Keithley 2700, User Manual, Page: 57 / 500

2-2 Close/Open Switching Module Channels Model 2700 Multimeter/Switch System User’s Manual
Close/open overview
NOTE
This section covers basic close/open operations for switching module channels.
It also covers the operating characteristics that are unique to the Model 7700
switching module.
There are two modes of close/open operation:
• System channel operation — This is the mode of operation that should be used
exclusively by most (if not all) users. When you close an input channel (or channel-
pair), other channels on the switching module close automatically to internally
connect it the DMM of the Model 2700.
• Multiple channel operation — This mode of operation provides additional flexibility by
providing individual control of each switching module channel. However, careless
operation could create a safety hazard and/or damage the switching module and other
equipment. Multiple channel operation should only be used by experienced test
engineers.
CAUTION To prevent damage to a switching module, do not exceed the maximum
signal level input for that module. Most switching modules are rated
for 303V. The following command queries maximum module voltage:
SYSTem:CARDx:VMAX? ‘Request maximum allowable voltage for
‘CARDx (where x is the slot number for
‘the module).
For system channel operation, the instrument will display the
“OVERFLOW” message when the maximum allowable voltage for the
module is being exceeded.
However, for multiple channel operation, the “OVERFLOW” message
will not occur until the maximum voltage of the mainframe (not
module) is exceeded. Therefore, the “OVERFLOW” message would
occur only if 1010V is exceeded.
WARNING Careless multiple channel operation could create an electric shock
hazard that could result in severe injury or death. Improper operation
can also cause damage to the switching modules and external circuitry.
Multiple channel operation should be restricted to experienced test
engineers who recognize the dangers associated with multiple channel
closures.
NOTE
The Model 2700 can scan switching module channels. Each channel in the scan
can have its own unique setup configuration. Scanning is covered in
Section 7 .
NOTE
When a setup is saved as a user setup (SAV0, SAV1, SAV2, or SAV3), closed
channels are also saved. When the setup is restored, those channels (and only
those channels) will be closed (see
“Defaults and user setups,” page 1-20 ).