2 – 12
Introduction
Near the center of the instrument, in the “CONTROL INHIBIT”
block, is a large locking toggle switch. When in the upper position,
none of the front-panel (or remote) interface functions are operable.
The analog signal processing of the SR124 remains fully functioning
while the Inhibit switch is up, but no controls will respond. For nor-
mal operation, the Inhibit switch should be left in the lower position.
Where applicable, the corresponding remote command is listed,
along with the page where it is defined, in parentheses, like this:
(
FORM
, 4 – 11 ).
2.3.1
Signal input section
The left-hand section of the instrument comprises the “Signal Input”.
See Figure 2.3 for detail.
Stanford Research Systems
RESERVE
SENSITIVITY
SIGNAL INPUT
INPUT FILTER
100
200
500
A
A/I
B
Signal
Monitor
nV
mV
Q-factor
µV
AC
DC
10 MΩ
10 MΩ
600 Ω
Ground
Flat
Notch
Low Noise
Normal
High Res.
Low Pass
High Pass
Band Pass
Float
OVLD
OVLD
A–B
I (10
6
)
I (10
8
)
1
1
1
2
5
10
20
50
100
2
2
5
5
10
10
20
20
50
50
100
100
200
200
500
500
depth
f trim
kHz
Hz
Push to select
Hold to
null
10% ENBW
Input
Ground
Type
Reserve
Couple
BNC
knob
knob
knob
BNC
BNC
Figure 2.3: The SR124 front panel signal input section.
2.3.1.1
Signal input
User input signals are applied to the SR124 through the “A
/
I”, or the
“A
/
I” and “B” BNC connectors. The input configuration is controlled
SR124
Analog Lock-In Amplifier