Specifications

Multiple multiplexers can connect
to the built-in analog buses, allowing
you to scan up to 560 2-wire channels
or 640 1-wire channels in a single
mainframe. The 34921A also offers
4 channels for directly measuring
current. Or if you need more current
channels, shunts can be added to the
terminal block for easy current
measurements.
The multiplexer modules feature
break-before-make connections to
ensure that no two signals are con-
nected to each other during a scan.
Or, if you prefer, you can control
switching manually to create your
own switch configuration. All the
multiplexer switches have a relay
counter to help predict when relays
need to be replaced.
8
Figure 4. 34925A 40/80-channel optically isolated FET mux (shown in 1-wire mode bank 2)
ABus1 DMM (MEAS) ABus2 DMM (SENS) ABus3 ABus4
071
072
073
074
075
076
077
078
079
080
H
061
062
063
064
065
066
067
068
069
070
H
051
052
053
054
055
056
057
058
059
060
H
041
042
043
044
045
046
047
048
049
050
H
911
LH
921
LH
LH
912
LH
922
LH
913
LH
923
LH
914
LH
924
LH
Figure 3. 34922A 70-channel armature multiplexer (bank 1 shown)
002
003
004
005
007
HL
HL
006
009
010
011
012
014
911
HL
912
HL
913
HL
914
013
016
017
018
019
021
020
023
024
025
026
028
027
030
031
032
033
035
034
ABus1 DMM (MEAS) ABus2 DMM (SENS) ABus3 ABus4