Agilent Technologies E8462A, User Manual

Page: 38 / 156

36 Using the Multiplexer
Switching or Scanning
There are two general ways to use the E8462A Relay Multiplexer. First, you
can use the
ROUTe:FUNCTion command subsystem (see Chapter 3) to set
up the multiplexer in any of its 12 operating modes: 1-Wire (1-1X256,
2-1X128, 4-1X64, 8-1X32), 2-Wire (1-2X128, 2-2X64, 4-2X32, 8-2X16),
3-Wire (1-3X64), or 4-Wire (1-4X64, 2-4X32, 4-4X16). You can then use
the [
ROUTe:]CLOSe or [ ROUTe:]OPEN commands to control individual
channel relays. In the 2-Wire, 3-Wire, and 4-Wire modes, banks of channels
are paired together such that when you close one channel the paired relay(s)
also close automatically. The
ROUTe command subsystem automatically
closes the appropriate tree relays depending on the multiplexer mode.
Alternately, you can set the multiplexer mode and scan through a list of
channels. Scanning involves sequentially closing/opening channels in a
channel list. Use the ROUTe:SCAN command to set the scan mode, use the
analog bus, and specify the channel in the channel list.
The channel list used in the
ROUTe
command subsystem includes the 256
channel relays (CH000-255). Valid channel numbers depend on the
specified mode. The 22 tree relays (CH9000-9021), the nine routing relays
(CH9100-9108) and five analog bus connection control relays (CH9200-
9204) are automatically set depending on the specified mode.
Note
You must specify the Multiplexer’s operating mode with the
[ROUTe:]FUNCtion command before executing the [ROUTe:]
CLOSe,
OPEN , or SCAN functions. This closes the appropriate tree relays
configuring the module for the specified mode. See the ROUTe command
in Chapter 3 for more details. Also, Figure 1-6 on page 20, Figure 1-7 on
page 21, and Figure 1-8 on page 22 show the valid channel and front panel
connections for 1-, 2-, 3- and 4-wire modes.
Note
Pay special attention to the valid channel numbers when you execute these
SCPI commands. Refer to the comments of the ROUTe subsystem
commands in Chapter 3 for more information of the
paired channel and
valid channel numbers .
Switching Channels
to the Analog Bus
When the multiplexer FUNCtion is set to one of the WIREn modes (any
mode but NONE), the appropriate tree relays are automatically closed at the
close channel command connecting the channel to the appropriate terminal
bus line (Ter0-Ter15). To use the analog bus, however, you must execute the
ROUTe:SCAN:PORT command. The analog bus relays will automatically
close and open when a scanning operation is executed and the mode is not
NONE. Only the tree relays needed for the closed channel are closed. All
others are opened. All tree relay and channel realys are opened when power
is removed from the module, the module is reset with the *RST command
or ROUTe:FUNCtion NONE is executed reconfiguring the module. These
actions also open all other relays that are closed. You must manually close
the tree relays, routing relays and analog bus relays when you specify the
FUNCtion to be NONE.