Dionex GP50 User manual

GP50 GRADIENT PUMP
OPERATOR'S MANUAL
© 2001 Dionex Corporation
Document No. 031377
Revision 03
July 2001

©2001 by Dionex Corporation
All rights reserved worldwide.
Printed in the United States of America.
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
DX-LAN™ is a trademark, and PeakNet®, Self-Regenerating Suppressor®, and
SRS® are registered trademarks of Dionex Corporation
Tefzel® is a registered trademark of E.I. duPont de Nemours & Co.
PRINTING HISTORY
Revision 01, May 1998
Revision 02, October 2000
Revision 03, July 2001

Doc. 031377-03 7/01 i
Contents
1 • Introduction
1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
1.2 About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
1.2.1 Safety Messages and Notes . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
1.2.2 Safety Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
2 • Description
2.1 Front Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
2.1.1 Control Panel Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
2.1.2 Display Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7
2.2 Electronics Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
2.3 Mechanical Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11
2.4 Mechanical Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12
2.4.1 Pump Eluent Manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13
2.4.2 Pump Heads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14
2.4.3 Pump Mixers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14
2.4.4 Pump Priming Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15
2.4.5 Pressure Transducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15
2.5 Vacuum Degas Pump Assembly (Optional) . . . . . . . . . . . . . . . . . . . .2-16
2.6 Piston Seal Wash (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16
2.7 Eluent Reservoirs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-17

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2.8 Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.9 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.9.1 Operating and Control Modes . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.9.2 Local and Remote Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
2.9.3 Method Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
2.9.4 Eluent Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
3 • Operation and Maintenance
3.1 Getting Ready to Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1.1 Degas Eluents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1.2 Filter Eluents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.1.3 Pressurize Eluent Reservoirs . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.1.4 Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.1.5 Selecting the Pressure Limits . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.1.6 Selecting the Operating and Control Modes . . . . . . . . . . . . . . 3-5
3.2 Running Under Direct Control (Local Mode) . . . . . . . . . . . . . . . . . . . 3-6
3.3 Running Under Method Control (Local Mode) . . . . . . . . . . . . . . . . . . 3-7
3.3.1 Creating a New Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
3.3.2 Running a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
3.3.3 Editing a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
3.3.4 Deleting a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
3.3.5 Changing the Running Method . . . . . . . . . . . . . . . . . . . . . . . 3-12
3.3.6 Controlling the Method Clock . . . . . . . . . . . . . . . . . . . . . . . . 3-12

Contents
Doc. 031377-03 7/01 iii
3.4 Example Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13
3.4.1 Isocratic Method Example . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13
3.4.2 Linear Gradient Method Example . . . . . . . . . . . . . . . . . . . . .3-14
3.4.3 Curved Gradient Method Example . . . . . . . . . . . . . . . . . . . . .3-19
3.4.4 Editing a Running Method Example . . . . . . . . . . . . . . . . . . .3-23
3.5 Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-25
3.5.1 Daily Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-25
3.5.2 Periodic Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-27
3.6 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-27
4 • Troubleshooting
4.1 Left-Right Pump Head Pressure Fluctuations . . . . . . . . . . . . . . . . . . . .4-1
4.2 Pump Will Not Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
4.3 Pump Stops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
4.4 Liquid Leaks/Leak Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7
4.5 Noisy Pump Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
4.6 Vacuum Degas Pump Does Not Run . . . . . . . . . . . . . . . . . . . . . . . . . .4-9
4.7 Vacuum Degas Pump Calibration Fails . . . . . . . . . . . . . . . . . . . . . . .4-10
4.8 Vacuum Degas Pump Low Vacuum . . . . . . . . . . . . . . . . . . . . . . . . . .4-11
4.9 Relays or TTLs Inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11
4.10 Poor Chromatographic Reproducibility . . . . . . . . . . . . . . . . . . . . . . .4-12

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iv Doc. 031377-03 7/01
5•Service
5.1 Cleaning and Replacing the Check Valves . . . . . . . . . . . . . . . . . . . . . . 5-1
5.2 Piston Seal Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.3 Pump Piston Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
5.4 Pressure Transducer Waste Valve O-Ring Replacement . . . . . . . . . . 5-10
5.5 Proportioning Valve Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
5.6 Changing Main Power Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
A • Specifications
A.1 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
A.2 Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
A.3 Physical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
A.4 Display and Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
A.5 Hydraulics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2
A.6 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-3
A.7 Vacuum Degas Pump Assembly (Optional) . . . . . . . . . . . . . . . . . . . . .A-3
B • Installation
B.1 Facility Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1
B.2 Installation Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-2
B.2.1 Power Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-2
B.2.2 Electronics Chassis Connections . . . . . . . . . . . . . . . . . . . . . . .B-4
B.2.3 DX-LAN Interface: 10BASE-T Connections (Optional). . . . .B-6

Contents
Doc. 031377-03 7/01 v
B.2.4 DX-LAN Interface: BNC Connections (Optional) . . . . . . . . . B-9
B.2.5 Waste Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-13
B.2.6 Eluent Inlet Line Connections. . . . . . . . . . . . . . . . . . . . . . . . B-14
B.2.7 Eluent Outlet Line Connections . . . . . . . . . . . . . . . . . . . . . . B-14
B.2.8 Piston Seal Wash Connections (Optional) . . . . . . . . . . . . . . B-15
B.2.9 Priming the Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-17
B.3 Automatic SRS Power Control (Optional) . . . . . . . . . . . . . . . . . . . . B-20
C • Display Screens
C.1 Operational Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2
C.1.1 Menu of Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2
C.1.2 Main Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3
C.1.3 Detail Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5
C.1.4 Method Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-6
C.1.5 Method Extension Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-8
C.1.6 Degas Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-9
C.1.7 Module Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-11
C.1.8 Pump Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-12
C.1.9 Time Function In. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-13
C.2 Diagnostic Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-14
C.2.1 Diagnostic Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-14
C.2.2 Power-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-15
C.2.3 Elapsed Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-16
C.2.4 DSP Status. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-17

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vi Doc. 031377-03 7/01
C.2.5 DX-LAN Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-18
C.2.6 Keyboard Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-20
C.2.7 Diagnostic Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-21
C.2.8 Pressure Statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-23
C.2.9 DSP Code Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-24
C.3 Calibration Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-25
C.3.1 Calibration Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-25
C.3.2 Calibration Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-26
C.3.3 Leak Sensor Calibration and Status . . . . . . . . . . . . . . . . . . . .C-27
C.3.4 Degas Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-28
C.3.5 Flow Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-29
C.3.6 Pressure Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-30
C.3.7 Degas Pump Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-34
D • TTL and Relay Control
D.1 TTL and Relay Output Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-2
D.2 TTL Input Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-3
D.2.1 TTL Input Signal Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-3
D.3 TTL and Relay Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-5
D.3.1 Example Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-6

Doc. 031377-03 7/01 1-1
1 • Introduction
1.1 Overview
The GP50 Gradient Pump is an integral part of a Dionex chromatography system.
It is a microprocessor-based, dual-piston, variable-speed, gradient delivery system
designed to blend and pump mixtures of up to four different eluents at precisely
controlled flow rates. The pump can deliver the selected eluent composition
isocratically, or as a multistep linear or curved gradient. A Digital Signal
Processor (DSP) provides high speed control of pump flow and pressure.
The pump can operate as a stand-alone product or with other Dionex modules as
part of a complete chromatography system. It can also be used with non-Dionex
modules that meet interface requirements for software, TTL, or relay control.
The GP50 can be controlled locally, using the front panel keypad and display, or
from a remote host computer with a Dionex DX-LAN™ interface installed and
PeakNet®software installed on the host computer. Limited remote control is also
available from any device capable of providing compatible TTL signals to control
the pump.
The pump's two basic modes of control, Direct control and Methodcontrol, enable
it to operate with or without reference to time-based events.
The GP50 is available in four versions. An optional vacuum degas pump is
available for all versions:
GP50 Gradient Pump Version With Degas Pump Without Degas Pump
Standard bore with PEEK
components P/N 054426 P/N 054427
Standard bore with stainless steel
components P/N 054419 P/N 054420
Microbore with PEEK components P/N 054045 P/N 054429
Microbore with stainless steel
components P/N 054425 P/N 054424

GP50 Gradient Pump
1-2 Doc. 031377-03 7/01
1.2 About This Manual
Chapter 1
Introduction Gives an overview of the GP50 Gradient Pump, and
explains conventions used in this manual, including
safety-related information.
Chapter 2
Description Describes the GP50 front panel controls, electronic and
mechanical components, and operating modes.
Chapter 3
Operation and
Maintenance
Provides an overview of GP50 operation, including how to
create, edit, and run methods from the GP50 front panel.
Lists routine preventive maintenance procedures.
Chapter 4
Troubleshooting Lists problems and presents step-by-step procedures for
how to isolate and eliminate them.
Chapter 5
Service Provides step-by-step instructions for routine service and
parts replacement procedures.
Appendix A
Specifications Lists the GP50 specifications and installation site
requirements.
Appendix B
Installation Describes how to install the GP50.
Appendix C
Display Screens Illustrates and describes all of the screens that can be
displayed on the GP50 front panel.
Appendix D
TTL and Relay
Control
Describes relay and TTL input and output functions and
provides installation instructions.

1 • Introduction
Doc. 031377-03 7/01 1-3
1.2.1 Safety Messages and Notes
This manual contains warnings and precautionary statements that, when
properly followed, can prevent personal injury and/or damage to the
GP50. Safety messages appear in bold type and are accompanied by
icons, as shown below.
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.
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.

GP50 Gradient Pump
1-4 Doc. 031377-03 7/01
1.2.2 Safety Labels
The TUV GS, C, US Mark safety label and the CE Mark label on the
GP50 indicate that the GP50 is in compliance with the following
standards: EN 61010-1:1993 (safety), CAN/CSA-C22.2 No. 1010.1-92
(safety), UL 3101-1/10.93 (safety), EN 50082-1:1992 (susceptibility),
and EN 55011:1991 (emissions).
The symbols below appear on the GP50, or on GP50 labels.
Alternating current
Protective conductor terminal
Power supply is on
Power supply is off

Doc. 031377-03 7/01 2-1
2 • Description
The GP50 Gradient Pump consists of two units (see Figure 2-1). The upper unit
houses the electronics components and the lower unit houses the pump heads and
other mechanical pump assemblies.
Figure 2-1. GP50 Enclosure
Pump
Heads

GP50 Gradient Pump
2-2 Doc. 031377-03 7/01
2.1 Front Control Panel
The control panel on the upper door of the pump enclosure contains a liquid
crystal display (LCD), a membrane keypad, and the actuator for the main power
switch (see Figure 2-2). The door opens to provide access to the electronics
chassis (see Section 2.2).
NOTE If no keypad buttons are pressed within a two-hour
period, the front panel backlight will automatically turn
off. To restore the backlight, press any button.
Screen Contrast
Information is displayed on the LCD, also called the screen. To adjust the screen
contrast, use the knurled knob in the recess below the keypad (see Figure 2-2).
Tilt Panel
To maximize visibility, the front control panel can be tilted to four different
positions. To tilt the panel, support the door at the left side (to prevent it from
opening) and lift firmly on the tab in the middle of the recess below the keypad
(see Figure 2-2). Push on the tab to return the panel to its vertical position.
Power Switches
The main power switch is on the bulkhead behind the upper door (see Figure 2-1).
An actuator for the main power switch is on the outside of the front door, at the
lower left corner (see Figure 2-2).
The actuator functions only when the door is fully closed. When the door is open,
press the main power switch on the bulkhead to turn the module off and on.
To prevent damage to the pump circuitry and components,
always wait at least 15 seconds after powering down before
turning on the power again.

2•Description
Doc. 031377-03 7/01 2-3
2.1.1 Control Panel Keypad
Use the keypad to directly control pump operation, as well as to create
and modify programmed series of timed events, called methods. In
summary:
_Press Menu to display a list of available screens.
_To go from a menu to a screen, press the numeric button that
corresponds to the screen’s number on the menu, or move the cursor
to the desired screen name and press Enter.
_Only fields shown in reverse video on a screen can be edited. Other
fields display information only.
_To edit a value in a reverse video field, use the four directional arrow
buttons to move the cursor to the field. Use the numeric buttons to
Figure 2-2. GP50 Display and Keypad Layout
GP50 Gradient Pump
Hold/Run
1
0
23
456
789
Enter
Off/On
Prime Reset
Insert Select
Delete Select Help Menu
Tab
(for opening
the door)
Tab
(for tilting
the panel)
Knob
(for adjusting
the contrast)
Main Power
Switch Actuator
Help Message
PSI
LOAD
METHOD
100.0 %A
0.0 %B
0.0 %C
0.0 %D
COLUMN A
2000
mL/MIN
2.00
LOCAL 2
MIN
10.27

GP50 Gradient Pump
2-4 Doc. 031377-03 7/01
enter variable values, or use the Select ∆and Select ∇buttons to
choose from among predetermined options.
_To confirm the selected value, press Enter or an arrow button. In
some screens or screen fields, pressing Enter is required.
NOTE A high-pitched beep sounds when you press a
button. When an error occurs, this beep is lower in
frequency. The beeps can be disabled from the
MODULE SET-UP screen (see Section C.1.7).
Keypad
Buttons Function
Turns the pump motor off and on.
In Direct control (see Section 2.9), turning on the motor causes it to
pump isocratically using the displayed eluent percentages and flow rate.
In Method control (see Section 2.9.3), turning on the motor causes it to
pump at the eluent percentages and flow rate for the elapsed time of the
selected method, or at the initial conditions (when the method clock is at
INIT).
This button is used when priming the pump heads. Prime causes the
pump to run at maximum volume (2.5 mL/min, microbore; 10.0 mL/min,
standard bore). If the pump motor is off when Prime is pressed, the
pump automatically turns on. To exit priming and return to the normal
flow rate, press Prime again or press Off/On to turn off the pump motor.
See Section B.2.8 for detailed priming instructions.
Inserts a new step into a method. This button functions only when the
cursor is in a TIME field on the METHOD or METHOD extension screen.
1. Move the cursor to the TIME field and press Insert. The new step is
added below the cursor position. Parameter values in the new step
are blank.
2. Fill in the time value and press Enter or a cursor arrow button.
Note: If you move the cursor out of the TIME field before entering a
time value, the inserted step is not saved because it is incomplete.
3. Insert steps in any order. When you press Enter, they will be
automatically reorganized in the correct chronological order.
Table 2-1. GP50 Front Panel Buttons

2•Description
Doc. 031377-03 7/01 2-5
Removes the value from the current entry field. To restore the previous
value, move the cursor from the field before entering a new value.
Pressing Delete when the cursor is in a step entry field on the METHOD
screen “blanks” the step parameter value. Moving the cursor 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 Delete again. Or, to restore the original time and step
parameters, press any button except Delete.
Turns the method clock off (Hold) and on (Run). This button functions
only when the pump is under Method control (see Section 2.9.3).
When the method clock is in Hold, pressing 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.
When the method clock is in Run, pressing Hold/Run stops the clock;
this “holds” the method and freezes the current conditions.
Changes the method clock time to INIT, causing the initial conditions
specified by the method to occur. This button functions only when the
GP50 is under Method control (see Section 2.9.3).
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
numeric values, pressing Select ∆increases the value by one unit;
pressing Select ∇decreases the value by one unit. Holding down a
Select button increases (or decreases) the value continuously. Press
Enter or a cursor arrow button to confirm the selected value.
Keypad
Buttons Function
Table 2-1. GP50 Front Panel Buttons (Continued)

GP50 Gradient Pump
2-6 Doc. 031377-03 7/01
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 TO field, the METHOD RUN field, any calibration
command, the DIAGNOSTIC TESTS screen, and all menu screens.
Displays a help screen with information pertaining to the current entry
field.
Displays one of three menus, depending on the current screen:
_From an operational screen, pressing Menu displays the MENU of
SCREENS.
_From a diagnostic screen, pressing Menu displays the
DIAGNOSTIC MENU.
_From a calibration screen, pressing Menu displays the
CALIBRATION MENU.
Enters numeric values into the current entry field. The numeric buttons
are 0 through 9 and the decimal.
From a menu screen, pressing a numeric button opens the corresponding
screen.
Saves and/or executes changes made in entry fields. If a menu screen is
displayed, pressing Enter opens the highlighed screen.
Keypad
Buttons Function
Table 2-1. GP50 Front Panel Buttons (Continued)

2•Description
Doc. 031377-03 7/01 2-7
2.1.2 Display Screens
When the pump has successfully powered-up and passed all diagnostic
tests, the POWER-UP screen (see Figure 2-3) displays briefly, followed by
the MAIN screen (see Figure 2-4). If one of the diagnostic tests fails at
power-up, the DIAGNOSTIC TEST screen displays instead of the MAIN
screen. See Section C.2.7 if this occurs.
NOTE The POWER-UP screen can be viewed at any time by
selecting the screen from the DIAGNOSTIC MENU
(see Section C.2.1).
The MAIN screen displays status information in enlarged characters to
allow viewing from a distance. Use the MAIN screen to select operating
parameters, such as the flow rate and the percentages of eluents to run.
To access other GP50 screens, press the Menu button to display the MENU
of SCREENS (see Figure 2-5).
Figure 2-3. Power-Up Screen
Figure 2-4. Main Screen
Help Message
GP50 GRADIENT PUMP
PUMP HEAD VOLUME 100 uL
MODULEWARE REV n.nn
BIOS REV n.nn
Help Message
PSI
LOAD
METHOD
100.0 %A
0.0 %B
0.0 %C
0.0 %D
COLUMN A
2000
mL/MIN
2.00
LOCAL 2
MIN
10.27

GP50 Gradient Pump
2-8 Doc. 031377-03 7/01
There are two ways to select a screen from a menu:
_Press the numeric button on the front panel keypad that corresponds
to the screen number on the menu. For example, press 3 to display the
METHOD screen.
_Move the cursor to the field containing the screen number and press
Enter.
See Appendix C for a description of each screen.
2.2 Electronics Chassis
The electronics chassis is located behind the upper door of the pump enclosure.
The chassis includes several electronics cards (printed circuit boards) that are used
to control the pump. Connectors on the cards also allow communication between
the pump and other Dionex chromatography modules. Figure 2-6 shows the
electronics components with the upper door open. To open the door, pull on the
tab located to the right of the main power actuator (see Figure 2-2).
Figure 2-5. Menu of Screens
Do not remove any of the electronics cards from the pump.
There are no user-serviceable components on the cards. If
servicing is required, it must be performed by qualified
personnel and appropriate electrostatic discharge (ESD)
handling procedures must be followed.
Ne retirez aucune des cartes électroniques de la pompe. Aucun
des composants sur les cartes ne peut être réparé par
l'utilisateur. Toute réparation doit être effectuée par un
personnel qualifié utilisant des procédures correctes de
décharge électrostatique.
Help Message
MAIN SCREEN
DETAIL SCREEN
METHOD
DEGAS OPTIONS
MODULE SET-UP
PUMP OPTIONS
TIME FUNCTION IN
DIAGNOSTIC MENU
1
2
3
4
5
6
7
8
MENU of SCREENS