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3-2
NOTE
To maintain 75
Ω
characteristic imped-
ance, close only one channel per multi-
plexer bank simultaneously. Closing more
than one channel per multiplexer may
cause unexpected results. Program the
Model 7001/7002 for restricted operation
to avoid closing more than one channel at
a time.
Opening individual channels
To open a closed channel, simply key in the desired chan-
nel(s), then press OPEN. Closing channels 1, 5, and 9 will
open all other channels. OPEN ALL performs the same func-
tion.
Using OPEN ALL
OPEN ALL will open all channels except channels 1, 5, and
9. Since those three channels are normally closed, OPEN
ALL will close channels 1, 5, and 9.
NOTE
If channels 1, 5, and 9 are closed, all re-
maining channels will open, but the dis-
play will not update reflecting these
current open channels. Conversely, if
OPEN ALL is used to open all channels,
channels 1, 5, and 9 will close automati-
cally, but the display will not update to re-
flect these closed channels. Executing a
scan list will update the display to reflect
the current state of the relay card.
3.3.2 Scanning channels
To scan through channels, first configure a scan list, then pro-
gram the Model 7001/7002 to perform a scan sequence. You
can create a scan list in the same manner as you would a
channel list. First, however, press the SCAN LIST key to se-
lect the "SCAN CHANNEL" mode, then enter the desired
channels to be included in the scan list. For example, the fol-
lowing list scans channels 2, 3, 6, and 10 through 12 of a
Model 7038 installed in slot 2:
SCAN CHANNELS 2!2, 2!3, 2!6, 2!10-2!12
Note that channels are scanned in the order they appear in the
scan list.
To perform a manual scan, first select the RESET default
conditions in the SAVESETUP selection of the main MENU.
Press STEP to take the mainframe out of the idle state, then
manually scan through channels by pressing the STEP key.
For information on more complex scan sequences, refer to
the Model 7001 or 7002 Instruction Manual.
3.4
IEEE-488 bus control
3.4.1 Closing and opening channels
Closing channels
Use the following SCPI command to close channels:
:CLOS <list>
For example, the following command will close channels 2
and 6 of a Model 7038 installed in slot 1:
:CLOS (@ 1!2, 1!6)
Again, be sure not to close more than one channel per multi-
plexer to maintain 75
Ω
characteristic impedance.
Opening individual channels
Use the following command to open selected channels:
:OPEN <list>
For example, the command below will open previously
closed channels 2 and 6:
:OPEN (@ 1!2, 1!6)
Using :OPEN ALL
Sending :OPEN ALL will open all channels except channels
1, 5, and 9. Since those three channels are normally closed,
they will close when the :OPEN ALL command is sent.
3.4.2 Scanning channels
There are a number of commands associated with scanning.
However, you can perform a simple scan using only the fol-
lowing four commands:
*RST
:TRIG:SEQ:COUN:AUT ON
:ROUT:SCAN <list>
:INIT
The *RST command selects the default scan configuration,
while the second command automatically sets the channel
count to the number of channels in the scan list. The
:ROUT:SCAN command programs the scan list, and the
:INIT command takes the mainframe out of the idle state.
For example, send the following commands to scan through
all 12 channels of a Model 7038 installed in slot 1:
*RST
:TRIG:SEQ:COUN:AUT ON
:ROUT:SCAN (@ 1!1:1!12)
:INIT
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