SRS Labs Lock-In Amplifier, SR530 manual Status Byte, Errors, Bit

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X n {,v}

n designates one of the 6 general purpose analog ports located on the rear panel. If n is 1,2,3, or 4, the X command will return the voltage on the designated analog input port (X1-X4) in volts. If n is 5 or 6, then v may also be sent. If v is included, the designated analog output port (X5 or X6) will be set to v volts where v has the range -10.238V to +10.238V. If v is absent, the output value of the selected port is returned. On power-up, port X5 is the ratio output. An "X 5" command will read the ratio output. An "X 5" command with the parameter v will set port X5 to v volts, overriding the ratio output. Port X5 will return to the ratio output on power-up or reset.

Y {n}

The Y command reads the status byte. (See the following section for a definition of the Status Byte.) n designates one bit, 0-7, of the status byte. If n is included, the designated bit of the status byte is returned. The bit which is read is then reset. If n is absent, the value of the entire byte is returned and all status bits are then reset. This status byte may also be read over the GPIB using the serial poll command.

Z

The Z command causes an internal reset. All settings return to the default values shown on page 15. The ERR LED will be on for about three seconds to indicate that the stored instrument settings are being ignored. If the RS232 echo mode is on, the sign-on message is sent over the RS232 interface.

Status Byte

The SR530 maintains an 8-bit status register which the user may read to obtain information on the unit's status. The status byte may be read in two ways: by sending the Y command, which returns the value of the byte in ASCII coded decimal, or, when using the GPIB, by performing a serial poll. The returned status byte reflects all of the status conditions which have occurred since the last time the byte was read. After the status byte has been read, it is cleared. Thus, the status byte should be read initially to clear all previous conditions (especially after a power up or after settings have been changed).

The definitions for each bit of the status byte are given below:

Bit 0

Not Used

Bit 1

Command Parameter Out of Range. This bit is set if a parameter associated with a command is not in the allowed range.

Bit 2

No Reference. This bit is set when no reference input is detected, either because the amplitude is too low or the frequency is out of range.

Bit 3

Unlock. This bit is set when the reference oscillator is not locked to the reference input. If there is no reference input, bit 2 (no reference) will be set but bit 3 (unlock) may not be.

Bit 4

Overload. This bit is set if there is a signal overload. This can happen when the sensitivity is too high, the dynamic reserve is too low, the offset is on, or the expand is on. Overloads on the general purpose A/D inputs or the ratio output are not detected.

Bit 5

Auto Offset Out of Range. This bit is set if the auto offset function cannot zero the output because the output exceeded 1.024X full scale.

Bit 6

SRQ. This bit is set if the SR530 has generated an SRQ on the GPIB interface. This bit is reset after the SR530 has been serial polled. This bit is set only for status reads via a serial poll, ie., Bit 6 always zero for the RS232 .

Bit 7

Command Error. This bit is set when an illegal command string is received.

Errors

Whenever a 'parameter out of range' or an 'unrecognized command' error occurs, the appropriate status bits are set and the ERR LED flashes. In addition, any commands remaining on the current command line (up to the next <cr>) are lost. The ERR LED will also light if any of the internal communication buffers overflows. This occurs when 240 characters are pending on the command queue or output queue. The ERR LED will go off as soon as all buffers drop below 200

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Contents Model SR530 Page Table of Contents Appendix C Gpib Operating NON-OPERATINGPage SR530 Specification Summary Demodulator GpibFront Panel Summary Enbw Abridged Command List Configuration Switches Status Byte DefinitionSignal Inputs Signal FiltersSR510 Guide to Operation Front Panel SensitivityDynamic Reserve StatusDisplay Select Channel 1 DisplayOutput Output ChannelRel Channel Offset ChannelRcosø Output Expand ChannelChannel 2 Display Auto Phase Reference Input Rsinø OutputTrigger Level Reference Mode Phase ControlsReference Display Time ConstantDefaults PowerLocal and Remote SR530 Guide to Operation Rear Panel Page Command Syntax SR530 Guide to ProgrammingCommunicating with the SR530 Front Panel Status LEDsRS232 Echo and No Echo Operation Try-Out with an Ascii TerminalSR530 Command List LOW Norm HighN1,n2,n3,n4 Page Status Byte ErrorsBit Reset Trouble-Shooting Interface ProblemsCommon Hardware Problems include Common Software Problems includeSR530 with the RS232 Interface SR530 with the Gpib InterfaceGpib with RS232 Echo Mode Serial Polls and Service RequestsSR530 with Both Interfaces Lock-in Technique Measurement ExampleUnderstanding the Specifications Shielding and Ground LoopsPage Page SR530 Block Diagram Signal Channel Phase Sensitive DetectorsReference Channel DC Amplifiers and System GainCircuit Description Reference Oscillator Demodulator and Low Pass AmplifierAnalog Output and Control ExpandFront Panel Microprocessor ControlRS232 Interface Power SuppliesGpib Interface Amplifier and Filter Adjustments Multiplier AdjustmentsCalibration and Repair Notch Filters Replacing the Front-End TransistorsAppendix a Noise Sources and Cures Non-Essential Noise SourcesPage Page Case 1 The Simplest Configuration Appendix B Introduction to the RS232Baud Rate Case 2 RS232 with Control LinesStop Bits ParityVoltage Levels Final TipAppendix C Introduction to the Gpib Bus DescriptionAppendix D Program Examples Program Example IBM PC, Basic, via RS232Program Example IBM PC, Microsoft Fortran v3.3, via RS232 Page Program Example IBM PC, Microsoft C v3.0, via RS232 #include stdio.hPage Program Example 4 IBM PC,Microsoft Basic, via Gpib ′INCREMENT X6 Output by 2.5 MV Program Example HP85 via Gpib Documentation Oscillator Board Parts List PC1SW1 DpdtMain Board Parts List BR1BR2 BT1SR530 Component Parts List SR530 Component Parts List 22U MIN PIN DGpib Shielded CX1FU1 CY1MPSA18 SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List 4PDT SPSTX8SR513 Assy SR530 Component Parts List Z80A-CPU Static RAM, I.CTIE Anchor TranscoverMica #4 FlatFront Panel Board Parts List RED LD2 LD1LD3 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.
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