SRS Labs SR530, Lock-In Amplifier manual Program Example IBM PC, Microsoft Fortran v3.3, via RS232

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Program Example 2:

IBM PC, Microsoft Fortran v3.3, via RS232

Machine language routines to interface to the COM1: RS232 port are provided in the file RS232.OBJ found on the SR575 disk. These routines allow for simple interfacing to the SR530 at 19.2 kbaud from FORTRAN programs.

To use these routines, the file 'for232.inc' (also on the SR575 disk) must be 'included' in the FORTRAN source.

Only two wires between the IBM PC's ASYNC port and the SR530 are needed (pins #2 & #3 of the RS232), but pins 5,6,8 and 20 should be connected together on the connector at the IBM end.

$storage:2

$include: ′for232.inc′

[

for 232.inc must be included to call subroutines in RS232.OBJ

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link with RS232.OBJ (on SR565 disk)

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RS232.OBJ defines:

[

init

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initializes COM1: to 19.2 kbaud

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txstr (str) str is a string terminated with ′$′

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transmits str to COM1:

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rxstr (str) str must be declared with length of 15 or greater

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fills str with string received from COM1:

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if and error occurs, nocom is called.

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Nocom should be a FORTRAN subroutine in your program.

 

program ex2

 

character *20 str1,str2, str3

[

Example program to read the SR530 outputs and ramp the

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X6 analog output using Microsoft FORTRAN v3.3 and the

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COM1: port. Set all switches in SW2 to UP on SR530

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for 19.2 kbaud.

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The ramp on X6 can be watched by setting the SR530

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display to D/A/

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initialize COM1: port to 19.2 kbaud

 

call init

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set character wait interval to zero

 

call txstr(′w0$′)

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reset X6 to zero

 

x6=0.0

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read channel 1 output into string variable str1

20

call txstr(′q1$′)

 

call rxstr(str1)

[

read channel 2 output into string variable str2

 

call txstr(′q2$′)

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Contents Model SR530 Page Table of Contents Appendix C Gpib NON-OPERATING OperatingPage SR530 Specification Summary Gpib DemodulatorFront Panel Summary Enbw Abridged Command List Status Byte Definition Configuration SwitchesSensitivity Signal InputsSignal Filters SR510 Guide to Operation Front PanelChannel 1 Display Dynamic ReserveStatus Display SelectOffset Channel OutputOutput Channel Rel ChannelExpand Channel Rcosø OutputChannel 2 Display Auto Phase Rsinø Output Reference InputTrigger Level Time Constant Reference ModePhase Controls Reference DisplayPower DefaultsLocal and Remote SR530 Guide to Operation Rear Panel Page Front Panel Status LEDs Command SyntaxSR530 Guide to Programming Communicating with the SR530Try-Out with an Ascii Terminal RS232 Echo and No Echo OperationLOW Norm High SR530 Command ListN1,n2,n3,n4 Page Errors Status ByteBit Common Software Problems include ResetTrouble-Shooting Interface Problems Common Hardware Problems includeSR530 with the Gpib Interface SR530 with the RS232 InterfaceSerial Polls and Service Requests Gpib with RS232 Echo ModeSR530 with Both Interfaces Measurement Example Lock-in TechniqueShielding and Ground Loops Understanding the SpecificationsPage Page SR530 Block Diagram DC Amplifiers and System Gain Signal ChannelPhase Sensitive Detectors Reference ChannelCircuit Description Demodulator and Low Pass Amplifier Reference OscillatorMicroprocessor Control Analog Output and ControlExpand Front PanelPower Supplies RS232 InterfaceGpib Interface Multiplier Adjustments Amplifier and Filter AdjustmentsCalibration and Repair Replacing the Front-End Transistors Notch FiltersNon-Essential Noise Sources Appendix a Noise Sources and CuresPage Page Case 2 RS232 with Control Lines Case 1 The Simplest ConfigurationAppendix B Introduction to the RS232 Baud RateFinal Tip Stop BitsParity Voltage LevelsBus Description Appendix C Introduction to the GpibProgram Example IBM PC, Basic, via RS232 Appendix D Program ExamplesProgram Example IBM PC, Microsoft Fortran v3.3, via RS232 Page #include stdio.h Program Example IBM PC, Microsoft C v3.0, via RS232Page Program Example 4 IBM PC,Microsoft Basic, via Gpib ′INCREMENT X6 Output by 2.5 MV Program Example HP85 via Gpib Documentation Dpdt Oscillator Board Parts ListPC1 SW1BT1 Main Board Parts ListBR1 BR2SR530 Component Parts List SR530 Component Parts List CX1 22U MINPIN D Gpib ShieldedCY1 FU1MPSA18 SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SPSTX8 4PDTSR513 Assy SR530 Component Parts List Static RAM, I.C Z80A-CPU#4 Flat TIE AnchorTranscover MicaFront Panel Board Parts List RED LD1 LD2LD3 Quad Board Parts List SR530 Component Parts List PC1 SR530 Component Parts List Miscellaneous Parts List SR530 Component Parts List

SR530, Lock-In Amplifier specifications

The SRS Labs Lock-In Amplifier, model SR530, is a powerful tool designed for high-precision measurements in the realm of scientific research and industrial applications. This state-of-the-art instrument excels in extracting small signals from noisy environments, making it an invaluable asset for experiments in fields such as physics, engineering, and materials science.

One of the main features of the SR530 is its ability to perform synchronous detection, which is key to improving signal-to-noise ratios. By utilizing a reference signal, the device correlates the incoming signal with the reference to effectively filter out noise, allowing for the accurate measurement of weak signals that might otherwise be obscured. This process of phase-sensitive detection is fundamental to the operation of the Lock-In Amplifier.

The SR530 offers a wide frequency range, covering from 0.1 Hz to 100 kHz. This broad frequency response allows it to handle a diverse array of signals, making it suitable for various applications including optical detection, capacitance measurements, and in many cases, voltammetry. The device is also equipped with multiple inputs and outputs, facilitating the integration with other laboratory equipment and enabling complex experimental setups.

Precision is further enhanced with its adjustable time constant, which allows users to optimize the response time based on experimental needs. The user can choose time constants from 10 microseconds to 10 seconds, accommodating fast dynamic measurements as well as those requiring stability over longer durations.

Another remarkable characteristic of the SR530 is its digital processing capabilities. The device features a highly accurate digital voltage measurement system, minimizing drift and ensuring long-term stability. Additionally, the use of microprocessors enhances data handling and allows for features such as programmable settings, facilitating automated measurements.

Moreover, the SR530 includes a range of output options, including analog outputs, which can be used for direct signal processing, as well as digital interfaces for integration with computers. This ensures that users can not only capture high-fidelity data but also analyze and display it efficiently.

In conclusion, the SRS Labs SR530 Lock-In Amplifier stands out due to its sophisticated technology, versatile features, and robust performance. Its precision, flexibility, and ease of use make it an ideal choice for researchers and engineers looking to unlock the potential of weak signal measurement in complex environments.