Atec Agilent-34980A - Manual (Page 8)

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
L H
921
L H
L H
912
L H
922
L H
913
L H
923
L H
914
L H
924
L H
Figure 3. 34922A 70-channel armature multiplexer (bank 1 shown)
002
003
004
005
007
H L
H L
006
009
010
011
012
014
911
H L
912
H L
913
H L
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