Probe Cal
TDS 620A, 640A, & 644A User Manual
Table 3-6: Probe Cal Status
Probe User Type Probe Connected2
Cal’d?1Action Simple Interface3Complex Interface4
No Doesn’t
Matter
Initialized Initialized
Yes Power
off
Initialized
(probe data is retained)
Initialized
(probe data is retained)
Yes Power
on Can not detect different probe: Display
Re-use
Probe Calibration Data
menu
Different probe:
Initialized
Cal’d Probe:
Pass
Different probe:
Initialized
Yes Disconnect
Probe
Initialized Initialized
Yes Connect
Probe Can not detect different probe: Display
Re-use
Probe Calibration Data
menu
Different probe:
Initialized
Cal’d Probe:
Pass
Different probe:
Initialized
1Refers to a channel input that was
successfully
compensated at the time Probe Cal was last executed for the input channel.
2If no probe is connected, the probe status in the vertical main menu is always
initialized.
3A probe with a simple interface is a probe that can convey very limited information to the oscilloscope. Most passive probes (includ-
ing those shipped with this instrument) have simple interfaces.
4A probe with a complex interface is a probe that can convey additional information. For instance, it might automatically set the
oscilloscope input channel impedance to match the probe, send the oscilloscope a unique probe identification number, etc. Some
optical probes and most active probes (such as the optional accessory P6205) have complex interfaces.