Tektronix TriMode P7700 Series Technical Reference page 14

Theory of operation
Probe components
2
P7700 Series probes are comprised of a probe compensation box (comp box),
a TekFlex connector for attaching probe tips, and an interconnect cable that
transfers measured signals, power, and control signals between the probe comp
box and the TekFlex connector probe head. A P7700 Series probe tip must be
inserted into the TekFlex connector probe head to make the final connection to
the DUT (device under test).
Probe compensation box. The probe compensation box assembly mates to the
host instrument through an intelligent TekConnect probe interface. Power,
control signals, and the signal measured by the probe are transferred to and from
the oscilloscope through the TekConnect interface. The comp box includes a
membrane toggle switch to select the TriMode input mode for probe tips that
support TriMode functionality:
Differential (A–B)
A input (single-ended to ground)
B input (single-ended to ground)
Common-mode ((A+B)/2 to ground)
The probe input mode can also be selected using the oscilloscope probe controls or
Probe Setup menu. The Probe Setup menu is also used to adjust the probe Offset A
and Offset B voltage settings and to initiate a DC Probe Compensation operation.
All other P7700 Series probe internal controls are handled automatically through
communication between the probe and oscilloscope.
An LED on the top panel of the comp box indicates the selected input mode.
Another LED indicates when a warning condition exists. Warnings are caused
when parameters such as input voltages exceed the safe limits of the probe.
A mechanical latch and optional retention thumbscrew hold the probe securely to
the instrument during use. The thumbscrew is only intended to be finger-tightened,
and is machined to prevent tools from being used to over-torque it. To remove
the probe, loosen the thumbscrew counterclockwise, depress the latch button to
release the probe, and then pull out the probe.
CAUTION.
To prevent damage to the probe, use care when handling the probe.
Rough or careless use can damage the probe.
Main interconnect cable. This cable assembly consists of a pair of matched,
low-loss coaxial signal cables that carry the acquired signal from the probe head to
the probe comp box. The cable assembly includes an 8-conductor bundle of wires
that supply probe tip head power and control signals from the probe comp box
through the TekFlex connector interface. Some of the wires carry bidirectional
data, such as queries and responses about the type of probe tip attached to the
TekFlex connector, and other probe tip-specific information.
P7700 Series TriMode Probes Technical Reference