Appendix D:

Program Examples

All of the program examples which follow do the same thing, only the computer, language, or interface is changed. The programs read the Channel 1 and 2 Outputs and write the results to the computer screen. In addition, the X6 analog output port is ramped from 0 to 10V.

Program Example 1:

IBM PC, Basic, via RS232

In this example, the IBM PC's ASYNC port (known as COM1: or AUX: to DOS users) will be used to communicate with the SR530. 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.

10 ′ EXAMPLE PROGRAM TO READ THE SR510 OUTPUT AND RAMP THE X6 ANALOG OUTPUT 20 ′ USING IBM PC BASICA AND THE COM1: RS232 PORT.

30 ′ THE RAMP ON X6 CAN BE WATCHED BY SETTING THE SR530 DISPLAY TO A/D.

40

50

60′ ON THE REAR PANEL OF THE SR530, SET SWITCH #1 OF SW2 DOWN

70 ′ AND ALL OTHER SWITCHES IN SW2 UP. (9600 BAUD, NO PARITY)

80

90 OPEN ″COM1:9600,N,8,2,CS,DS,CD″ AS #1

 

100

′ SET UP COM1: PORT TO 9600

BAUD, NO PARITY,

8 DATA BITS, 2 STOP BITS,

110

IGNORE

CTS

(CLEAR TO SEND),

DSR (DATA SET READY),

120

AND CD

(CARRIER DETECT).

 

130

140 PRINT #1, ″ ″ ‘CLEAR UART BY SENDING SPACES

150PRINT #1, ″Z″ ′RESET SR530

160

FOR

I = 1 TO 200: NEXT

I

′WAIT FOR RESET TO FINISH

170

 

 

′INIT

X6 OUTPUT TO ZERO

180

X

=

0

190

200

PRINT #1,

″Q1″

′READ OUTPUT

210

INPUT #1,V1

′INTO V1

220

PRINT

#1,

″Q2″

′READ

OUTPUT

230

INPUT

#1,V2

′INTO

V2

240

250

PRINT ″CH1 = ″;V1;″

CH2 = ″;V2

260

 

′INCREMENT X6

OUTPUT BY 2.5 MV

270

X =X

+ .0025

280

IF X

> 10 THEN X = 0

′RESET X6 RAMP

290

PRINT #1, USING ″X6, ##.###″;X

′SET X6 OUTPUT VOLTAGE

300

 

′LOOP FOREVER

 

310

GOTO

200

 

46

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SRS Labs Lock-In Amplifier, SR530 manual Appendix D Program Examples, Program Example IBM PC, Basic, via RS232

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.