Filter
Top Products
E-7
Appendix E, ALPHABETICAL LISTING OF COMMANDS
EX [n] Output expansion control
Expands X and/or Y outputs by a factor of 10. Changes meter, CH1 and CH2
outputs full-scale to ±10 % if X or Y selected. The value of n has the following
significance:
n Expand mode
0Off
1 Expand X
2 Expand Y
3 Expand X and Y
FET [n] Voltage mode input device control
The value of n selects the input device according to the following table:
n Selection
0 Bipolar device, 10 kΩ input impedance, 2 nV/√Hz voltage noise
1 FET, 10 MΩ input impedance, 5 nV/√Hz voltage noise
FLOAT [n] Input connector shield float / ground control
The value of n sets the input shield switch according to the following table:
n Selection
0 Ground
1 Float (connected to ground via a 1 kΩ resistor)
FNF [n] Reference harmonic mode control
The value of n sets the reference channel to one of the NF modes, or restores it to the
default F mode according to the following table:
n Mode selected
1 The lock-in amplifier measures signals at the reference frequency F
2 The lock-in amplifier measures at 2F
3 The lock-in amplifier measures at 3F
FRQ[.] Reference frequency meter
If the lock-in amplifier is in the EXT or EXT LOGIC reference source modes, the
FRQ command causes the lock-in amplifier to respond with 0 if the reference channel
is unlocked, or with the reference input frequency if it is locked.
If the lock-in amplifier is in the INT reference source mode, it responds with the
frequency of the internal oscillator.
In fixed point mode the frequency is in mHz.
In floating point mode the frequency is in Hz.