Theory of Operation 5
Keysight 34970A/34972A Service Guide 151
34901A
Components in this discussion are located on the A1 circuit assembly
(34901-66501).
The control circuitry has four groupings of latches, relay drivers and relays. The
three control lines (SEL_A, SEL_B, and SEL_C) from the module controller are
divided into five control lines by the binary to octal converter U109.