28 Keysight 34921A-34925A Low Frequency Multiplexer Modules User’s Guide
Low Frequency Multiplexer Modules 34923A 40/80-Channel Reed Multiplexer
34923A 40/80-Channel Reed Multiplexer
The 34923A 40/80-Channel Reed Multiplexer (40/80-Ch Reed MUX) is divided
into two equal banks of non-latching reed switches. This module also contains
eight armature Analog Bus relays (channels 911-914 and 921-924), four on each
bank that can connect the bank relays to the system Analog Buses. You can
connect any of the channels to the internal DMM through ABus1 and ABus2 for
voltage or resistance measurements.
Using program commands or the mainframe front panel, you can control each of
the channel switches individually, and configure this module for differential
(2-wire or 4-wire) or single-ended (1-wire) mode. Refer to the simplified
schematics on page 31 and page 35.
If you are using an Keysight 34923T-00x terminal block to connect your DUT to
this module, be sure to use the terminal block that corresponds to your module
configuration mode (Refer to the terminal block drawings on page 34 and
page 38.):
You can confirm the mode in which your module is configured by using the
SYSTem:CTYPe? <slot number> program command. This command
returns the identity of the plug-in module in the specified slot.
In all modes, this module has capability to scan as many as 500 channels/second
using the internal DMM. With the automatic “break-before-make” connection
operation, you are assured that no two signals are connected to each other
during a scan.
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 and the D-Sub connector drawings on page 32 and page 36.
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.
34923T-001 (Option 001 Terminal block for differential (two- or four-wire) mode
34923T-002 (Option 002) Terminal block for single-ended (1-wire) mode
Whenever you change from 2- or 4-wire mode to 1-wire
mode, or the reverse, you must cycle power on the 34980A
for the configuration to take effect.
Because user-attached reactive loads and backplane
parasitic capacitance may result in high in-rush currents,
100
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 schematics on page 31 and page 35.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
To Next Page
Loading...
