SR510 Guide to Operation Rear Panel

AC Power

The ac line voltage selector card, line fuse, and line cord receptacle are located in the fuse holder at the left side of the rear panel. See the section, Preparation for Use at the front of this manual for instructions on setting the ac voltage selector and choosing the correct fuse.

GPIB Connector

The SR530 has an IEEE 488 (GPIB) interface built in. The GPIB address is set using SW1 located to

the right of the interface connectors. Refer to page 7 for switch setting details.

RS232 Connector

The SR530 has an RS232 interface. The connector is configured as a DCE. The baud rate, parity, stop bits, and echo mode are selected using SW2 located to the right of the interface connectors. Refer to Page 7 for switch setting details.

Signal Monitor Output

This BNC provides the buffered output of the signal amplifiers and filters. This is the signal just before the demodulator. The output impedance is <1Ω . When a full scale input is applied, the peak- to-peak amplitude at this output is 20 mV, 200 mV or 2 V for dynamic reserve settings of high, norm, and low, respectively.

Preamp Connector

This 9 pin "D" connector provides power and control signals to external peripherals such as pre- amplifiers. The available power is described below.

Pin

Voltage

Current Available

1

+20

100 mA

2

+5

10 mA

6

-20

100 mA

7Signal ground

8Digital ground

General Purpose A/D and D/A

There are four analog input ports, labeled X1 through X4. These inputs may be digitized and read via the computer interfaces. The range is -

10.24V to +10.24 V and the resolution is 2.5 mV. The input impedance is 1 MΩ . A digitization can be performed in about 3 mS but the result may take longer to transmit over the interface being used.

There are two analog output ports, labeled X5 and X6. The voltages at these ports may be programmed via the computer interfaces. The range is -10.24 V to +10.24 V and the resolution is

2.5mV. The output impedance is <1Ω and the output current is limited to 20 mA.

Ratio

Output X5 is the ratio output when not programmed by the computer interface or set via the front panel. X5 becomes the ratio output whenever the unit is turned on.

The voltage at X5 is the ratio of the detected signal output, X, to the analog voltage at port X1. An output of 10 V corresponds to a ratio of 1. The ratio is computed by digitizing the demodulator output and the voltage at port X1 and then taking the ratio. The resolution is 0.0025 V. For best accuracy, the sensitivity should be set to provide at least a 50% full scale signal and the analog denominator (X1) should be 5V or greater. The ratio is updated approximately every 1.5 mS. For the Ratio feature to work, the voltage at the denominator input must exceed 40 mV.

Internal Oscillator

The INTERNAL OSCILLATOR is a voltage controlled oscillator with a sine wave output . To use the oscillator as the reference source, connect the REF OUTPUT on the rear panel to the REF INPUT on the front panel. The REF OUTPUT is a 1 Vrms sine wave. The SINE OUTPUT may be used as the stimulus to the experiment. The SINE

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