Keithley 2790, Reference Manual

Page: 208 / 568

Model 2790 SourceMeter
®
Switch System Reference Manual 7-3
ber of the switching module. This is accomplished by using a 3-digit channel number for
the mainframe. The first digit (1 or 2) indicates the slot number, and the next two digits
indicate the channel number of the switching module. Examples:
Channel 101 Slot 1, channel 1
Channel 112 Slot 1, channel 12
Channel 220 Slot 2, channel 20
Sequential and non-sequential scans
Only a sequential scan can be configured from the front panel. For a sequential scan, the
scan proceeds from the lowest numbered channel to the highest. For example, assume
channels 101, 102, 105, 108, and 109 are selected for a scan. The scan will run in this
order: 101 > 102 > 105 > 108 > 109.
For remote programming, a non-sequential scan can be configured. Channels are scanned
in the order that they are listed in the scan list. This allows backward scanning. For exam-
ple, assume the following scan list:
(@101, 102, 104, 105, 103, 109)
The above scan will run in this order: 101 > 102 > 104 > 105 > 103 >109. Notice that after
channel 105 is scanned, the unit backs up to scan channel 103. It then proceeds forward to
scan channel 109. Any scan that performs backward scanning is considered a non-
sequential scan. For more information on non-sequential scanning, see the reference infor-
mation for the ROUT:SCAN command that follows
Table 7-1 .
klqb
Non-sequential scanning is only intended to be performed using remote pro-
gramming. Unexpected results may occur if a non-sequential scan is run from
the front panel.
Channel assignments
A switching module has a certain number of channels. For example, the Model 7702
switching module has 42 channels (1 through 42). When you encounter a 1 or 2-digit
channel number in this manual, the switching module channel is the point of discussion.
A switching module can be installed in one of two slots of the mainframe. Therefore, to
close/open or scan a channel, it is necessary to specify the slot location and channel num-
ber of the switching module. This is accomplished by using a 3-digit channel number for
the mainframe. The first digit (1 or 2) indicates the slot number and the next two digits
indicate the channel number of the switching module. Examples:
Channel 101 Slot 1, channel 1
Channel 112 Slot 1, channel 12
Channel 220 Slot 2, channel 20