34933A Dual/Quad 4X8 Reed Matrix - Keysight Technologies 34980A Service Manual

34933A Dual/Quad 4x8 Reed Matrix

Using program commands or the front panel of the 34980A, you can configure the
34933A dual/quad 4x8 reed matrix module for differential (2-wire) mode or
single-ended (1-wire) mode.
The 34933A module contains 100 Ω in-rush resistors that are used to protect the
reed relays from reactive loads. If you have applications where in-rush resistors
interfere with measurements, connections are provided on the terminal blocks for
you to bypass the in-rush resistors that are located on the columns.
Two-Wire Mode
In 2-wire mode, the 34933A module contains two matrices, each with 32 2-wire
crosspoint non-latching reed relays organized in a 4- row by 8-column
configuration. Every row and column are made up of two wires each, a high (H)
and a low (L). Each crosspoint relay has a unique channel number representing
the row and column that intersect to create the crosspoint. For example, channel
308 represents the crosspoint connection between row 3 and column 08 (all
columns consisting of two digits; in this case the digits are 08). See the simplified
schematic on
One-Wire Mode
In 1-wire mode, the 34933A module contains four matrices (1 through 4), each
with 32 1-wire crosspoint non- latching reed relays organized in a 4-row by
8-column configuration. Every row and column has one wire each. Each
crosspoint relay has a unique channel number representing the matrix, and the
single-wire row and column that intersect to make the crosspoint. For example,
channel 218 represents Matrix 2, row 1 and column 8. See the simplified
schematic on
Keysight 34980A Service Guide
page 106.
page 107.
Troubleshooting and Diagnostics 4
105