Auto Functions - Stanford Research Systems SR844 User Manual

4-20 Auto Functions

Auto Functions
AWRS
ACRS
AGAN
APHS
AOFF ch,q
SR844 RF Lock-In Amplifier
The AWRS command performs the Auto Wide Reserve function. This command is
the same as pressing Shift–WideReserveDown. AWRS automatically sets the
Wide Reserve Mode of the instrument to the minimum reserve without overload.
The ACRS command performs the Auto Close Reserve function. This command is
the same as pressing Shift–CloseResrv.
The AGAN command performs the Auto Sensitivity function. This command is the
same as pressing Shift–SensUp. AGAN automatically sets the Sensitivity of the
instrument.
This function may take some time if the time constant is long. This function does
nothing if the time constant is greater than one second. Check the Interface Ready
bit (bit 1) in the Serial Poll Status to determine when the command is finished.
The APHS command performs the Auto Phase function. This command is the same
as pressing Shift−Phase. This command adjusts the reference phase so that the
current measurement has a Y value of zero and an X value equal to the signal
magnitude, R.
The AOFF ch,q command automatically offsets the chosen quantity to zero. The
quantity is specified by its display channel ch and quantity q as per the table
above. Both parameters ch and q are required. This command is equivalent to
pressing the Auto Offset key.
ch,q Quantity
1,0 X
1,1 R[V]
1,2 R[dBm]
2,0 Y
Important!
Remember, Auto Offset X or Y performs Auto Offset on both X and Y.