Ametek 7230 Instruction Manual
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Ametek 7230 Instruction Manual

Ametek 7230 Instruction Manual

Dsp lock-in amplifier
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Model 7230
DSP Lock-in Amplifier
Instruction Manual
198004-A-MNL-C
Copyright © 2017 AMETEK ADVANCED MEASUREMENT TECHNOLOGY, INC

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Summary of Contents for Ametek 7230

  • Page 1 Model 7230 DSP Lock-in Amplifier Instruction Manual 198004-A-MNL-C Copyright © 2017 AMETEK ADVANCED MEASUREMENT TECHNOLOGY, INC...
  • Page 2 Firmware Version The instructions in this manual apply to operation of a Model 7230 DSP Lock-in Amplifier that is fitted with Version 2.20 or later operating firmware. Users of instruments that are fitted with earlier firmware versions can update them to the current version free of charge by downloading an Update Pack from our website at www.signalrecovery.com The pack includes full instructions for use.

  • Page 3: Table Of Contents

    Table of Contents Table of Contents General Safety Precautions ......................vii Chapter One, Introduction 1.1 How to Use This Manual..........................1-1 1.2 What is a Lock-in Amplifier? ......................... 1-10 1.3 Key Specifications and Benefits ........................1-16 Chapter Two, Installation and Initial Checks 2.1 Installation ................................
  • Page 4 TABLE OF CONTENTS 3.3.16 Fast Curve Buffer ...........................3-87 3.3.17 Main Output Processor - General ......................3-91 3.3.18 Main Output Processor - Output Offset and Expand ................3-93 3.3.19 Main Output Processor - Vector Magnitude and Phase .................3-94 3.3.20 Main Output Processor - Noise Measurements ..................3-103 3.3.21 Main Output Processor - Standard Curve Buffer .................3-112 3.3.22 Analog Outputs (DACs) ........................3-114 3.3.23 Auxiliary Analog Inputs (ADCs) ......................3-119...
  • Page 5 TABLE OF CONTENTS 5.3.07 Main Controls: Reference 2 ........................ 5-142 5.3.08 Main Controls: Output 2 ........................5-153 5.3.09 Main Controls: Output Filters ......................5-163 5.3.10 Main Controls: Demodulator Control ....................5-167 5.3.11 Main Controls: Status Indicators ......................5-176 5.3.12 Oscillator: Overview ........................... 5-183 5.3.13 Oscillator: Sweep Control ........................
  • Page 6 TABLE OF CONTENTS 6.5.04 Sockets ..............................6-52 6.5.05 Terminator, Status Byte, and Overload Byte ..................6-54 6.5.06 Delimiters ...............................6-61 6.7 Command Descriptions ...........................6-70 6.7.01 Signal Channel ............................6-71 6.7.02 Reference Channel ..........................6-93 6.7.03 Signal Channel Output Filters ......................6-112 6.7.04 Signal Channel Output Amplifiers .......................6-125 6.7.05 Instrument Outputs ..........................6-132 6.7.06 Internal Oscillator ..........................6-157 6.7.07 Analog Outputs ............................6-187...

  • Page 7: General Safety Precautions

    TABLE OF CONTENTS GENERAL SAFETY PRECAUTIONS The equipment described in this manual has been designed in accordance with EN61010 "Safety requirements for electrical equipment for measurement, control and laboratory use", and has been supplied in a safe condition. To avoid injury to an operator or service technician the safety precautions given below, and throughout the manual, must be strictly adhered to, whenever the equipment is operated, serviced or repaired.
  • Page 8 Acknowledgment Operation of the Ethernet interface in the model 7230 relies on software code developed by the Swedish Institute of Computer Science, copyright 2001-2004, all rights reserved. In accordance with...
  • Page 9 89/336/EEC Electromagnetic Compatibility Directive, amended by 92/31/EEC & 93/68/EEC Product(s) Model 7230 DSP Lock-in Amplifier Basis on which conformity is being declared The product(s) identified above comply with the requirements of the EU directives by meeting the following standards: BS EN61326-1:2006 Electrical equipment for measurement control and laboratory use - EMC requirements –...

  • Page 11: Chapter One, Introduction

    Chapter 1.1 How to Use This Manual This manual gives detailed instructions for setting up and operating the SIGNAL RECOVERY Model 7230 DSP Lock-in Amplifier. It is split into the following chapters:- Chapter 1 - Introduction Provides an introduction to the manual, briefly describes the function of a lock-in amplifier and the types of measurements it may be used for, and lists the major specifications of the model 7230.

  • Page 12: What Is A Lock-In Amplifier

    DSP (digital signal processing) designs, further improving performance. The model 7230 DSP lock-in amplifier uses the latest DSP technology for signal detection, and a powerful processor for easy user operation. The low-noise analog...

  • Page 13: Key Specifications And Benefits

    Chapter 1, INTRODUCTION 1.3 Key Specifications and Benefits The SIGNAL RECOVERY Model 7230 represents a further significant advance in the application of DSP technology in the design of a lock-in amplifier. Key specifications include:  Frequency range: Standard unit 0.001 Hz to 120.000 kHz With 7230/99 option 0.001 Hz to 250.000 kHz...
  • Page 14 Chapter 1, INTRODUCTION...

  • Page 15: Installation

    The model 7230 does not use forced-air ventilation; however it should be located so that there is reasonable flow of air around it to aid cooling.

  • Page 16: Procedure

    PS0110 to the 7230’s rear panel POWER INPUT connector. 6) Turn on the model 7230. The front panel status light should be green. 7) Open a browser session on the computer. Since there is no connection to the internet you will not see the normal opening page, but an error message.
  • Page 17 Chapter 2, INSTALLATION AND INITIAL CHECKS Figure 2-3, Model 7230 Main Controls Panel 9) Click the Equations tab, to show the Equations panel, as shown below in figure Figure 2-4, Model 7230 Equations Panel 10) Click the Auto Default button. This will set all instrument controls to the factory...
  • Page 18 12) Save the address as a favorite, bookmark, or shortcut (figure 2-6) so that you can quickly reach the model 7230 again if repeating the test, as in figure 2-7 Figure 2-6, Saving the Model 7230’s IP address as a favorite...
  • Page 19 Chapter 2, INSTALLATION AND INITIAL CHECKS Figure 2-7, Accessing the favorite 13) This completes the initial checks. Even though the procedure leaves many functions untested, if the indicated results were obtained then the user can be reasonably sure that the unit incurred no hidden damage in shipment and is in good working order.
  • Page 20 Chapter 2, INSTALLATION AND INITIAL CHECKS...

  • Page 21: Introduction

    3.2.02 Single Reference / Dual Reference Conventionally, a lock-in amplifier makes measurements such as signal magnitude, phase, etc. on the applied signal at a single reference frequency. In the model 7230 this is referred to as the single reference mode.

  • Page 22: Internal / External Reference Mode

    The model 7230 allows this multiple to be set to any value between 2 (i.e. the second harmonic) and 127, as well as unity, which is the normal mode.

  • Page 23: Signal Channel Inputs

    Chapter 3, TECHNICAL DESCRIPTION Figure 3-1, Model 7230 - Block Diagram 3.3.02 Signal Channel Inputs The signal input amplifier can be set for either single-ended or differential voltage mode operation, or single-ended current mode operation. In voltage mode a choice of AC or DC coupling is available using an FET or bipolar input device.

  • Page 24: Line Frequency Rejection Filter

    Chapter 3, TECHNICAL DESCRIPTION B (I) inputs when operating in differential input mode. It is usually given in decibels. Hence a specification of > 100 dB implies that a common mode signal (i.e. a signal simultaneously applied to both A and B (I) inputs) of 1 V will give rise to less than 10 µV of signal out of the input amplifier.
  • Page 25 Chapter 3, TECHNICAL DESCRIPTION AC Gain (dB) INPUT LIMIT (zero to peak) 2.5 V 1.2 V 625 mV 312 mV 156 mV 78 mV 39 mV 19 mV 10 mV 5.0 mV 2.5 mV 1.2 mV 625 µV 312 µV 156 µV 78 µV Table 3-1, Input Limit vs.

  • Page 26: Anti-Aliasing Filter

    Applying this formula to the model 7230 at the maximum value of INPUT LIMIT (2.5 V) and the smallest available value of FULL-SCALE SENSITIVITY (10 nV), gives a maximum available dynamic reserve of about 165 dB. Figures of this...

  • Page 27: Main Analog-To-Digital Converter

    3.3.07 Reference Channel Inputs External reference signals are normally applied to the model 7230 via the front panel REF IN connector. Internally this can be switched to function as a general-purpose input, designed to accept virtually any periodic waveform with a 50:50 mark-space ratio and of suitable amplitude, or specifically set to accept TTL-logic level signals.

  • Page 28: Phase-Shifter

    Chapter 3, TECHNICAL DESCRIPTION external references. External Reference Mode In external reference mode the reference is taken from the front panel external reference input, except in dual external reference mode, when the second reference is applied to the rear panel TRIG IN input. Internal Reference Mode With internal reference operation the reference circuit is free-running at the selected reference frequency and is not dependent on a phase-locked loop (PLL), as is the...

  • Page 29: Internal Oscillator - General

    The model 7230, in common with many other lock-in amplifiers, incorporates an internal oscillator, which may be used to drive the experiment. However, unlike older instruments, the oscillator in the model 7230 is digitally synthesized with the result that the output frequency is extremely accurate and stable. The oscillator operates over the same frequency range as the lock-in amplifier, that is 1 mHz to 120.0 or 250.0 kHz.

  • Page 30: Internal Oscillator - Voltage Control

    12 dB per octave. These terms have become part of the accepted terminology relating to lock-in amplifier output filters and are used in the model 7230 to apply to the envelope of the frequency response function of the digital finite impulse response (FIR) output filters. Accordingly the web control panel control which selects the configuration of the output filters is labeled SLOPE and the options are labeled 6, 12, 18, 24 dB/octave.

  • Page 31: Fast Curve Buffer

    1 reference cycle. 3.3.16 Fast Curve Buffer The fast curve buffer is a feature common to the models 7124, 7270, and 7230 lock- in amplifiers. It allows up to 100,000 sets of eight signals to be recorded at rates of up to 1 MSa/s (1 µs per point), and supports a variety of trigger modes.
  • Page 32 Chapter 3, TECHNICAL DESCRIPTION constant amplitude, and the output filters are set to a sufficiently long time constant, the X and Y channel demodulator outputs are constant levels. The function (X ) is dependent only on the amplitude of the required signal V (t) (i.e.

  • Page 33: Main Output Processor - Noise Measurements

    Chapter 3, TECHNICAL DESCRIPTION 3.3.20 Main Output Processor - Noise Measurements The noise measurement facility uses the output processor to perform a noise computation on the X output of the demodulator. A noise buffer continuously calculates the mean level of X, representing the measured output signal, by summing the last n samples of the X output and dividing by n.

  • Page 34: Main Output Processor - Standard Curve Buffer

    This design has been updated and so the 7230 is fitted with four general-purpose DAC outputs, which can be driven from a variety of output signals, as well as the traditional programmable “auxiliary DAC”...

  • Page 35: Main Microprocessor - General

    Chapter 3, TECHNICAL DESCRIPTION 3.3.24 Main Microprocessor - General All functions of the instrument are under the control of a microprocessor, which in addition supports the computer interfaces. It also controls the instrument's 8-bit digital (TTL) programmable input/output port, which may be used for controlling auxiliary apparatus or reading the status of external logic lines.

  • Page 36: General

    Chapter 3, TECHNICAL DESCRIPTION channel. In an optical experiment, for example, this could be done by shielding the detector from the source of chopped light. 2) Execute an Auto-Offset operation, which will reduce the X channel and Y channel outputs to zero. 3) Re-establish the source of input signal.

  • Page 37: Front Panel

    Instrument Turned On and Displaying Ethernet IP Address When the model 7230 is turned on and has determined a valid IP address, either from a DHCP server, or the Auto IP address function, or is using a static address, then the Status indicator flashes as it “counts out”...
  • Page 38 An IP address consists of four numbers, each known as an octet and each of which can range from 0 t0 255. The model 7230 displays these numbers by using red and green flashes of the Status indicator, as follows. A long red flash indicates the start...

  • Page 39: Rear Panel

    4.2.01 Power Input Connector The model 7230 requires regulated DC power supply voltages of 15 V and +5 V to operate, which are provided via the SIGNAL RECOVERY Model PS0110 power supply module that plugs into this 5-pin DIN power input connector.

  • Page 40: Usb Connector

    Position Description The model 7230 uses a static IP address, as set by the command IPADDR. This command can be sent via any one of the three interfaces, but if used via the Ethernet interface and specifying a different address to that currently in use, then communications will be lost.

  • Page 41: Trig Out Connector

    Chapter 4, FRONT AND REAR PANELS positive edge only. In dual reference mode where “Rear Panel” is selected as one of the external reference inputs, a TTL reference signal (3.0 kHz or lower) should be applied to this connector. Naturally this precludes using the same input for ADC triggering at the same time.
  • Page 42 Chapter 4, FRONT AND REAR PANELS...

  • Page 43: Introduction

    3) Turn the router on. After a short delay its wireless network will be activated. 4) Using the wireless device that you want to use to control the model 7230, such as an iPad, laptop, or smartphone, find the wireless network that you have just created.
  • Page 44 Chapter 5, WEB CONTROL PANEL OPERATION Figure 5-1, Connecting to a Wireless Network 5) Connect to this network. In the example shown in figure 5-1, click the TP- LINK_POCKET_3020_ABE9A2. 6) Enter the wireless network security information, if required. In the case of the TP-Link Model TL-MR3020 the wireless security key is printed on a label fixed to the unit.
  • Page 45 Chapter 5, WEB CONTROL PANEL OPERATION Figure 5-2, Router Home Page Login Screen 9) Enter the user name and password to access the configuration page; the panel for the TP-Link Model TL-MR3020 is shown in figure 5-3 below. Figure 5-3, Router Home Page 10) Locate the DHCP information/controls page;...
  • Page 46 LAN connector of the rear panel of the model 7230. 13) Set the Config 2 switch on the rear panel of the model 7230 to position 1. This will cause the instrument to be allocated an IP address by the DHCP server in the router.
  • Page 47 In the above example the controlling computer’s IP address is 192.168.0.100 and the model 7230 has been allocated an IP address of 192.168.0.101 15) Open a new browser session and type the IP address for the model 7230 determined in section 14, which in this example is 192.168.0.101, into the address bar and press <return>.

  • Page 48: Wired Connection To A Company Or Corporate Network Using A Static Ip Address

    This is because the DHCP server in the wireless router will generally allocate the same IP address to the model 7230 each time they are both powered up and connected.
  • Page 49 Chapter 5, WEB CONTROL PANEL OPERATION Figure 5-7, Initial Browser Window 8) Type 169.254.150.230 into the address bar and press <return>. The 7230's Main Controls panel should be displayed, as shown below in figure 5-8. Figure 5-8, Model 7230 Main Controls Panel...
  • Page 50 Chapter 5, WEB CONTROL PANEL OPERATION Figure 5-9, Model 7230 Equations Panel 10) In the Command input box type IPADDR XXX XXX XXX XXX where XXX XXX XXX XXX is the static IP address given to you by your network administrator. Note that there are no periods (full stops) between the digit groups.

  • Page 51: Wired Connection To A Company Or Corporate Network Using A Dhcp Allocated Ip Address

    5) Most company and corporate networks use a domain controller, but the model 7230 cannot log onto a domain and so you will not in general be able to “see” it by browsing network resources. However, once the allocated IP address is known you will be able to access the instrument by typing this into a browser’s...
  • Page 52 Chapter 5, WEB CONTROL PANEL OPERATION This is a simple utility for a PC which searches for any model 7230's on the network. It can be downloaded from the www.signalrecovery.com website. When run, it displays the dialog shown in figure 5-12 below Figure 5-12, SRInstFinder Utility Click the Find Instruments button.
  • Page 53 STATUS light, in accordance with the information in section 4.1.04 6) Once the IP address for the 7230 has been found, type it into the browser's address bar and press <return>. The 7230's Main Controls panel should be displayed.

  • Page 54: Web Control Panels

    Chapter 5, WEB CONTROL PANEL OPERATION 5.3 Web Control Panels 5.3.01 Main Controls: Overview Figure 5-14, Main Controls Panel The Main Controls panel, shown above in Figure 5-14, is displayed when a browser session is opened on the instrument’s IP address. There are four digital indicators along the bottom of the screen, and controls for all the most common functions in the upper section.
  • Page 55 Chapter 5, WEB CONTROL PANEL OPERATION Figure 5-15, Adjusting Sensitivity Control Other controls, such as the Phase and Oscillator Frequency controls, are adjusted by typing the required value directly into a text box. Figure 5-16, Adjusting Phase Control To change the units applying to the digital indicators between “%” (percentage of full scale sensitivity) and calibrated units (e.g.
  • Page 56 The built-in Tandem Demodulation mode, which is essentially the same as dual reference mode but with the input to the second set of demodulators taken as the X- channel output from the first, allows the 7230 to make this measurement in a single instrument.

  • Page 57: Main Controls: Display Indicators

    Chapter 5, WEB CONTROL PANEL OPERATION 5.3.02 Main Controls: Display Indicators Figure 5-18, Selecting Instrument Outputs Each of the four digital indicators along the bottom of the screen can be set to display the following instrument outputs (see figure 5-18). Output Description X1 channel output.

  • Page 58: Main Controls: Input

    Chapter 5, WEB CONTROL PANEL OPERATION 5.3.03 Main Controls: Input Figure 5-20, Main Controls: Input The Input controls, shown in figure 5-20, affect the signal channel. AC Gain The AC gain control allows the AC gain to be adjusted from 0 dB to 90 dB in 6 dB steps, although not all settings are available at all full-scale sensitivity settings.
  • Page 59 Chapter 5, WEB CONTROL PANEL OPERATION bandwidth current-to-voltage converter (10E6 V/A transimpedance). B (current^8) In this setting the signal channel input is a single-ended current input connected to the BNC connector on the front panel marked B (I), and uses the low noise current-to-voltage converter (10E8 V/A transimpedance).

  • Page 60: Main Controls: Reference 1

    Chapter 5, WEB CONTROL PANEL OPERATION 60Hz Enable 60 Hz notch filter 120Hz Enable 120 Hz notch filter 60Hz + 120Hz Enable 60 and 120 Hz notch filters Demod2 source When the demodulators are configured for dual reference operation, this control selects the signal source for the second set of demodulators Sig Chan ADC In this setting the signal input to the second set of demodulators is taken from the...
  • Page 61 Chapter 5, WEB CONTROL PANEL OPERATION Analog. In this case a TTL reference at a frequency no greater than 3.0 kHz should be applied to the rear panel TRIG IN connector. External analog In this setting the reference channel is configured to accept an analog reference source applied to the front panel REF IN input connector Virtual This activates the virtual reference mode, and the Main Controls page is...

  • Page 62: Main Controls: Oscillator

    The frequency of the instrument's internal oscillator may be set, using this control, to any value between 0.001 Hz and 120.000 kHz (or 250.000 kHz if the instrument is fitted with the 7230/99 option) with a 1 mHz resolution. 5-20...

  • Page 63: Main Controls: Output 1

    Chapter 5, WEB CONTROL PANEL OPERATION 5.3.06 Main Controls: Output 1 Figure 5-24, Output 1 Controls The Output 1 controls, shown in figure 5-24, affect the first set of demodulators Sensitivity When set to voltage input mode, using the control in the Input section, the instrument's full-scale voltage sensitivity may be set to any value between 10 nV and 1 V in a 1-2-5 sequence.

  • Page 64: Main Controls: Reference 2

    Chapter 5, WEB CONTROL PANEL OPERATION Slope The roll-off of the output filters is set, using this control, to values from 6 dB to 24 dB/octave, in 6 dB steps. Note that there are some restrictions in that it is not possible to select 18 or 24 dB/octave settings at Time Constants of 500 ms or shorter when using the fast time constant mode.
  • Page 65 Chapter 5, WEB CONTROL PANEL OPERATION Source This control allows selection of the source of reference signal used to drive the reference 2 circuitry, and has three settings. The corresponding control in the Reference 1 section also offers the same choices when in dual mode:- Internal The lock-in amplifier's reference is taken from the instrument's internal oscillator.

  • Page 66: Main Controls: Output 2

    Chapter 5, WEB CONTROL PANEL OPERATION 5.3.08 Main Controls: Output 2 Figure 5-26, Output 2 Controls The Output 2 controls, shown in figure 5-26, affect the second set of demodulators Sensitivity When set to voltage input mode, using the control in the Input section, the instrument's full-scale voltage sensitivity may be set to any value between 10 nV and 1 V in a 1-2-5 sequence.

  • Page 67: Main Controls: Output Filters

    Chapter 5, WEB CONTROL PANEL OPERATION Auto Offset This control adjusts the X2 offset and Y2 offset values so that the X2 channel and Y2 channel outputs are zero. Any small residual values can normally be removed by calling Auto-Offset for a second time after a suitable delay to allow the outputs to settle.

  • Page 68: Main Controls: Status Indicators

    Dual Reference In dual reference mode the model 7230 can make simultaneous measurements at two different reference frequencies. These can be internal or external, subject to the limitation that if two external references are used, one of them cannot be greater than 3.0 kHz.

  • Page 69: Oscillator: Overview

    Chapter 5, WEB CONTROL PANEL OPERATION in the following table: Status Byte Overload Byte bit 0 command complete X(1) output overload bit 1 invalid command Y(1) output overload bit 2 command parameter error X(2) output overload bit 3 reference unlock Y(2) output overload bit 4 output overload...

  • Page 70: Oscillator: Sweep Control

    Chapter 5, WEB CONTROL PANEL OPERATION 5.3.13 Oscillator: Sweep Control Figure 5-31, Oscillator Panel, Sweep Controls The internal oscillator output in the model 7230 can be swept in frequency or amplitude, or in both parameters, using these controls. Time/Step This control defines the time per point during a frequency or amplitude sweep Start This button is used to start or stop a frequency and/or amplitude sweep.
  • Page 71 Chapter 5, WEB CONTROL PANEL OPERATION Logarithmic When this radio button is selected, the frequency is defined in terms of a percentage of the current frequency. For example, if the step size were set to 10%, the start frequency to 1 kHz and the stop frequency to 2 kHz, then the frequencies generated during the sweep would be:- 1000.000 Hz 1100.000 Hz...

  • Page 72: Oscillator: Modulation Control

    Chapter 5, WEB CONTROL PANEL OPERATION 5.3.14 Oscillator: Modulation Control Figure 5-32, Oscillator Panel, Modulation Controls The internal oscillator output in the model 7230 can be amplitude or frequency modulated using an external control voltage using the controls on this panel, shown on figure 5-32.

  • Page 73: Oscillator: Amplitude And Frequency Controls

    Chapter 5, WEB CONTROL PANEL OPERATION Voltage span This control sets the range of input voltages that will be translated into the specified frequency span. Filter control The FM control signal can be filtered by a simple digital low-pass FIR filter before being applied to the oscillator, which can be useful for eliminating noise or glitches on the signal.

  • Page 74: Rear Panel: Overview

    The frequency of the instrument's internal oscillator may be set, using this control, to any value between 0.001 Hz and 120.000 kHz (or 250.000 kHz if the instrument is fitted with the 7230/99 option) with a 1 mHz resolution. This completes the description of the Oscillator panel.

  • Page 75: Rear Panel: Dacs

    Chapter 5, WEB CONTROL PANEL OPERATION 5.3.17 Rear Panel: DACs Figure 5-34, DACs Controls These controls, shown in figure 5-34, are used to configure the signals that will appear on the four DAC connectors on the rear panel of the instrument. Each control has a signal selector;...
  • Page 76 Chapter 5, WEB CONTROL PANEL OPERATION Magnitude% (2.5V fs) In this setting the corresponding DAC connector on the rear panel of the instrument outputs a voltage related to the MAG1%fs display as follows:- MAG%fs DAC Voltage +300 7.5 V +100 2.5 V 0.0 V Phase (+9 V = +180°)
  • Page 77 Chapter 5, WEB CONTROL PANEL OPERATION RATIO DAC Voltage +7.5 7.5 V +2.5 2.5 V 0.0 V -2.5 -2.5 V -7.5 -7.5 V Log ratio When set to Log ratio the corresponding DAC connector on the rear panel of the instrument outputs a voltage related to the Log ratio calculation, which is defined as follows:- ...

  • Page 78: Rear Panel: Adcs

    Chapter 5, WEB CONTROL PANEL OPERATION Equation 2 DAC Voltage +10000 10.0 V 0.0 V -10000 -10.0 V User setting When User setting is selected the corresponding DAC connector on the rear panel of the instrument outputs the voltage set by the corresponding control, in the range 10.000 V.

  • Page 79: Rear Panel: Rs232

    Chapter 5, WEB CONTROL PANEL OPERATION to ADC4 inputs, and a radio button allows selection of two trigger modes, as follows. Internal trigger (1kHz) A conversion is performed on ADC1, ADC2, ADC3 and ADC4 every 1 ms, with the results being displayed above and being available via the computer interfaces. External trigger (1kHz) A conversion is performed on ADC1, ADC2, ADC3 and ADC4 on receipt of a rising edge at the TTL ADC TRIG IN connector on the rear panel on the instrument.

  • Page 80: Rear Panel: Ref Mon

    Prompt on When this box is checked, a prompt character is generated by the model 7230 after each command response to indicate that the instrument is ready for a new command. The prompt character is either a "*" or a "?" If a "?" is generated, it indicates that an overload, reference unlock, parameter error or command error has occurred.

  • Page 81: Rear Panel: Bind

    Chapter 5, WEB CONTROL PANEL OPERATION apply otherwise. 5.3.22 Rear Panel: Bind Figure 5-38, Bind Control When the bind control, shown in figure 5-38, is checked, it is only possible to operate the instrument using the web pages from the computer at which this box was checked.

  • Page 82: Rear Panel: Usb Status

    Position Description The model 7230 uses a static IP address, as set by the command IPADDR. This command can be sent via any one of the three interfaces, but if used via the Ethernet interface and specifying a different address to that currently in use, then communications will be lost.

  • Page 83: Equations: Overview

    Chapter 5, WEB CONTROL PANEL OPERATION 5.3.26 Equations: Overview Figure 5-42, Equations The Equations panel, shown above in Figure 5-42, allows the two user equations that are built in to the instrument to be defined, as well as giving access to a Command Interface that allows instrument commands to be sent to the unit and the response, if any, displayed.
  • Page 84 Chapter 5, WEB CONTROL PANEL OPERATION Variable Range ±30000 ±30000 MAG1 0 to +30000 PHA1 (Phase) ±18000 ADC1 ±10000 ADC2 ±10000 ADC3 ±10000 ADC4 ±10000 0 to 100000 0 to 100000 Zero Unity FRQ (Reference Frequency) 0 to 120000000 or 250000000 (Only available in position C) OSCF(Oscillator Frequency) 0 to 120000000 or 250000000...

  • Page 85: Equations: Command Interface

    Type the command in the Command input box and press <return>. The response will be shown in the Command response box. In the figure above, the command ID was sent and the response is "7230", the instrument's model number. 5.3.29 Equations: Auto Default...
  • Page 86 Chapter 5, WEB CONTROL PANEL OPERATION 5-44...

  • Page 87: Introduction

    Windows HyperTerminal. 6.3.02 General Features The RS232 interface in the model 7230 is implemented with three wires; one carries digital transmissions from the computer to the lock-in amplifier, the second carries digital transmissions from the lock-in amplifier to the computer and the third is the Logic Ground to which both signals are referred.

  • Page 88: Choice Of Baud Rate

    In the model 7230 the baud rate can be set to a range of different values up to 38,400, corresponding to a minimum time of less than 0.25 ms for a single character.

  • Page 89: Handshaking And Echoes

    Where the RS232 parameters of the terminal or computer are capable of being set to any desired value, an arbitrary choice must be made. In the model 7230 the combination set at the factory is even parity check, 7 data bits, and one stop bit (fixed).

  • Page 90: Delimiters

    Chapter 6, COMPUTER OPERATION byte) is set, in which case the terminator is <CR>. The default (power-up) state of this bit is zero. 6.3.08 Delimiters Most response transmissions consist of one or two numbers followed by a response terminator. Where the response of the lock-in amplifier consists of two numbers in succession, they are separated by a byte called a delimiter.

  • Page 91: Usb Operation

    VISA software driver is the need to download and install the complete VISA environment in order to use the driver. Readers should refer to the document “USB Drivers for the Model 7124, 7230, and 7270 Lock-in Amplifiers”, available from the www.signalrecovery.com website, for further information about installing these drivers.

  • Page 92: Delimiters

    Chapter 6, COMPUTER OPERATION When USBTERM has been set to 1, the terminator bytes are, in the following order: 1) A null character (ASCII 0) 2) A byte representing the value of the Status Byte (table 6-1) 3) A byte representing the value of the Overload Byte (table 6-1) In the case of commands that generate a single response, the controlling program should send the null-terminated command string to the instrument and then read the response bytes sent back from it until the null is detected.

  • Page 93: Sockets

    Chapter 6, COMPUTER OPERATION network can then access it, simply by typing the IP address in the address bar. As discussed in section 5.4, this will open the Main Controls remote front panel. 6.5.04 Sockets The instrument normally accepts commands sent to sockets 50000 or 50001 on its IP address.

  • Page 94: Delimiters

    Chapter 6, COMPUTER OPERATION while in the binary dump mode it needs to know exactly how many bytes to read, since the data itself can contain null characters. Only by doing this can the program be prevented from requesting more data from the socket than the lock-in has actually sent.

  • Page 95: Command Descriptions

    Chapter 6, COMPUTER OPERATION 6.7 Command Descriptions This section lists the commands in logical groups, so that, for example, all commands associated with setting controls which affect the signal channel are shown together. Appendix G gives the same list of commands but in alphabetical order. 6.7.01 Signal Channel IMODE [n] Current/Voltage mode input selector...
  • Page 96 Chapter 6, COMPUTER OPERATION DCCOUPLE [n] Input coupling control The value of n sets the input coupling mode according to the following table: Coupling mode AC coupled DC coupled SEN [n] SEN. Full-scale sensitivity control The value of n sets the full-scale sensitivity according to the following table, depending on the setting of the IMODE control: full-scale sensitivity IMODE=0...

  • Page 97: Reference Channel

    Chapter 6, COMPUTER OPERATION maximize the X channel output and minimize the Y channel output. ACGAIN [n] AC Gain control Sets the gain of the signal channel amplifier according to the following table:- AC Gain AC Gain 0 dB 48 dB 6 dB 54 dB 12 dB...
  • Page 98 Chapter 6, COMPUTER OPERATION Selection INT (internal) EXT TTL (external front panel REF input) EXT ANALOG (external front panel REF input) This command is invalid in Dual Reference mode IE1 [n] Reference channel 1 source control, Dual Reference In Dual Reference mode, the value of n sets the reference channel 1 source according to the following table: Selection INT (internal)

  • Page 99: Signal Channel Output Filters

    Chapter 6, COMPUTER OPERATION Auto-Phase (auto quadrature null) The instrument adjusts the reference phase to maximize the X channel output and minimize the Y channel output signals. FRQ[.] Reference frequency meter If the lock-in amplifier is in the external reference source modes, the FRQ command causes the lock-in amplifier to respond with 0 if the reference channel is unlocked, or with the reference input frequency if it is locked.
  • Page 100 Chapter 6, COMPUTER OPERATION synchronous time constant control is turned off, the fast analog output mode is turned on (FASTMODE 1), and the output filter slope is set to 12 dB/octave if it had previously been 18 or 24 dB/octave. NNBUF [n] Noise Buffer Length control The value of n sets the noise buffer length according to the following table:...

  • Page 101: Signal Channel Output Amplifiers

    Chapter 6, COMPUTER OPERATION SLOPE [n] Output low-pass filter slope (roll-off) control When the fast analog output mode and noise measurement mode are turned off (FASTMODE 0 and NOISEMODE 0), the selection is according to the following table: Slope 6 dB/octave 12 dB/octave 18 dB/octave 24 dB/octave...

  • Page 102: Instrument Outputs

    Operation is the same as earlier SIGNAL RECOVERY lock-in amplifiers, such as the models 7220, 7225, 7265, 7265, 7280, 5209 and 5210. Operation is the same as earlier versions of firmware in the models 7270, 7124 and 7230 MP[.] Magnitude, phase This returns the MAG and PHA outputs separated by the defined delimiter.
  • Page 103 Chapter 6, COMPUTER OPERATION RT[.] Ratio output In integer mode the RT command reports a number equivalent to 1000×X/ADC1 where X is the value that would be returned by the X command and ADC1 is the value that would be returned by the ADC1 command. In floating point mode the RT.
  • Page 104 Chapter 6, COMPUTER OPERATION according to the following table: Variable Range X or X1 ±30000 Y or Y1 ±30000 MAG or MAG1 0 to 30000 PHA or PHA1 ±18000 ADC1 ±10000 ADC2 ±10000 ADC3 ±10000 ADC4 ±10000 0 to 100000 0 to 100000 10 0 zero...

  • Page 105: Internal Oscillator

    Chapter 6, COMPUTER OPERATION 6.7.06 Internal Oscillator OA[.] [n] Oscillator amplitude control In fixed point mode n sets the oscillator amplitude in microvolts rms. The range of n is 0 to 5000000 representing 0 V to 5 V rms. In floating point mode n sets the amplitude in volts. ASTART[.] [n] Oscillator amplitude sweep start amplitude Sets the start amplitude for a subsequent sweep of the internal oscillator amplitude,...
  • Page 106 Chapter 6, COMPUTER OPERATION Linear sweep n In fixed point mode, n is the step size in millihertz. In floating point mode n is in hertz. The range of n is 0 to 120 or 250 kHz Linear seek sweep n In fixed point mode, n is the step size in millihertz.
  • Page 107 Chapter 6, COMPUTER OPERATION Function Oscillator amplitude/frequency modulation disabled Oscillator amplitude modulation enabled Oscillator frequency modulation enabled AMCENTERV[.] [n] Oscillator amplitude modulation center voltage command The value of n sets the oscillator amplitude modulation center voltage; in fixed point mode n is an integer in the range -10000 to +10000, corresponding to voltages from - 10.000 V to +10.000 V, and in floating point mode it is in volts.

  • Page 108: Analog Outputs

    120.0 or 250.0 kHz and the center frequency must be greater than or equal to the span frequency. For example, with an instrument fitted with the 7230/99 upper frequency extension option and a 125 kHz center ...

  • Page 109: Digital I/O

    Chapter 6, COMPUTER OPERATION Signal (DAC2) Y1 % (2.5 V FS) Noise % (2.5 V FS) Ratio: (10 × X1%/ADC 1) (10  X1%/ADC1) Log Ratio: log Equation 1 Equation 2 User DAC2 Ext ADC1 monitor Phase2 : +9 V = +180°, -9 V = -180° (dual mode only) Signal (DAC3) Magnitude1 % (2.5 V FS) Noise % (2.5 V FS)

  • Page 110: Auxiliary Inputs

    Chapter 6, COMPUTER OPERATION status All lines configured as outputs D0 = input, D1 - D7 = outputs D1 = input, D0 and D2 - D7 = outputs D2 = input, D0 - D1 and D3 - D7 = outputs D3 = input, D0 - D2 and D4 - D7 = outputs D4 = input, D0 - D3 and D5 - D7 = outputs D5 = input, D0 - D4 and D6 - D7 = outputs...
  • Page 111 Chapter 6, COMPUTER OPERATION CBD [n] Curve buffer define for Standard Mode Buffer Defines which data outputs are stored in the standard curve buffer when subsequent TD (take data), TDT (take data triggered) or TDC (take data continuously) commands are issued. Up to 17 (or 22 in dual reference and dual harmonic modes) curves, or outputs, may be acquired, as specified by the CBD parameter.
  • Page 112 Chapter 6, COMPUTER OPERATION sensitivity and the IMODE setting, are needed, is to allow the instrument to transfer the acquired curves to the computer in floating point mode. Without this information, the unit would not be able to determine the correct calibration to apply. Note that the CBD command directly determines the allowable parameters for the DC, DCB and DCT commands.
  • Page 113 Chapter 6, COMPUTER OPERATION Start condition Sample condition Stop condition Ext rising edge Points = LEN On command Ext rising edge Points = LEN Ext falling edge Points = LEN On command Ext falling edge Points = LEN Ext rising edge On HC command On command Ext rising edge...
  • Page 114 Chapter 6, COMPUTER OPERATION Halt curve acquisition Halts curve acquisition in progress. It is effective during both single (data acquisition initiated by TD command) and continuous (data acquisition initiated by TDC command) curve acquisitions. The curve may be restarted by means of the TD, TDT or TDC command, as appropriate.
  • Page 115 Chapter 6, COMPUTER OPERATION been sent, equivalent to asserting bits 0 and 2, then the X and Magnitude outputs would be stored. The permitted values of n would therefore be 0 and 2, so that DC 0 would transfer the X channel output curve and DC 2 the Magnitude curve. NOTE: When transferring the Frequency curve, which is saved when bit 15 in the CBD parameter is asserted, the instrument automatically reads the data for each stored point in both frequency curves (i.e.
  • Page 116 Chapter 6, COMPUTER OPERATION Curves 15 and 16 store the reference frequency in millihertz. When using the DCB command (although not with the other curve transfer commands), both curves need to be transferred separately. They should then be converted to two arrays of integer values, allowing for the fact that the data points in curve 15 are unsigned 16-bit values, while those in curve 16 are signed 2’s complement 16-bit values (although in practice they are never negative).

  • Page 117: Computer Interfaces

    Chapter 6, COMPUTER OPERATION Bit Decimal value Output and range X Output (±10000 FS) Y Output (±10000 FS) Magnitude Output (0 to +10000 FS) Phase (±18000 = ±180°) Sensitivity setting (1 to 27) + IMODE (0, 1, 2, 3 = 0, 32, 64, 128) Noise (0 to +10000 FS) Ratio (±10000 FS)
  • Page 118 Chapter 6, COMPUTER OPERATION bit number bit negated bit asserted data = 7 bits data = 8 bits no parity bit 1 parity bit even parity odd parity echo disabled echo enabled prompt disabled prompt enabled DD [n] Define delimiter control The value of n, which can be set to 13 or from 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)
  • Page 119 IP address e.g. 169.254.0.10 When sent with the four parameters, the command sets the IP address that will be used when the model 7230 is set to static IP address mode (via the rear panel Config Switch 2, see section 4.2.07) The parameters are separated by a space character and not by a dot, e.g.

  • Page 120: Instrument Identification

    6.7.12 Instrument Identification Identification Causes the lock-in amplifier to respond with the number 7230. Report firmware version Causes the lock-in amplifier to respond with the firmware version number, as also displayed on the Configuration menu.

  • Page 121: Dual Mode Commands

    Chapter 6, COMPUTER OPERATION 6.7.14 Dual Mode Commands When either dual reference or dual harmonic modes are selected, some commands change so that both channels can be controlled independently, as listed in the following table: Single Reference or Dual Reference or Virtual Reference mode command Dual Harmonic mode command not available...

  • Page 122: Programming Examples

    Chapter 6, COMPUTER OPERATION 6.5 Programming Examples 6.5.01 Introduction This section gives some examples of the commands that need to be sent to the lock- in amplifier for typical experimental situations. 6.5.02 Basic Signal Recovery In a typical simple experiment, the computer is used to set the instrument controls and then to record the chosen outputs, perhaps as a function of time.

  • Page 123: And Y Output Curve Storage Measurement

    Chapter 6, COMPUTER OPERATION TC 11 Set time constant to 50 ms Auto-Phase The frequency sweep would be performed and the outputs recorded by sending the following commands from a FOR...NEXT program loop: OF. XX Set oscillator frequency to new value XX hertz Software delay of 200 ms (4 ×...
  • Page 124 Chapter 6, COMPUTER OPERATION 6-38...

  • Page 125: Appendix A, Specifications

    Specifications Appendix Measurement Modes  X In-phase  Y Quadrature The unit can simultaneously show any  R Magnitude four of these outputs on the front panel   Phase Angle display  Noise nF, n  127 Harmonic Dual Harmonic Simultaneously measures the signal at two different harmonics F and F...
  • Page 126 Appendix A, SPECIFICATIONS Current Input Mode Low Noise (10 V/A) or Wide B/W (10 V/A) Full-scale Sensitivity Low Noise 10 fA to 10 nA in a 1-2-5 sequence Wide Bandwidth 10 fA to 1 µA in a 1-2-5 sequence Frequency Response (-3dB) 0.001 Hz ...
  • Page 127 Appendix A, SPECIFICATIONS Acquisition Time Internal Reference instantaneous acquisition External Reference 2 cycles + 1 s Reference Frequency Meter Resolution 4 ppm or 1 mHz, whichever is the greater Demodulators and Output Processing Output Zero Stability Digital Outputs No zero drift on all settings Displays No zero drift on all settings DAC Analog Outputs...
  • Page 128 Appendix A, SPECIFICATIONS Auxiliary Inputs ADC 1, 2, 3 and 4 Maximum Input ±11 V Resolution 1 mV Accuracy ±20 mV Input Impedance 1 M // 30 pF Sample Rate 200 kHz maximum (one ADC only) Trigger Mode Internal, External or burst Trigger Input TTL compatible, rising or falling edge Outputs...
  • Page 129 Appendix A, SPECIFICATIONS General Power Via external model PS0110 universal power supply Voltage 100 - 240 VAC Frequency 47 - 63 Hz Power 40 VA max Dimensions Width 15½" (390 mm) Depth 10" (250 mm) Height With feet 3" (75 mm) Without feet 2½"...
  • Page 130 Appendix A, SPECIFICATIONS...

  • Page 131: Appendix B, Pinouts

    Pinouts Appendix B.1 RS232 Connector Pinout Figure B-1, RS232 Connector (Female) Function Description Data In Data Out Signal Ground Request to Send - always +12 V All other pins are not connected B.2 Digital I/O Port Connector Figure B-3, Digital I/O Port Connector 8-bit TTL-compatible port.
  • Page 132 Appendix B, PINOUTS Function Ground +5 V D0 = Least Significant Bit D7 = Most Significant Bit...

  • Page 133: Appendix C, Cable Diagrams

    Appendix C.1 RS232 Cable Diagrams Users who choose to use the RS232 interface to connect the model 7230 lock-in amplifier to a standard serial port on a computer will need to use one of two types of cable. The only difference between them is the number of pins used on the connector which goes to the computer.
  • Page 134 Appendix C, CABLE DIAGRAMS Figure C-2, Interconnecting RS232 Cable Wiring Diagram...

  • Page 135: Auto Default Function

    Default Settings Appendix Auto Default Function The Auto-Default computer commands ADF 1 or ADF 2 set the model 7230's controls as follows:- General Full-scale sensitivity 200 mV AC Gain 0 dB Time constant 100 ms Oscillator frequency 1000.000 Hz Oscillator amplitude...
  • Page 136 Logic zero The Auto-Default function on the Rear Panel web control page and the ADF 0 computer command set the model 7230's controls and output displays as above, and in addition sets the communications interface parameters as follows:- RS232 Settings...
  • Page 137 Appendix D, DEFAULT SETTINGS Ethernet Settings (Note: These only apply if the CONF1G switch 1 is set to position "0") IP Address 169.254.150.230 Subnet Mask 255.255.255.000 Default Gateway 000.000.000.000...
  • Page 138 Appendix D, DEFAULT SETTINGS...
  • Page 139 Alphabetical Listing of Commands Appendix Fast Data Transfer command The ? command offers a method of reading a combination of instrument outputs which are sampled at the same time, thereby ensuring that they are correlated. The response to the ? command is the output(s), expressed in floating point mode, specified by the present setting of the Curve Buffer Define (CBD) command (see section 6.7.09) and separated by delimiter character(s) defined by the DD command.

  • Page 140: Appendix E, Alphabetical Listing Of Commands

    Appendix E, ALPHABETICAL LISTING OF COMMANDS AMDEPTH [n] Oscillator amplitude modulation dept control The value of n sets the oscillator amplitude modulation depth in percent, from 0 to AMFILTER [n] Oscillator amplitude modulation filter control command The value of n sets the oscillator amplitude modulation voltage low-pass filter control in the range 0 to 10.
  • Page 141 Appendix E, ALPHABETICAL LISTING OF COMMANDS in the range 0 to 5.000 V In fixed point mode, n is in microvolts rms and in floating point mode n is in volts AUTOMATIC [n] AC Gain automatic control Status AC Gain is under manual control, either using the Main Controls panel or the ACGAIN command Automatic AC Gain control is activated, with the gain being adjusted according to the full-scale sensitivity setting...
  • Page 142 Appendix E, ALPHABETICAL LISTING OF COMMANDS Bit Decimal value Output and range Ratio (±10000 FS) Log ratio (-3000 to +2000) ADC1 (±10000 = ±10.0 V) ADC2 (±10000 = ±10.0 V) 1024 ADC3 (±10000 = ±10.0 V) 2048 ADC4 (±10000 = ±10.0 V) 4096 DAC1 (±10000 = ±10.0 V) 8192...
  • Page 143 Appendix E, ALPHABETICAL LISTING OF COMMANDS Signal (DAC1) X1% (2.5 V FS) Noise % (2.5 V FS) Ratio: (10 × X1%/ADC 1) (10  X1%/ADC1) Log Ratio: log Equation 1 Equation 2 User DAC1 Main signal channel ADC output (digital signal monitor 1) Magnitude2 % (2.5 V FS) (dual mode only) Signal (DAC2) Y1 % (2.5 V FS)
  • Page 144 Appendix E, ALPHABETICAL LISTING OF COMMANDS mode Standard Fast DAC[.] n Set user DAC output voltage controls The first parameter n , which specifies the DAC, is compulsory and is either 1, 2, 3 or 4. The value of n specifies the voltage to be output.
  • Page 145 Appendix E, ALPHABETICAL LISTING OF COMMANDS Output and range X Output (±10000 FS) Y Output (±10000 FS) Main signal channel ADC output (digital signal monitor 1 ADC1 (±10000 = ±10.0 V) ADC2 (±10000 = ±10.0 V) Dual modes only:- Output (±10000 FS) Output (±10000 FS) Input to second demodulator (digital signal monitor 2) The computer program's subroutine which reads the responses to the DC command...
  • Page 146 Appendix E, ALPHABETICAL LISTING OF COMMANDS Reference Frequency = (65536 × value in Curve 16) + (value in Curve 15) The computer program's subroutine which reads the responses to the DCB command needs to be able to handle the potentially very large data blocks (200 k bytes in the case of one 100 k curve) that can be generated.
  • Page 147 Appendix E, ALPHABETICAL LISTING OF COMMANDS Decimal value Output and range X Output (±10000 FS) Y Output (±10000 FS) Magnitude Output (0 to +10000 FS) Phase (±18000 = ±180°) Sensitivity setting (1 to 27) + IMODE (0, 1, 2, 3 = 0, 32, 64, 128) Noise (0 to +10000 FS) Ratio (±10000 FS)
  • Page 148 Appendix E, ALPHABETICAL LISTING OF COMMANDS Parameter n is used to set the addition/subtraction operator in the numerator according to the following table:- Operator Subtraction Addition The parameters n and n specify the variables A, B, C and D respectively according to the following table: Variable Range...
  • Page 149 Appendix E, ALPHABETICAL LISTING OF COMMANDS EVENT [n] Event marker control During a curve acquisition into the standard curve buffer, 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.
  • Page 150 120.0 or 250.0 kHz and the center frequency must be greater than or equal to the span frequency. For example, with an instrument fitted with the 7230/99 upper frequency extension option and a 125 kHz center ...
  • Page 151 169.254.0.1 When sent with the four parameters, the command sets the gateway address that will be used when the model 7230 is set to static IP address mode (via the rear panel Config Switch 2, see section 4.2.07) The parameters are separated by a space character and not by a dot, e.g.
  • Page 152 Appendix E, ALPHABETICAL LISTING OF COMMANDS IE [n] Reference channel source control (Internal/External) In Single Reference and Dual Harmonic mode, the value of n sets the reference input mode according to the following table: Selection INT (internal) EXT TTL (external front panel REF input) EXT ANALOG (external front panel REF input) This command is invalid in Dual Reference mode IE1 [n]...
  • Page 153 Appendix E, ALPHABETICAL LISTING OF COMMANDS When sent with the four parameters, the command sets the IP address that will be used when the model 7230 is set to static IP address mode (via the rear panel Config Switch 2, see section 4.2.07) The parameters are separated by a space character and not by a dot, e.g.
  • Page 154 Appendix E, ALPHABETICAL LISTING OF COMMANDS In floating point mode, the LR. command reports a number equivalent to log(X/ADC1). The response range is -3.000 to +2.079 Curve acquisition status monitor Causes the lock-in amplifier to respond with four values that provide information concerning data acquisition, as follows: First value, Curve Acquisition Status: a number with five possible values, defined by the following table:...
  • Page 155 Appendix E, ALPHABETICAL LISTING OF COMMANDS Bit 0 X channel output overload (> ±300 %FS) Bit 1 Y channel output overload (> ±300 %FS) Bit 2 X2 channel output overload (> ±300 %FS) Bit 3 Y2 channel output overload (> ±300 %FS) Bit 4 CH1 output overload Bit 5...
  • Page 156 Operation is the same as earlier SIGNAL RECOVERY lock-in amplifiers, such as the models 7220, 7225, 7265, 7265, 7280, 5209 and 5210. Operation is the same as earlier versions of firmware in the models 7270, 7124 and 7230 PORTDIR [n] Digital port direction control The value of n determines which of the eight lines on the digital port are configured as inputs and which as outputs.
  • Page 157 Appendix E, ALPHABETICAL LISTING OF COMMANDS status D7 = input, D0 - D6 outputs All lines configured as inputs READBYTE Read digital port input The response to the READBYTE command is an integer between 0 and 255 representing the binary value of all eight lines of the instrument rear panel digital port.
  • Page 158 Appendix E, ALPHABETICAL LISTING OF COMMANDS The lowest five bits in n control the other RS232 parameters according to the following table: bit number bit negated bit asserted data = 7 bits data = 8 bits no parity bit 1 parity bit even parity odd parity echo disabled...
  • Page 159 255.255.0.0 When sent with the four parameters, the command sets the subnet mask that will be used when the model 7230 is set to static IP address mode (via the rear panel Config Switch 2, see section 4.2.07) The parameters are separated by a space character and not by a dot, e.g.
  • Page 160 Appendix E, ALPHABETICAL LISTING OF COMMANDS Bit 0 Command complete Bit 1 Invalid command Bit 2 Command parameter error Bit 3 Reference unlock Bit 4 Output overload - read overload byte to determine location Bit 5 New ADC values available after external trigger Bit 6 Input overload Bit 7...
  • Page 161 Appendix E, ALPHABETICAL LISTING OF COMMANDS SYNC [n] Synchronous time constant control Effect Synchronous time constant disabled Synchronous time constant enabled TADC [n] Auxiliary analog-to-digital input trigger mode The value of n sets the trigger modes for the auxiliary ADC inputs according to the following table: Trigger Mode Internal (1 kHz)
  • Page 162 Appendix E, ALPHABETICAL LISTING OF COMMANDS buffer using the SWEEP command with a parameter of 9, 10 or 11, then this sweep will be started as well. TDC n Take data continuously Initiates data acquisition. Acquisition starts at the current position in the curve buffer and continues at the rate set by the STR command until halted by an HC command or on receipt of a trigger at the TRIG in connector, in accordance with the following table:...
  • Page 163 Appendix E, ALPHABETICAL LISTING OF COMMANDS Trigger Trigger generated once per curve, at start of curve Trigger generated once per point TRIGOUTPOL [n] Curve buffer trigger output polarity The value of n defines the polarity of the trigger output generated when a buffer acquisition is run in accordance with the following table: Trigger Output Rising-edge...
  • Page 164 Appendix E, ALPHABETICAL LISTING OF COMMANDS XOF [n X channel output offset control Selection Disables offset Enables offset facility The range of n is ±30000 corresponding to ±300% full-scale. XY[.] X, Y channel outputs This returns the X and Y outputs separated by the defined delimiter. Y[.] Y channel output In fixed point mode causes the lock-in amplifier to respond with the Y demodulator...
  • Page 165 Index Index ? command 6-18, E-1 introduction 3-15 8-bit programmable output port 3-15 AUTOMATIC [n] command 6-11, E-3 A input connector 4-1 Auxiliary ADC's 4-5 AC Gain AXO command 6-15, E-3 and dynamic reserve 5-21 B (I) input connector 4-1 and full scale sensitivity 3-5 Block diagram 3-2 and input overload 3-5, 3-13...
  • Page 166 INDEX trigger output 4-5 Auto Measure 5-43 DAC[.] n ] command 6-23, E-6 Command interface 5-43 DAC1 Equation 1 and Equation 2 5-41 and user equations 5-42 overview 5-41 connector 4-5 Ethernet Connection Methods 5-1 control 5-33 Ethernet interface DAC2 IP Address 6-6 and user equations 5-42 main controls 6-6...
  • Page 167 INDEX shield control 5-17 Center frequency control 5-30 Inspection 2-1 Center voltage control 5-30, 5-31 IPADDR [n1 n2 n3 n4] command 6-33, E-14 Enable AM control 5-31 IPLOCK command 6-33, E-15 Enable FM control 5-30 IPUNLOCK command 6-33, E-15 Ext ref as source control 5-31 Key specifications 1-3 Filter control 5-31 LAN connector 4-3...
  • Page 168 INDEX PHA[.] command 6-16, E-18 choice of parity check option 6-2 PHASEPOL [n] command 6-16, E-18 connector 4-3 PORTDIR [n] command 6-23, E-18 delimiter control 5-38 Power input connector 4-3 echo on control 5-38 Power switch 4-3 general features 6-1 Power-up defaults 3-16 handshaking and echoes 6-3 PS0110 power supply 2-1...
  • Page 169 INDEX Tandem demodulation mode VER command 6-34, E-25 described 3-1 Virtual reference Tandem demodulation mode Search button 5-20 described 5-14 Start Freq control 5-19 Tandem demodulation mode Step size control 5-19 described 5-26 Stop Freq control 5-19 Tandem demodulator mode 5-18 Time/Step Freq control 5-20 TC [n] command 6-14, E-23 Virtual reference mode...
  • Page 170 INDEX INDEX-6...
  • Page 171 This Warranty shall not apply to any instrument or component not manufactured by AMETEK Advanced Measurement Technology, Inc. When products manufactured by others are included in AMETEK Advanced Measurement Technology, Inc equipment, the original manufacturers Warranty is extended to AMETEK Advanced Measurement Technology, Inc customers.

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