Keysight 34921A-34925A User’s Guide 43
This module is interlock protected, which means whenever the D-sub connector
end of the modules is exposed, the Analog Bus relays immediately open and
disconnect from the Analog Bus. For more information, see “Safety Interlock” on
page 11.
Lifetime of relays is severely degraded as current or voltage goes up. If higher
voltage is being switched, limits on source current are recommended.
When the power is off, all channel and Analog Bus relays open.
34924A Simplified Schematic
Because user-attached reactive loads and backplane parasitic capacitance
may result in high in-rush currents, 100
Ω
in-rush resistors protect the reed
relays from damage and performance degradation. Therefore, you must
consider these resistors when you are designing a measurement. Refer to the
simplified schematic on page 43.