IBM 7220 - page 130

E-6

Appendix E, ALPHABETICAL LISTING OF COMMANDS

<X output value1><delim><Magnitude value1><term>

<X output value2><delim><Magnitude value2><term>

<X output value3><delim><Magnitude value3><term>

<X output value4><delim><Magnitude value4><term>

<X output value5><delim><Magnitude value5><term>

etc, where <delim> and <term> are the delimiter and terminator characters

respectively.

The computer program’s subroutine which reads the responses to the DCT command

needs to run a FOR...NEXT loop of length equal to the value set by the LEN (curve

length) command, and must be able to separate the responses on each line for storage

or processing.

Note that when using this command with the GPIB interface the serial poll must be

used. After sending the DCT command, perform repeated serial polls until bit 7 is set,

indicating that the instrument has an output waiting to be read. Then perform

repeated reads in a loop, waiting each time until bit 7 is set indicating that a new

value is available. The loop should continue until bit 1 is set, indicating that the

transfer is completed.

DD [n] Define delimiter control

The value of n, which can be set to 13 or 32 to 125, determines the ASCII value of

the character sent by the lock-in amplifier to separate two numeric values in a two-

value response, such as that generated by the MP (magnitude and phase) command.

ENBW[.] Equivalent noise bandwidth

In fixed point mode, reports the equivalent noise bandwidth of the output low-pass

filters at the current time constant setting in microhertz.

In floating point mode, reports the equivalent noise bandwidth of the output low-pass

filters at the current time constant setting in hertz.

This command is not available when the reference frequency exceeds 60 kHz.

EVENT [n] Event marker control

During a curve acquisition, if bit 13 in the CBD command has been asserted, the

lock-in amplifier stores the value of the Event variable at each sample point. This can

be used as a marker indicating the point at which an experimental parameter was

changed. The EVENT command is used to set this variable to any value between 0

and 32767.

Contents

Main FCC Notice Declaration of Conformity Table of Contents Table of Contents Chapter One, Introduction Chapter Two, Installation & Initial Checks Chapter Three, Technical Description Chapter Four, Front and Rear Panels Chapter Five, Front Panel Operation Chapter Six, Computer Operation Appendix A, Specifications Page Page Introduction Chapter 1 1.1 How to Use This Manual Chapter 1, INTRODUCTION 1.2 What is a Lock-in Amplifier? Chapter 1, INTRODUCTION 1.3 Key Specifications and Benefits Page Installation & Initial Checks Chapter 2 2.1 Installation 2.1.01 Introduction 2.1.02 Rack Mounting Page 2.2 Initial Checks 2.2.01 Introduction 2.2.02 Procedure Page Technical Description Chapter 3 3.1 Introduction 3.2 Principles of Operation 3.2.01 Block Diagram 3.2.02 Signal-Channel Inputs 3.2.03 Line Frequency Rejection Filter 3.2.04 AC Gain 3.2.05 Anti-Aliasing Filter 3.2.06 Main Analog to Digital Converter 3.2.07 Reference Channel DSP 3.2.08 Internal Oscillator 3.2.09 Demodulator DSP 3.2.10 Output Processor 3.2.11 Main Microprocessor 3.3 Accuracy 3.3.01 Absolute Accuracy Specifications 3.3.02 Relative Accuracy 3.4 Full-Scale Sensitivity and AC Gain Control 3.5 Dynamic Reserve 3.6 System Updates and Reference Frequency Changes 3.7 Reference Phase and Phase Shifter 3.8 Output Channel Filters 3.8.01 Slope 3.8.02 Time Constants and Synchronization 3.8.03 Output Offset and Expand 3.9 Use of Magnitude and Signal Phase Outputs Page 3.10 Noise Measurements 3.11 Power-up Defaults 3.12 Auto Functions 3.12.01 Introduction 3.12.02 Auto-Sensitivity 3.12.03 Auto-Phase 3.12.04 Auto-Offset 3.12.05 Auto-Measure 3.12.06 Default Setting Front and Rear Panels Chapter 4 4.1 Front Panel 4.1.01 A and B/I Signal Input Connectors 4.1.02 OSC OUT Connector 4.1.03 REF IN Connector 4.1.04 Left-hand LCD Display Panel Page 4.1.05 MENU Key 4.1.06 90 Key 4.1.07 SET Key 4.1.08 Right-hand LCD Display Panel 4.2 Rear Panel 4.2.01 Line Power Switch 4.2.02 Line Power Input Assembly Page Page Front Panel Operation Chapter 5 5.1 Introduction 5.2 Setup Menu Mode 5.2.01 Input Setup Menu Page 5.2.02 Reference Setup Menu ON OFF 5.2.03 Output Setup Menu Expand Page PHASE1 PHASE2 NOISE RATIO 5.2.04 Control Options Menu Linefilt AC Gain Page 5.2.05 Miscellaneous Options Menu 5.2.06 RS232 Setup 1 Menu 5.2.07 RS232 Setup 2 Menu 5.2.08 RS232 Setup 3 Menu Address Information only 5.2.09 GPIB Setup 1 Menu 5.2.10 GPIB Setup 2 Menu SRQ Mask Test echo 5.2.11 Digital Outputs Setup Menu Decimal 5.2.12 Control Setup Menu Default Setting Sample rate 5.3 Auto Functions Menu AUTO SEN AUTO PHASE AUTO OFFSET AUTO MEASURE 5.4 Main Display Mode - Left-hand LCD Page Page Page Page Page 5.5 Main Display Mode - Right-hand LCD Page Page Page Page Page Page Page Page 5.6 Typical Lock-in Amplifier Experiment Page Computer Operation Chapter 6 6.1 Introduction 6.2 Capabilities 6.2.01 General 6.3 RS232 and GPIB Operation 6.3.01 Introduction 6.3.02 RS232 Interface - General Features 6.3.03 Choice of Baud Rate 6.3.04 Choice of Number of Data Bits 6.3.05 Choice of Parity Check Option 6.3.06 Auxiliary RS232 Interface 6.3.07 GPIB Interface - General Features 6.3.08 Handshaking and Echoes 6.3.09 Terminators 6.3.10 Command Format 6.3.11 Delimiters 6.3.12 Compound Commands 6.3.13 Status Byte, Prompts and Overload Byte Page 6.3.14 Service Requests 6.4 Command Descriptions 6.4.01 Signal Channel Page Page 6.4.02 Reference Channel 6.4.03 Signal Channel Output Filters 6.4.04 Signal Channel Output Amplifiers 6.4.05 Instrument Outputs Page Page 6.4.06 Internal Oscillator 6.4.07 Auxiliary Outputs 6.4.08 Auxiliary Inputs Page 6.4.09 Output Data Curve Buffer Page Page Page 6.4.10 Computer Interfaces (RS232 and GPIB) Page 6.4.11 Instrument Identification 6.4.12 Front Panel 6.4.13 Default Setting 6.5 Programming Examples 6.5.01 Introduction 6.5.02 Basic Signal Recovery 6.5.03 Frequency Response Measurement 6.5.04 X and Y Output Curve Storage Measurement 6.5.05 Transient Recorder 6.5.06 Frequency Response Measurement using Curve Storage and Frequency Sweep Page Specifications Appendix A Measurement Modes Displays Signal Channel Reference Channel Demodulator and Output Processing Oscillator Auxiliary Inputs Outputs Data Storage Interfaces Power Requirements General Pinouts Appendix B B.1 RS232 Connector Pinout B.2 Preamplifier Power Connector Pinout Appendix B, PINOUTS B.3 Digital Output Port Connector Demonstration Programs Appendix C C.1 Simple Terminal Emulator C.2 RS232 Control Program with Handshakes Page C.3 GPIB User Interface Program Page Cable Diagrams Appendix D D.1 RS232 Cable Diagrams Page Alphabetical Listing of Commands Appendix E Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Default Settings Appendix F Default Setting Function Appendix F, DEFAULT SETTINGS Index Index Index-1 Index-2 Index-3 Index-4 Index-5 Page WARRANTY SHOULD YOUR EQUIPMENT REQUIRE SERVICE