User manual

Series 3700 System Switch/Multimeter Reference Manual Section 13: Instrument Control Library (ICL)
3700S-901-01 Rev. C / July 2008 13-231
scan.add()
Remarks
Use this function to specify additional channels and channel patterns to scan. These
items are appended to the end of the existing scan list that was specified by the
scan.create() (on page 13-234) command. The items in ch_list are
appended and scanned in the order specified in the parameter list. Specifying a
channel list results in multiple steps being added to the scan.
If the optional dmm_config parameter is not specified, the configuration associated
with that channel or channel pattern is used (see dmm.setconfig() (on page 13-
168) and dmm.getconfig() (on page 13-139)). If a dmm_config is specified,
then that configuration is used for each channel or channel pattern specified in a
temporary override mode. It does not modify the assigned configuration of a channel
or channel list.
The scan list of channels or channel patterns are not updated if any error occurs
during processing of the command. However, steps already added to the scan list with
prior commands remain unchanged with an error detection.
For digital I/O or totalizer channels, the created scan step instructs the scan to read
the given channel and deposit the read value into the specified reading buffer. If no
reading buffer is specified, the channel is read, but the value is lost.
The width parameter is only valid for channels of type digital I/O. Only a width of 1,
2, 3, or 4 is supported. If specified, the scan reads up to four consecutive channels
simultaneously during the scan and deposit the resulting value into the specified
reading buffer.
DAC channels are not supported.
NOTE Because reading buffer time stamps are generated differently for different
channel types, there can be some variance when comparing measurement
time stamps to channel read time stamps.
Also see
scan.create() (on page 13-234)
Example
To clear the old scan list and to create a new scan list with Channels 1 to 10 on Slot 3
with myDCV, a user DC volts configuration, on all 10 channels and then use
my2wire, a user 2-wire ohms configuration, on all 10 channels:
scan.create('3001:3010', 'myDCV')
scan.add('3001:3010', 'my2wire')
To clear the old scan list and to create a new scan list with Channels 1 to 10 on Slot 3
with myDCV, a user DC volts configuration, on all 10 channels and then my2wire, a
user 2-wire ohms configuration, on each step:
scan.create('')
for chan = 3001, 3010 do
scan.create('' .. chan, 'myDCV')
scan.add('' .. chan, 'my2wire')
end
NOTE With respect to the scan.add function in the above example, the first
parameter ('' .. chan, converts the chan number to a string.