN communication.

STATIC—The CD25 electronics cannot be serviced by the user.
The detector interface card must be installed by qualified
personnel. Standard anti-static procedures must be observed
when installing the interface card or handling the CPU card.

To prevent damage to the CD25, turn off the main power before
installing the detector interface card. After confirming that the
LED on the CPU card is off (not green or red), unplug the
power. Do not rely on the front panel power switch.

1. To replace an existing detector interface card, remove the DX-LAN

2. Remove any TTL/Relay plugs from the connectors at slot 4 of the

Doc. 031687-01 04/2000

cable from the 10BASE-T connector on the CD25 rear panel (see
Figure B-1).

electronics chassis (see Figure 2-5).

B-3

CD25 Conductivity Detector

3. Disconnect the 60-pin ribbon cable from the inside of the front panel
by opening the ejector latches on the connector.

4. Using a screwdriver as a lever, open the white ejector latch at the
bottom of the CPU card. Remov e the CPU card, cable, and Rel ay card
as a single unit.

5. Remove the detector interface card (if present) from slot 4 of the
electronics chassis.

6. Insert the new detector interface card (P/N 056798) into slot 4:
a. Slide the card to the rear.
b. Verify that the 10BASE-T connector is aligned with the opening

at the rear and that the card is aligned with the card connector.

c. Press firmly on the card until it mat es f ul ly wi th the connector on

the rear panel. Pull on the card to verify that it cannot move.

7. Reinstall the CPU/Relay card. Press firmly until the card is inserted
into the connector on the rear panel.

8. Reconnect the ribbon cable to the 60-pin connector on the inside of
the front panel. The header and connector are key-polarized near the
center . Th e ejector latches should be pa rtiall y open to ac cept the c able
connector.

B-4

9. Install the 10BASE-T DX-LA N cable (see the following sec t ion).

Installing the 10BASE-T DX-LAN Cable

1. Install the “combo” 10BASE-T Ethernet hub (P/N 056909) on a
workbench or on the wall. For installation instructions and site
requirements, refer to the installation guide shipped with the hu b.

2. Plug the 10BASE-T DX-LAN cable (P/N 960281) into a 10BASE-T
port on the front panel of the hub.

The 10BASE-T DX-LAN cable is a Category 5 unshielded
twisted-pair cable. Do not substitute a cable of an inferior
grade. Failure to use the correct cable will cause the detector
to lose communication with the host computer.

3. Connect the other end of the cable into the 10BASE-T DX-LAN
connector on the CD25 rear panel (see Figure B-1).

Doc. 031687-01 04/2000

B • Installation

4. Connect a 10BASE-T cable (P/N 960281) from a 10BASE-T port on
the hub to the 10BASE-T port on the host computer’s in ternal DX-
LAN card. If the connection is via port 8 on the hub, set the
Normal/Uplink push button to Normal.

NOTE Installation instructions for the host computer’s

internal DX-LAN card are in

Peak N et 6 System

When using 10BASE-T cabling, you must use a hub. If you
simply plug the 10BASE-T cable from the detector into the
connector on the host computer’s DX-LAN card, the
connection will either not work or will be unreliable.

Network Upgrades

(Document No. 031631).

If you upgrade the network from a BNC connector to a 10BASE-T
connector, turn of f the computer po wer briefly and then turn it on aga in to
allow the host computer’s internal Ethernet DX-LAN card to detect the
10BASE-T con nec tor. The Ethernet card searches for th e t ype of i nstal led
cabling only at power-up.

Installing the Dionex

Cascading Hubs

Cascading, or connecting hubs together through their 10BASE-T ports,
increases the number of ports or the number of users supported on the
network. For instructions, refer to the installation guide for the hub.

Doc. 031687-01 04/2000

B-5

CD25 Conductivity Detector

B.2.3 DX-LAN Inte rface: BNC Connections (Optional)

NOTE There are two types of DX-LAN connectors. Before

proceeding, check the CD25 rear panel. If a DX­LAN 10BASE-2 BNC connector is installed, follow
the interface instructions in Section B.2.3. However,
if a DX-LAN 10BASE-T RJ-45 (telephone-style)
connector is installed, go on to Section B.2.2.

In order to communicate with a host computer running Dionex
chromatography software, the CD25 must contain a detector interface
card (P/N 046341) and a coaxial DX-LAN cable (P/N 960405) must be
connected to the BNC tee connector (P/N 921914) on the rear panel.
From the CD25, connect the DX-LAN cable to one of the following:

Another instrument equipped with a BNC connector,



A “combo” 10BASE-T Ethernet hub (P/N 056909). The hub has one



BNC port and eight 10BASE-T (RJ-45) ports.

Installing or Replacing the Detector Interface Card

or

B-6

NOTE If the DX-LAN option was not installed at the

factory, order the detector interface card kit
(P/N 044195). The kit includes the components
required for DX-LAN communication.

STATIC—The CD25 electronics cannot be serviced by the user.
The detector interface card must be installed by qualified
personnel. Standard anti-static procedures must be observed
when installing the interface card or handling the CPU card.

To prevent damage to the CD25, turn off the main power befor e
installing the detector interface card. After confirming that the
LED on the CPU card is off (not green or red), unplug the
power. Do not rely on the front panel power switch.

1. To replace an existing detector interface card, remove the hex nut
securing the DX-LAN BNC connector to the CD25 rear panel (see
Figure B-1).

Doc. 031687-01 04/2000

B • Installation

2. Remove any TTL/Relay plugs from the connectors at slot 4 of the
electronics chassis (see Figure 2-5).

3. Disconnect the 60-pin ribbon cable from the inside of the front panel
by opening the ejector latches on the connector.

4. Using a screwdriver as a lever, open the white ejector latch at the
bottom of the CPU card. Remov e the CPU card, cable, and Rel ay card
as a single unit.

5. Remove the detector interface card (if present) from slot 4 of the
electronics chassis.

6. Insert the new detector interface card (P/N 046341) into slot 4:
a. Slide the card to the rear.
b. Verify that the BNC connector is aligned with the opening at the

rear and that the card is aligned with the card connector.

c. Press firmly on the card until it mates fully with the connector on

the rear panel. Pull on the card to verify that it cannot move.

7. Reinstall the CPU/Relay card. Press firmly until the card is inserted
into the connector on the rear panel.

8. Reconnect the ribbon cable to the 60-pin connector on the inside of

9. Install the hex nut, BNC tee connector, and coaxial DX-LAN cable

Installing the BNC Tee Connector and Coaxial DX-LAN Cable

1. Install the BNC tee connector (P/N 921914):

2. Install the coaxial DX-LAN cable (P/N 960405):

Doc. 031687-01 04/2000

the front panel. The header and connector are key-polarized near the
center. The ejector latches must be partially open to accept the cable
connector.

(see the following section).

a. Note the two small locking pins on either side of the DX-LAN

BNC connector on the rear panel (see Figure B-1).

b. Push the tee connector onto the BNC connector on the rear panel

and twist until the locking pins are fully engaged in the slots on
the tee connector.

c. Pull firmly on the tee connector to verify that it cannot move.

B-7

CD25 Conductivity Detector

a. Push the metal sleeve on the end of the DX-LAN cable onto one

port of the BNC tee connector.

b. Twist the metal sleeve until the locking pins on the tee are fully

engaged in the slots on the cable's metal sleeve.

c. Pull the end of the cable to verify that it cannot move.

The DX-LAN cable (P/N 960405) is a 50 ohm coaxial impedance
cable. (Fifty ohm cables are imprinted with “RG-58U.”) Do not
substitute cables. Failure to use the correct cable or to lock it
into place on the BNC connector will cause the CD25 to lose
communication with the host computer.

3. If the CD25 is the last module in the network to be connected, install
a terminator resistor plug (P/N 921034) on the remaining port of the
BNC tee connector. (These terminator resistor p lug s a re shipped with
Dionex chromatography software.)

If the CD25 is not the last module in the network, connect the cable
from the next module to the BNC tee.

4. Plug the free end of the coaxial DX-LAN cable into one of these:

The BNC connector on another instrument,



The BNC port on the rear panel of the “combo” 10BASE-T



or

Ethernet hub (P/N 056909).

If the connection terminates at the hub, install a BNC terminator
(included with the hub) on the BNC tee connector.

50 Ohm terminator resistor plugs must be installed at each end
of the DX-LAN network. Before beginning operation, verify that
both ends of the DX-LAN have terminator resistor plugs
installed.

B-8

Doc. 031687-01 04/2000

B.2.4 DS3 Detection Stabilizer Installation

Install the DS3 with the conductivity cell (P/N 044130) in a
chromatography module—for example, an LC20 Chromatography
Enclosure—or on a laboratory workbench. The instructions for installing
the DS3 vary somewhat, depending on the type of enclosure. See
Section B.2.6 for in stallation and plumbing instructions.

NOTE To install a DS3 or shielded cell in an AS50

autosampler chromatography compartment or
oven, refer to the AS50 operator’s manual.

B.2.5 Shielded Conductivity Cell Installation

The installation instructions for the shielded conductivity cell (P/N

044132) are the same as for the DS3, exc ept that the shie lded cell does not
have a heater power cord.

B.2.6 DS3 or Shielded Cell Plumbing

B • Installation

The DS3 or shielded cell can be plumbed for three operating modes:



AutoSuppression™ Recycle mode (SRS required), shown in
Figure B-2.



AutoSuppr ession with External Regen erant mode (SRS required ),
shown in Figure B-3. Also plumb the system in this way for the
AutoSuppression Chemical Suppressor and MMS Pressurized Regen
System configurations.



Nonsuppressed mode, shown in Figure B-4. Note that conductivity
measurements made when no suppressor is in-line may show
noticeable baseline drift.

Doc. 031687-01 04/2000

B-9

CD25 Conductivity Detector

The CD25 Ship Kit includes certain items required when installing the
SRS:



SRS gas separator waste tube (P/N 045460)



Backpressure coil for 4 mm SRS (P/N 045877)



SRS-to-CD25/ED50 control cable (P/N 046346)

NOTE The instructions here do not replace the inst ructions

in your SRS manual. For detailed SRS installatio n
instructions, and for the initial start-up procedure
that must be performed before you begin routine
operation, please refer to the SRS manual.

Backpressure Requirements

Detector cells req uire enoug h backpr essure t o prevent mobile p hase in th e
cell from degassing due to abrupt volume changes between the small
inner diameter of the connecting tubing and the larger volume of the cell.
Degassing creates bubbles in the cell and disrupts detector
responsiveness.

Before plumbing a system f or th e Aut oSupp ression mode, check the SRS
manual for backpressure requirements.

NOTE The backpressure generated by the DS3, cell, and

backpressure tubing is applied to the SRS. For
example, with 1 meter of 0.25-mm (0.01-in) ID
tubing at a flow rate of 1.0 mL/min, the
backpressure is about 200 kPa (30 psi).

B-10

Doc. 031687-01 04/2000

B • Installation

For backpressure requirements for the Nonsuppressed mode, see the
following table. The minimum backpressure should be 0.21 to 0.34 MPa
(30 to 50 psi) per minute.

Flow Rate (mL/min) Tubing ID Coil Length Number of

Coils

0.5 to 1.5 0.25-cm
(0.010-in)

1.5 to 3.0 0.25-cm
(0.010-in)

0.12 to 0.37 0.12-cm
(0.005-in)

0.37 to 0.75 0.12-cm
(0.005-in)

Table B-1. Coils for Backpressure Requirements (Nonsuppressed Mode)

0.76 M
(2.5 feet)

0.76 M
(2.5 feet)

0.30 M
(1.0 feet)

0.30 M
(1.0 feet)

2

1

2

1

Doc. 031687-01 04/2000

B-11

CD25 Conductivity Detector

Injection
Valve

Guard
Column

Analytical Column

2 mm ID, 10-32, 0.005" ID PEEK Liquid Line
4 mm ID, 10-32, 0.010" ID PEEK Liquid Line
4 mm ID, 1/4-28, 0.012" ID Tefzel Liquid Line

REGEN OUT

ELUENT IN

10-32

1/4-28

Waste

ANION SELF-RE GENER ATING
SU P PR E S S OR 4 mm
P/N 043189 S /N XXX X

1/4-28

1/4-28

ELUENT OUT

10-32

REGE N IN

1/4-28

Gas

Separator

Waste

Tube

1/4-28

10-32

10-32 or
1/4-28

10-32

10-32

10-32

Coil

#2

10-32 or

1/4-28

Coil

#1

Cell

10-32 or
1/4-28

Signal to
Detector

B-12

Figure B-2. AutoSuppression Recycle Mode

Doc. 031687-01 04/2000

Inje ctio n
Valv e

Guard
Colum n

Analytical Column

2 m m ID, 10-32, 0.005" ID PEE K L iquid Line
4 mm ID , 10-32, 0.010" ID PEE K Liquid Line
4 mm ID , 1/4-28, 0.012" ID Tefzel Liquid Line

0.02 0" I D
Tefzel

REGEN OUT

ELUENT IN

10-32

1/4-28

1/4-28

1/4-28

Waste

ANION SELF-REGENERATING
SUPPRESSOR 4 mm
P/N XXXXXX S/N XXXX

Separator

ELUENT OUT

10-32

REGEN IN

1/4-28

Gas

Waste

Tube

D eionized
Water Source

10-32 or
1/4-28

B • Installation

To
Waste

1/4-28

10-32

Coil

#2

10-32

10-32

Coil

#1

10-32

10-32 or

Cell

S ig n al to
C o n du c tiv ity
D etector

10-32 or
1/4-28

1/4-2 8

Figure B-3. AutoSuppression Mode, External Regenerant

Doc. 031687-01 04/2000

B-13

CD25 Conductivity Detector

Injection
Valve

Analytical Column

2 mm ID, 10-32, 0.005" ID P E EK L iquid Line
4 mm ID, 10-32, 0.010" ID PEEK Liquid Line
4 mm ID, 1/4-28, 0.012" ID Tefzel Liquid Line

Guard
Column

DS3

Figure B-4. Nonsuppressed Mode

Backpressure Coils

Waste

To

B-14

Doc. 031687-01 04/2000

DS3 Detection
Stabilizer
(or Shielded
Conductivity Cell)

Alternate DS3 or
Shielded
Conductivity Cell
Location

B • Installation

SRS

Doc. 031687-01 04/2000

FRONT

Figure B-5. Typical DS3 Installation in LC20 or LC30

B-15

CD25 Conductivity Detector

Installing a DS3 or Shielded Cell in an LC20, LC25, or LC30

1. Position the keyhole slots on the rear of the DS3 or cell over the
shoulder washers on the LC20, LC25, or LC30 component mounting
panel, then pull the DS3 or cell down into position.

2. Route the DS3 or cell cables out the hole located at the back of the
LC20, LC25, or LC30 and into the cable chase at the base of the
detector. Next, route the cables through the cable chas e to the fr ont of
the detector. (You can also route the cables into the detector through
the slots on the sides of the detecto r.)

3. Plug the connectors on the cables into the appropriate jacks on the
SCR card. (To identify the card location and connector positions, see
the label on the inside of the CD25 front door or to Figure 2-5 in this
manual.)

4. Connect the eluent outlet of the column or suppressor to the DS3 or
cell inlet, using 0.25-mm (0.010-in) ID tubing (P/N 042690), 10-32
fittings (P/N 043275), and ferrules (P/N 043276).

5. Connect the outlet of the DS3 or cell to either the SRS REGEN IN
port (for AutoSuppression Recycle mode) or to the backpressure line
leading to waste (for AutoSuppression with External Regenerant
mode or Nonsuppressed mode).

B-16

6. Direct the spill/overflow tubing to the spill tray at the bottom front of
the LC20, LC25, or LC30.

Installing a DS3 or Shielded Cell in an LC10

1. If installing a DS3, cut the spill/overflow tubing within 2.0 cm (3/4
in) of the DS3 enclosure.

2. Position the keyhole slots on the rear of the DS3 or cell over the
shoulder washers located on the LC10. Push the DS3 or cell down to
secure it in place.

3. Route both DS3 or cell cables through the hole located at the base of
the detector cable chase. Next, route the cables through the cable
chase to the front of the detector. (You can also route the cables into
the detector using the slots on the sides of the detector.)

Doc. 031687-01 04/2000

4. Plug the connectors into the appropriate jacks on the SCR card. (To
identify the card l ocation and co nnector pos itions, se e the label on the
inside of the CD25 front door or to Figure 2-5 in this manual.)

5. Connect the eluent outlet of the column or suppressor to the DS3 or
cell inlet, using 0.25-mm (0.010-in) ID PEEK tubing (P/N 042690),
10-32 fittings (P/N 043275), and ferrules (P/N 043276). See Table B­1 for backpressure requirements.

6. Connect the outlet of the DS3 or cell (the 10-32 coupler) to the SRS
REGEN IN port (for AutoSuppression Recycle mode) or to the
backpressure line leading to waste (for AutoSuppression with
External Regenerant mode or Nonsuppressed mode).

B.2.7 Recorder/Diagnostic Connection

Connecting a strip chart recorder or integrator to the CD25 lets you record
or monitor several parameters besides the cell analog output. For the
recorder/diagnostic signal cable pinouts, see Table E-1 in Appendix E.

Use the twisted black and red wires (P/N 043598) provided in the CD25
Ship Kit to connect a recorder or integrator to the SCR card in the
electronics chassis. Strip the ends of the wires and insert into the plugs;
the signal wire (red) goes on the top of each plug and the ground wire
(black) goes on the bottom. Tighten the locking screws with the
screwdriver (P/N 046985) provided in the CD25 Ship Kit.

B • Installation

Doc. 031687-01 04/2000

B-17

CD25 Conductivity Detector

B.3 Automatic SRS Power Control (Optional)

TTL connections can be used to automatically switch off the power to a Self­Regenerating Suppressor (SRS) when the flow from the pump stops.

1. On the

PUMP OPTIONS

screen, set

TTL2 OUTPUT USAGE

to

0 Flow

. (For more
details, see the operator's manual for the GP50 Gradient Pump or IP25
Isocratic Pump.)

2. On the CD25

TTL FUNCTION IN

screen, assign

TTL3

SRS OFF/ON

to

.

3. Locate the twisted black and red wires (P/N 043598) and two green TTL
connector plugs (P/N 921019) provided in the CD25 Ship Kit.

4. Strip the ends of the wires and insert them into the plu gs, wit h t he si gna l wir e
(red) on top of each plug and the ground wire (black) on the bottom. Tighten
the locking screws with the screwdriver (P/N 046985) provided in the CD25
Ship Kit.

5. Plug one end of the cable into TTL2 OUT on the pump (see Figure B-6).

6. Route the cable through the upper chase of the pump and the CD25, and then
plug the free end of the cable into TTL3 IN on the CD25.

7. Turn of f the flow (f rom the pump) and confirm tha t the detect or automat ically
turns off the SRS. First, however, expect a 5-minute delay from the ti me the
CD25 receives the signal until the power to the SR S is turned off; this delay
allows momentary flow interruptions without disturbing the SRS.

B-18

Doc. 031687-01 04/2000

B • Installation

Doc. 031687-01 04/2000

Figure B-6. TTL Connections for SRS Power Control

B-19

CD25 Conductivity Detector

B-20

Doc. 031687-01 04/2000

C • User Interface

This appendix illustrates and describes all of the screens available for display on
the front panel of the CD25 Conductivity Detector. There are two categories of
screens: operational and diagnostic.



Operational

CD25 operation, and to select default parameters for the detector.



Diagnostic

including some screens that enable you to calibrate various CD25 functions.

Operational Screens

123 5678

MAIN

SCREEN

screens enable you to create, edit, and run methods that control

screens provide access to diagnostic information and tests,

MENU of

SCREENS

DETAIL

SCREEN

METHOD

MODULE

SETUP

ANALOG OUT
SETUP

FUNCTION IN

TIME

DIAGNOSTIC

MENU

Diagnostic Screens

123 5678

POWER-UP

SCREEN

ELAPSED

Doc. 031687-01 04/2000

TIME

METHOD

EXTENSION

4

ANALOG
STATUS

DX LAN

STATUS

KEYBOARD

TEST

DIAGNOSTIC
TESTS

Figure C-1. CD25 Menu Structure

LEAK CAL
& STATUS

SIGNAL
STATISTICS

9

CALIBRATE
CD CELL

C-1

CD25 Conductivity Detector

C.1 Operational Screens

C.1.1 Menu of Screens

MENU of SCREENS

The

MENU of SCREENS

1

MAIN SCREEN

2

DETAIL SCREEN

3

METHOD

4

- - -

Help Message

Figure C-2. Menu of Screens

There are two ways to select a screen from this men u:

provides top-level access to the menu structure.

MOD ULE SETUP

5

ANALOG OUT SETUP

6
7

TIM E FUNCTION IN

8

DIA GNOSTIC MENU



Use the cursor arrow buttons to move the cursor to the field
containing the screen number and press



Press the number b utton on t he front pa nel keypa d that co rresp onds to

Enter

.

the screen.

To display a brief description of each menu option, press the

Help

button.

C-2

Doc. 031687-01 04/2000

C.1.2 Main Screen

MAIN

The
primary functions in large characters to make viewing easier from a
distance.

screen displays the measured conductivity (siemens) and other

C • User Interface

TOTA L 13 8 .7 1 u S

+2. 34

LOCAL

Help M essage

Screen Field Description
TOTAL

SRS

RANGE

LOCAL/ REMOTE

Displays total conductivity (without an offset).
Selects the amount of current sent to the suppressor . Current selection

depends on the eluent concentration, flow rate, etc. The discrete
settings are Off, 50, 100, 300, and 500 mA.

Sets the analog output scale factor. Select a range between 0.01 and
3000 µS.

Local mode is used for front panel control. The CD25 will
automatically switch to Locked Remote mode when a Connect
command is given from PeakNet 6. Locked Remote mode prevents
operation from the keypad. The Locked Remote mode can be
canceled only by a Disconnect command from PeakNet 6 or by
turning off the CD25 and then turning it back on.
does not use the regular (unlocked) Remote mode.

METHOD 05

Figure C-3. Main Screen

uS

SRS

RANGE

50

1000 uS

Note:

PeakNet 6

DIRECT
CONTROL/
METHOD

Doc. 031687-01 04/2000

Select

Press either
Method operating modes.

button to toggle between the Direct Control and

C-3

CD25 Conductivity Detector

C.1.3 Detail Screen

DETAIL

The

screen includes all the f ields cont ained on the

well as the TTL and Relay fields and fields to control detection. Refer to

MAIN

the

screen for a description of fields that are common to both

screens.

D E TA IL SCREEN
OUTPUT

128.2

O F F SET 58 .7nAnA

TOTAL

184.9 nA

pH 12.2

POTENTIAL

Help Mess a g e

Figure C-4. Detail Screen

Screen Field Description
TEMP COMP

DS3 SETPOINT
TTL1

TTL2

Sets the temperature compensation factor. The range is 0 to 3%.

1.7% is appropriate for most eluents.
Sets the temperature of the DS3 Detection Stabilizer.
Provides TTL control of accessories. In a method, these values

occur according to the method timing. In Direct control, select off
(0) or on (1).

DC AMPERO METRY

CELL

RANGE

REF

ON
200 nA
Ag

+0.80V

123.45 MINLOC AL ME THOD 05

MAIN

TTL1
TTL2

RLY1
RLY200

screen, as

1
1

C-4

RLY1
RLY2

Provides relay contact closure control of accessories. In a method,
these values occur according to the method timing. In Direct co ntrol,
select off (0) or on (1).

Doc. 031687-01 04/2000

C.1.4 Method

A method consists of a series of timed steps. Each step has a set of
parameters associated with it.

Initial conditions are applied when a method is invoked. A lower case
next to the la st step on the d isplay i ndicates that t he method contains more
steps.

Blank fields denote no change from the previous step. The
blanks the fie ld.

C • User Interface

v

Delete

button

NOTE

TEMP COMP, DS3 TEMP

time-programmable.

METHOD EDIT SAVE TO

TEMP COMP

TIME

RANGE

INIT

1.6

200 uS

0.00
v

2.00

Help M essag e

Figure C-5. Method Screen

Screen Field Description
EDIT

SAVE TO

RUN

Specifies the method number (1 through 99) to edit.

Note:

Method number 0 is reserved for methods downloaded from

PeakNet 5.2 (or later), for remote control of the CD25.
Specifies the method number (1 through 99) to save the current

method to.
Specifies the method number (1 through 99) to run. The

button controls the running of the method.

SRS CURRENT

, and

3333

TTL RLY

OFFSET MARK

1
0

**

1

are not

RUN

25

SRS 100DS3 TEMP 40

212
000

1

Hold/Run

TEMP COMP
SET TEMP
SRS

Doc. 031687-01 04/2000

Sets the Temperature Compensation factor.
Sets the temperature for the DS3 Detection Stabilizer.
Sets the Self-Regenerating Suppressor current.

C-5

CD25 Conductivity Detector

Screen Field Description
TIME

RANGE
OFFSET

MARK

TTL
RLY

Specifies the start time for each step. Times are displayed
chronologically.

Sets the analog output range.
Stores the offset value. The baseline is set by subtracting the offset

measured when this step is executed from all subsequent
measurements. An asterisk (*) indicates that OFFSET will occur at
this time.

Sends a positive pulse to the analog output (recorder) as an event
marker. An asterisk (*) indicates that a MARK will occur at this
time.

Sets TTL1 and TTL2 to off (0) or on (1).
Sets RLY1 and RLY2 to off (0) or on (1).

C-6

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C.1.5 Module Setup

The backlight intensity, key beep, and error beep are configured from the

MODULE SETUP

C • User Interface

screen.

MODULE SETUP

DISPLAY PANEL BACKLIGHT:

KEY ACTUATION SOUND:

ENTRY ERROR SOUND:

Help Message

Figure C-6. Module Setup Screen

Screen Field Description
DISPLAY PANEL

BACKLIGHT
KEY ACTUATION

SOUND
ENTRY ERROR

SOUND

Sets the display panel backlight to

OFF

.

Toggles the keypad touch sound. When this option is selected ,
the detector sounds a beep when a button is pressed.

Toggles the error sound. When this option is selected, the
detector sounds a beep when an invalid entry is made.

MEDIUM
ON
ON

LOW, MEDIUM, HIGH

, or

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C-7

CD25 Conductivity Detector

C.1.6 Analog Out Setup

ANALOG OUT SETUP

The
analog output, such as for a recorder or oscilloscope.

ANALOG O UT SETUP

OUTPUT:

ZERO POSITION :

VOLTS FULL SCALE:

RISE TIME:

POLARITY:

Help Message

Figure C-7. Analog Out Setup Screen

Screen Field Description

screen contains parameters for setting the

OFFSET

10

% FULL SCALE
V

1.0

1.0

sec

+

OUTPUT

ZERO POSITION
VOLTS FULL

SCALE
RISE TIME

POLARITY

Sets the analog output to one of the following:

OFFSET
TOTAL

uses the offset level value.

sets the detector output to the total cell conductivity, charge

or current, disabling the offset function.

ZERO

sets the detector output to zero volts.

FULL SCALE

sets the output to the full-scale setting.
Sets the analog (recorder) offset level (0 to 100%).
Sets the full-scale voltage for a signal equal to the range setting. The

discrete settings are 1.0, 0.1, and 0.01 volts.
Sets the ou tput filter r ise time to 0.05, 0.1, 0.2, 0.5, 1.0, 2. 0, 5.0, or

10.0 seconds. Rise time is a measure of how quickly the detector
goes from 10% to 90% of step input changes. A digital filter is used
with zero undershoot or overshoot for minimal peak distortion.

Determines the output voltage polarity. The output is usually set to
positive polarity. Negative polarity is used to reverse peaks from
indirect detection.

C-8

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C.1.7 Time Function In

This screen displays the detector functions that can be controlled with
TTL input from another device and lets you assign any four of the
functions to the fo ur TTL inputs. Th e
signal the detector will respond to. The signal type can be changed to
match the signal of the controlling device. See Section D.3 for details.

Select

Use the
TTL1 through TTL4 to any four of the functions.

buttons to select the TTL input signal mode and to assign

C • User Interface

MODE

field selects th e type of input

TIME FUN CTION IN

OFFSET:

HOLD/RUN:

SRS

METHOD NUMBER INCR:

Help M essage

ON/OFF:

RANGEx10:

Figure C-8. Time Function In Screen

MODE: NORMAL EDGE

MARK:

TTL
TTL
TTL
TTL
TTL
TTL

1
2
3

DECR: -

4

-

-

TTL

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C-9

CD25 Conductivity Detector

C.2 Diagnostic Screens

To access the CD25 diagnostics, select the

SCREENS

returns you to the

Menu

. While a diagnostic screen is displayed, pressing the

DIAGNOSTIC MENU

returns you to the

MENU of SCREENS

. From the

C.2.1 Diagnostic Menu

Figure C-9 shows the
explained in detail in the following sections.

POWER-UP SCREEN

1

ELAPSED TIME

2

ANALOG STATUS

3

-

DX LAN STATUS

4
5

KEYBOARD TEST

Help M essag e

Figure C-9. Diagnostic Menu Screen

There are two ways to select a screen from this men u:

DIAGNOSTIC MENU

DIAG NOSTIC MENU

6
7
8
9

10

DIAGNOSTIC MENU

DIAGNOSTIC MENU

.

. The nine menu options are

DIAG NOSTIC TESTS
LEAK CAL & STATUS

SIGNAL STATISTIC S
CALIBRATE CD CELL

from the

Menu

button

, pressing

MENU of

C-10



Use the cursor arrow buttons to move the cursor to the field
containing the screen number and press



Press the number b utton on t he front pa nel keypa d that co rresp onds to

Enter

.

the screen.

To display a brief description of each menu option, press the

Help

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button.

C.2.2 Power-Up Screen

POWER-UP

The
and BIOS code. It also displays the identification number of the optional
DX-LAN interface, if co nnected.

screen displays the revi sion nu mbers fo r the Module war e

CD25 CONDUCTIVITY DETECTOR

C • User Interface

Help M essag e

MODULEWARE REV

BIOS REV n.nn

Figure C-10. Power-Up Screen

n.nn
nnnnnnDX L-AN ID#

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C-11

CD25 Conductivity Detector

C.2.3 Elapsed Time

This screen reports for how long various CD25 parameters have been in
use. The status of each parameter updates in real time.

MODULE ON:

BACKLIGHT:

SRS ON:

CD CELL ON:

Help M essag e

Figure C-11. Elapsed Time Screen

Screen Field Description

ELAPSED TIME

nnnnnn hours
nnnnnn hours
nnnnnn hours
nnnnnn hours

RESET

*
*

MODULE ON

BACKLIGHT

SRS ON

CD CELL ON

RESET

Reports the total time the detector has been powered up in its
lifetime.

Reports the total time the LCD backlight has been on in its
lifetime.

Reports the total time the SRS has run. Reset this field to zero
after changing the SRS.

Reports the total time the conductivity cell has run. Reset thi s
field to zero after replacing the cell.

Allows a timer to be reset to zero to restart the counter. Reset the
appropriate timer after installing a new component.

C-12

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C.2.4 Analog Status

This screen reports the status of several analog test points. If a run is in
progress, the status updates are from the last idle state. If no run is in
progress, the values are in real time.

SRS CONNECTED:
SRS OVER TEMP:
SRS OVER VOLT:

THERMISTO R TEM PERATURE: nn.n Degrees

Help M essage

Figure C-12. Analog Status Screen

Screen Field Description

ANALOG STATUS

Y
N
N

DS3 CONNECTED:
DS3 OVER TEMP:
DS3 UNDER TEMP:

CD CELL CONNECTED:

C • User Interface

Y
N
N
N

SRS CONNECTED

SRS OVER TEMP
SRS OVER VOLT
DS3 CONNECTED

DS3 OVER TEMP
DS3 UNDER

TEMP
CD CELL

CONNECTED
THERMISTOR

TEMPERATURE

Indicates whether a Self-Regenerating Suppressor is connected
to the detector.

Indicates whether the SRS is over the temperature specified.
Indicates whether the SRS is over the voltage range specified.
Indicates whether a DS3 Detection Stabilizer is co nnected to the

detector.
Indicates whether the DS3 is over the temperature specified.
Indicates whether the DS3 is under the temperature specified.

Indicates whether a conductivity cell is connected to the
detector.

Indicates the temperature recorded from the conductivity cell
thermistor.

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C-13

CD25 Conductivity Detector

C.2.5 DX-LAN Sta tus

The DX-LAN driver monitors several types of erro rs that may occur on
the network. The detector reads the DX-LAN error counts and displays
them on this screen, alo ng with the DX-LAN addresses. Most errors are
caused by a defective cable, missing or incorrec tly terminated cable. The
coaxial DX-LAN cable must be RG58U or RG58AU.

UNIQUE DX- LAN ID:

-

DX LAN ADDRESS:

-

DX LAN

STATUS
FF FF FF FF
FF FF FF FF FF FF

COLLISION:

B U S WRIT E :

UNDERFLOW:

nnn
nnn
nnn

ALIGNMENT:

OVER FLOW:

Help Message

Figure C-13. DX-LAN Status Screen

Screen Field Description
UNIQUE DX-LAN

ID

DX-LAN
ADDRESS

COLLISION

BUS WRITE

UNDERFLOW

Displays the three-byte DX-LAN ID programmed into the
detector Moduleware (in HEX). The ID is unique to the detector
and never changes.

Displays the six-byte DX-LAN address assigned by the PC (in
HEX). The first three bytes are the system assignment and the
last three bytes are the assignment within the system.

Indicates that 16 unsuccessful transmissions of the same packet
occurred, due to collisions.

Indicates that a ready response could not be issued within 2.4
microseconds after the WR signal was asserted. This occurs
when the transmit buffer memory is full.

Indicates that data from the transmit section of the hardware
buffer memory is not available for serial transmission. The DX­LAN will continue to send out this data frame.

BUS READ:

nnn
nnn
nnn

CRC:

RUNT:

RETRY:

nnn
nnn
nnn

C-14

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Screen Field Description

C • User Interface

ALIGNMENT

BUS READ

OVERFLOW

CRC

RUNT

RETRY

Indicates that a packet was received with an alignment error,
meaning that there were one to seven extra bits at the end of the
packet. This is usually caused by a collision or a faulty
transceiver.

Indicates that a ready response could not be issued within 2.4
microseconds after the ready signal was asserted. This occurs
when reading an empty buffer.

Indicates that the DX-LAN hardware receive buffer became full
and had to reject a packet for lack of space.

Indicates that a packet was received with a CRC error. This
usually means that a collision has corrupted the packet.

Indicates that a “runt” packet (one less than 15 bytes in length)
was received. This usually occurs after a collision has truncated
the original length.

Indicates the number of retries required to transmit the last
packet.

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C-15

CD25 Conductivity Detector

C.2.6 Keyboard Test

You can conduct an interactive test of the CD25 front panel keypad from
this screen. Pressing any front panel button changes the corresponding
button indicator on the screen to reverse video. This confirms proper
operation of that button. When you release the button, the display returns
to normal video.

OFFSET
MARK
INSERT
DELETE

Help Message

RUN/HOLD
RESET
SEL UP
SEL DOWN

Figure C-14. Keyboard Test Screen

UP 7 8 9

LEFT RIG HT

DOW N

HELP MENU

456
123

0.E

C-16

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C.2.7 Diagnostic Tests

These tests verify the integrity of the detector electronics and functions.

DIAG NOSTIC TESTS

CE LL: INT NO ISE TE S T:

C • User Interface

RDY

DAC RAMP: SCOPE TEST: RDY

POW ER CPU

PP

RDY

P

Help M essag e

Figure C-15. Diagnostic Tests Screen

Screen Field Description
CELL

NOISE TEST

DAC RAMP

Specifies whether the cell to be tested is internal (INT) or external
(EXT).

Selects one of the following test modes:
RDY—The system is idle and ready to begin a test.
CD—Selects the conductivity cell for testing.
Selects the DAC test mode. The test linear ramps the output of the

selected DA on the SP or SCR card from 0 to full-scale and can be
plotted from the recorder output or from PeakNet. The ramp test
modes are:

RDY—The system is idle and ready to begin a test.
CDO—Tests the CD Offset DAC (eight iterations, one for each gain;

the eighth iteration is flat on top). Disconnect the conductivity cell
before running this test.

PSRS

LAN LEAK

DS3

CELL DRIVE

*
*>

SCOPE TEST

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REC—Tests the Recorder Output DAC.
Generates test waveforms that can be monitored on test points on the

SCR and SP cards, using an oscilloscope or chart recorder. The test
modes are:

RDY—The system is idle and ready to begin a test.

C-17

CD25 Conductivity Detector

Screen Field Description

CDF—Tests the CD Offset DAC output (TP9 on the SP card) and the
CD fine filter circuit (TP19 on the SP card). TP9 outputs a square
wave with a frequency of 200 ms and an amplitude from 0 to -0.1 V.
TP19 outputs a sine wave with a frequency of 200 ms. The peak-to­peak amplitude is 4.40 V.

CDT—Tests the CD Temperature Compensation DAC (TP26 on the
SP card). The output is a square wave in which the bottom and top
amplitudes increase and decrease from 11 V to 12 V. Before running
this test, connect the DS3 and set the temperature to 45 °C, or connect
a dummy thermistor value of 42 kΩ to pins 2 and 3 of the conductivity
cell connector.

SCR—Tests the SCR DAC for the DS3 set point temperature (TP13
on the SCR card) and SRS current set point (TP17 on the SCR card).
The output on each test point is a linear ramp that goes from 0 to 10 V
in 2.5 seconds. Disconnect the DS3 and SRS before running this test.

The following tests can be run from the

DIAGNOSTIC TESTS

screen. To

begin a test, select the asterisk (*) in the field beside the test name and

Enter

press
(pass) or

NOTE Running the following tests disturbs the

POWER
CPU

DX-LAN
SRS
DS3
CELL DRIVE

LEAK

. When the test is complete, the entry field displays either P

F

(fail).

equilibration of the detector as services cycle on and
off and the system runs through its test modes. After
testing, allow the system to equilibrate before
resuming operation.

Checks the +5, ±15, and +24 volt monitor on the Relay card.
Checks the CPU internal configuration and the Moduleware

checksum.
Checks the DX-LAN hardware configuration and loop-back.
Varies the SRS power supply and checks the flags.
Varies the DS3 temperature set point and checks the flags.
Switches in a resistor in place of the cell to provide a calibrated

signal to read.
Checks the detector's leak sensor for a correct, open circuit, or

short circuit condition.

C-18

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C.2.8 Leak Sensor Calibration and Status

This screen reports the status of leak sensor parameters.

LEAK SENSOR CALIBRATION AND STATUS

C • User Interface

MEASURED VALUE:

CURRENT CONDITION:

CALIBRATION VALUE:

LOW LEAK THRE SHOLD :

Help M essage

Figure C-16. Leak Sensor Calibration and Status Screen

Screen Field Description
MEASURED

VALUE
CURRENT

CONDITION

Reports the measured voltage from the leak sensor.

Reports the current (error) condition of the leak sensor: WET,
DRY, or ERR. Error indicates an open or short circuit. To
calibrate a leak sensor, select
calibration, the field will revert to DRY, unless an error
condition exists.

CALIBRATION
VALUE

LOW LEAK
THRESHOLD

Reports the value saved when the leak sensor was last calibrated.

Reports the threshold value below which a leak is indicated.
This is based on the calibration value.

2.48

DRY

2.50

2.70

CAL

and press

Enter

. After

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C-19

CD25 Conductivity Detector

C.2.9 Signal Statistics

This screen enab les y ou to monit or t he sel ected input to the A/D ci rcuit ry.
When the screen is first displayed, the
equal to the
reported in A/D volts and are updated dynamically.

CELL: NORM

INPUT:

Help Message

Screen Field Description

INPUT

SIGNAL STATISTICS

C FINE

MAX:

MIN:

DURATION:

Figure C-17. Signal Statistics Screen

value, and

n.nnn volts
n.nnn volts
n.nnn volts

nnn.nn Minutes

DURATION

MAX

and

MIN

status values are

reads 0. Status values are

CELL

INPUT

MAX
MIN
DURATION

Selects the cell test mode:
NORM—Uses input data from the cell.
FIXED—Uses a fixed dummy cell for input.
The measured data from the A/D circuit:
C FINE—Conductivity cell fine input
C COARSE—Conductivity cell coarse input
C THER—Conductivity cell thermistor input
LEAK—Leak detector input
DRIVE—Cell drive circuit input
The maximum input data value during the duration of the test.
The minimum input data value during the duration of the test.
The duration (in minutes) of the test. The test starts when you enter

this screen and terminates when you exit.

C-20

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C.2.10 Calibrate Conductivity Cell

This scree n allows you t o calibrate the conducti vity cell with 1 mM KCl.
See Section 5.4 for detailed instructions.

CALIBRATE CONDUCTIVITY CELL

MEASURED CONDUCTIVITY:

CELL CALIBRATION CONSTANT:

PUMP 1 mM KCl THROUGH CELL AT 1 mL/MIN.

SELECT 'C AL' AND PRESS ENTER RDY

WARNING : THIS W ILL ERASE THE PRIO R

CELL CALIBRATIO N AND STORE A NEW VALUE

Help M essage

Figure C-18. Calibrate Conductivity Cell Screen

Screen Field Description

146.54 u S

C • User Interface

160.0

MEASURED
CONDUCTIVITY

Calibration

Reports the measured conductivity from the conductivity cell.

CAL

Select
the value displayed in the conductivity field. The calibration
assumes that uncontaminated 1 mM KCl is flowing through the
cell at normal backpressure. The new value replaces the
previous calibration value.

and press

Enter

to calibrate the conductivity cell to

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C-21

CD25 Conductivity Detector

C-22

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D • TTL and Relay Control

The strip of eight 2-pin connectors on the CD25 electronics chassis provides two
relay outputs, two TTL outputs, and four TTL inputs (see Figure D-1).



Connect the outputs to the TTL or relay inputs of a Dionex or non-Dionex
device to control functions in the connected device. The devices must be
compatible with the CD25’s TTL and relay signals.



Connect the inputs to a Dionex or non-Dionex device to control four detector
functions.

Connection instructions are in Section D.1.

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Figure D-1. TTL Connector Strip

(CD25 Front View without Upper Door)

D-1

CD25 Conductivity Detector

D.1 TTL and Relay Connections

The TTL/relay connector strip is located on the electronic chassis behind the
upper door (see FigureD-1). Each 2-pin connector includes a signal pin and a
ground pin.

1. Twisted pairs of wires (P/N 043598) and two-pin connector plugs
(P/N 921019) are provided in the CD25 Ship Kit. Attach a two-pin plug to
each end of the twi st ed pai r of wires to be connected. The signal wir e goes on
top and the ground wire goes on the bottom of each plug.

2. Connect these plug s to the TTL or relay connec tors on t he CD25 and th e other
module(s) as needed for your application. Check the polarity of each
connection. Connect signal wires to signal (+) pins and ground wires to
ground (-) pins. If necessary, remove wires from the two-pin plugs and
reinsert them in the correct positions.

3. Route the wires from the CD25 elec tr onics ch assis through the upper chase to
the rear pan el.

NOTE Relay outputs 1 and 2 can be programmed to switch

any low-voltage control (see Section D.2). Switched
current must be less than 200 mA and 42 V peak

.

D-2

The relay outputs, TTL inputs, and TTL outputs all use a
connector of the same style. Do not inadvertently connect
relay loads that include power supplies to the TTL inputs or
TTL outputs. Relay loads in excess of 200 mA or with included
power supplies over 42 V may damage the rela y driv ers on the
CPU module.

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