SRS Labs SR510 - Manual (Page 17)

13
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
<1
Ω
. 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
7 Signal ground
8 Digital 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 -
10.24 V to +10.24 V and the resolution is 2.5 mV.
The input impedance is 1 M
Ω
. 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
2.5 mV. The output impedance is <1
Ω
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