Agilent Technologies Agilent 34980A, User Manual

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178 34980A User’s Guide
5
Matrix Switch Modules
One-Wire Mode
To physically configure the module in 1- wire mode, use the 34933T- 002
terminal block,
or a compatible standard or custom cable. If using a
standard or custom cable, make sure you connect interlock pins 17 and
33 on the Matrix 2 D- sub connector. Refer to the pinout drawing and
table on
page 184 .
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
page 183 .
In 1- wire mode, you can close no more than 40 channels simultaneously
due to power dissipation. For example, with one Analog Bus relay closed
you can close up to a maximum of 39 channel relays. If you try to close
more than the allowed number of channels, you will receive an error
message.
You can connect any combination of inputs and outputs at the same
time. However, only Matrix 3 and Matrix 4 in 1- wire mode of this module
connect to the Analog Buses. By closing channels 921 and 922 you can
connect rows 1 and rows 2 respectively to the internal DMM of the
34980A mainframe for voltage and resistance measurements.
You can connect multiple matrix modules externally and/or through the
Analog Buses for applications that require large matrices. For
information on linking multiple matrix modules, refer to
page 166 of this
chapter.
When the power is off, matrix relays and Analog Bus relays open.