Download Agilent Technologies E1476A 64-Channel, 3-Wire

Switchbox
Measurements
The multiplexer can be configured in switchbox configuration to perform
voltage, 2-wire ohms, 4-wire ohms or temperature measurements via the
internal analog bus. Measurements can be made using switching or
scanning methods.
• Switching. All measurements can be made by individually
switching the channels with CLOSe and OPEN commands.
Individually switching the channels requires that you also close
appropriate tree relay(s) to connect channels to the analog bus.
• Scanning. All measurements can be made by scanning a list of
channels. The advantage of scanning is that the appropriate tree
relays are closed automatically when you scan a channel list
with the SCAN command and set SCAN:PORT ABUS.
NOTE
Multiplexer Reset
Conditions
See "Switching Applications" for examples of measurements using
switching methods. See "Scanning Applications" for examples of
measurements using scanning methods.
At power-on or following the reset of the multiplexer (*RST command), all
64 channels and the tree relays are open. In addition, after a *RST
command, the current scan channel list is invalidated. Table 2-1 lists the
parameters and default values for the functions following turn-on or reset.
Table 2-1. E1476A Default Conditions for Power-on and Reset
Parameter
40 Switchbox Applications
Default
Description
ARM:COUNt
1
Number of scanning cycles is one.
TRIGger:SOURce
IMM
Advances through a scanning list
automatically.
INITiate:CONTinuous
OFF
Number of scanning cycles is set
by ARM:COUNt
OUTPut[:STATe]
OFF
Trigger output from EXT, TTL, or
ECL sources is disabled.
[ROUTe:]SCAN:MODE
NONE
Channel list is set for volts
measurement.
[ROUTe:]SCAN:PORT
NONE
Analog bus connections are
disabled from channels.
Channel state
All 64 channels are open (channels 00 - 63)
Tree relay state
All tree relays are open (channels 90 - 94)
Channel list from SCAN
command (after *RST)
Current channel list is invalidated following a
reset of the module with *RST command.
Chapter 2