Programming instructions

74 Verification Tests
Agilent 44478A/B Verification Tests
Agilent 44478A/B consists of two 4-to-1 MUXs (Group 00 & Group 10) that
can switch signals bidirectionally. Each group has a separate ground for
isolation between groups and this ground is unswitched (Figure 4-7).
To verify that the relays in each group are functioning, verify continuity
between the center conductor of the common BNC and each channel’s BNC
center conductor when that channel is closed. If no continuity exists, verify
that a relay is stuck open and continuity exists from the channel’s BNC
center conductor and the channel’s associated SMB (J101-J110) center
conductor when the channel is open.
Figure 4-7. Agilent 44478A/B Simplified Schematic
3
CH00
CH01
J101
3
J102
3
CH02
CH03
J104
3
J105
COM00
3
GROUP 00
4
CH11
CH10
J106
4
J107
4
CH12
CH13
J109
4
J110
COM10
GROUP 10
BNC CONNECTOR
SMB CONNECTOR
ChXX
R
TYPICAL CHANNEL RESISTIVE TERMINATIONS
FOR 44478A, R=50
FOR 44478B, R=75
Ω
Ω