Series 3700 System Switch/Multimeter Reference Manual
Section 7
:
Scanning
Document Number: 3700S-901-01 Rev. A / August 2007
7-3
slot.PSEUDO_3730
or
3730
Model 3740 32 channel isolated switch card:
slot.PSEUDO_3740
or
3740
For example, to set the attribute to "install" the Model 3720 pseudocard in Slot #6:
slot[6].pseudocard = slot.PSEUDO_3720
When queried, the return value will have "Pseudo" before the card description. For example:
print(slot[3].idn)
3720,Pseudo Dual 1x30 Multiplexer,00.00a
NOTE
The revision level of a pseudocard will always be returned as 00.00a.
Query the
slot[X] attributes
(on page 9-176) to determine the capabilities of the installed
switching modules. For example, send the following query to determine if Slot 1 supports
common-side 4-wire
channels:
CommonSideOhms1 = slot[1].commonsideohms
2-wire scan process
For functions that use 2-wire measurements, the basic scan process is to (1) open any closed
channel, (2) close a channel, and then (3) perform the measurement. This 3-step process is
repeated for each channel in the scan. The channels associated with the last scan step will
remain closed when the scan completes.
NOTE
Scanning is given priority when actively scanning. Therefore, the front panel display
may not reflect the present channel state or measurement value.
4-wire scan process
For the functions that use 4-
wire measurements (Ω4 and 4-wire RTD TEMP), the scan process
uses paired channels. The scan process is to (1) open any closed channel, (2) close the paired
channels, and then (3) perform the 4-wire measurement. Again, the channels associated with
the last scan step will remain closed when the scan completes.
