Agilent Technologies L4400 manual One-Wire Mode

L4433A Dual/Quad 4x8 Reed Matrix 5

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 125.

In 1- wire mode, the L4433A 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 124.

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 row 1 and row 2 respectively to the HI (H) and LO (L) lines of ABus1 and ABus2.

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 116 of this chapter.

When the power is off, matrix relays and analog bus relays open.

L4400 User’s Guide 119