Service manual

Agilent E1346A
Multiplexer
Description
The Agilent E1346A 48-Channel Single Ended Relay Multiplexer consists
of an E1346A component assembly (E1346-66201) and a terminal block.
The multiplexer provides switching (multiplexing) for 48 channels
(channels 00 to 47). Each channel switches only a high (HI) connection. The
Low (LO) and Guard (G) connections are common for all channels. The
Low and Guard are switched, however, by the tree switches. See Figure 4-1
for a block diagram of these modules.
Component
Assembly
Description
The E1346A Component Assembly consists of 16 channel relays and four
tree switch relays. Each channel relay switches three HI channels to the tree
switch relays.
The AT, BT, and CT Tree Switch relays control which of the three channels
connected by a channel relay are connected to the Voltage Sense common
terminals and the Analog Bus Connector. Additionally, the Tree Switches
connect LO and G to common. HI, LO, and G are all provided 100
Ω
protection resistors on the component assembly.
The DT Tree Switch relay connects the Current Source terminals to the
Voltage Sense Terminals and Analog Bus connector. HI, LO, and G are
switched and provided with 100
Ω protection resistors on the component
assembly.
Terminal Block
Description
The terminal block provides connections from user devices to the
multiplexer. The terminal block also provides connections for multimeters,
voltmeters, counters, and other measuring devices.
The Terminal Block has:
• 48 terminals for channel HI
• three terminals for channel LO
• three terminals for channel G
• three terminals for Current Source HI, LO ,and G
• three terminals for Voltage Sense HI, LO, and G.
4-2 Service