Teledyne LeCroy PXA125 - Manual (Page 69)

User Manual PXA125
ArbConnection 3-55
Normal color of the digital reading is dark blue. If
you modify the reading, the color changes to a
lighter shade of blue, indicating that the PXA125
has not been updated yet with the new parameter.
Pressing Execute will update the instrument and
will restore the color of the digital readout to dark
blue, indicating that the displayed value is the
same as the generator setting.
Also note that the digital readout has an autodetect
mechanism for the high and low limits. You cannot
exceed the limits if you are using the dial but only
if you use the keypad. In case you do, the program
will not let you download an illegal parameter and
you’ll be requested to correct your setting.
Besides the grouped buttons and parameters, there are two other
buttons on the right top corner of this panel. These buttons will
provide back access to the Main Panel and will also allow removal of
the Waveforms Panel from the screen.
10 MHz Ref The 10 MHz Ref group provides selection between internal or external
references. The PXA125 has three reference options:
Internal – connects the CLK10 reference from P2 to the sample clock
generator. The accuracy and stability of the CLK10 is around
100ppm.
Note
Compact PCI chassis do not have P2 connectors
on their backplanes. If you have a CPCI chassis
and intend to use the PXA125, you have two
options: 1) Apply a 10 MHz reference to the 10 MHz
Ref input, or 2) Use the TCXO setting with your
card. If you fail to provide an appropriate reference
signal, the instrument will not function properly.
External – connects the front panel 10MHz Reference Input to the
sample clock generator. The accuracy and stability of this input is
determined by the source, which you apply to this input.
TCXO – connects a 1ppm reference to the sample clock input. Click
on the Internal button to select the Internal CLK10 reference, the
External button to activate the external reference input, or the TCXO
to select the 1 ppm reference.