Stanford Research Systems SR844, User Manual

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Overview 3-7
SR844 RF Lock-In Amplifier
AUX OUT 2 A second auxiliary DC output voltage, identical to AUX OUT 1.
AUX IN 1
This is an auxiliary DC/low-frequency input voltage which can be
digitized by the SR844. The range is
±
10.5 V and the resolution is 16 bits
(approx. 0.3 mV). The input impedance is 1 M
Ω
and the bandwidth is
limited to about 3 kHz. The SR844 can report this voltage just like a
digital voltmeter, or the voltage can be used to normalize the signal in
ratio mode.
AUX IN 2 A second auxiliary DC/low-frequency input voltage, identical to
AUX IN 1.
Factory Preset Values
The factory preset values may be set by pressing
Shift–Recall
, or by sending the
*RST
command over either remote interface. The factory preset values are:
Reference/ Phase Scan/ Rel
Reference Source Internal Scan Start 100 kHz
Internal Frequency 1.00 MHz Scan Stop 100 MHz
Input Impedance 50
Ω
Number of Steps 4
Reference Display Frequency Scan Mode Off
Reference Phase
0
°
Rel Values Not Set
Rel Mode Off
RF Signal Input Aux Outputs
Input Impedance
50
Ω
AUX OUT 1 0.000 V
Wide Reserve Normal AUX OUT 2 0.000 V
Gain /Time Constant Remote Interfaces
Sensitivity 1 Vrms Output to GPIB
Close Reserve Normal GPIB Address 8
Time Constant 100 ms RS-232 Baud Rate 9600
Filter dB/oct 12 dB Parity None
Override Remote On
Output/ Offset Other
CH1 Output X Alarms On
CH2 Output Y Key-Click On
CH1 Display X Status Enable Registers Cleared
CH2 Display Y Save/ Recall Memories Cleared
All Offsets 0.00 %
All Expands
×
1 Data Storage
Ratio Mode Off Sample Rate 1 Hz
Scan Mode Loop
Trigger Starts No