User manual

Series 3700 System Switch/Multimeter Reference Manual Section 8: Scanning
3700S-901-01 Rev. C / July 2008 8-3
Event blenders
Advanced event handling requires a way to wait for one of several events (or all
of several events). An event blender provides for this combining or blending of
events. An event blender can combine up to four events in either an "or" mode
or an "and" mode. When in "or" mode, any one of the input events will cause an
output event to be generated. When in "and" mode, all the input events must
occur before an output event is generated.
When operating in "and" mode, if an event is detected more than once before all
events necessary for the generation of an output event, an action overrun will be
generated. When operating in "or" mode, an action overrun will be generated
when two or more source events are detected simultaneously.
Event blenders each have an associated event detector that can be accessed
through script control. Event blenders can only be accessed over the bus (no
front panel control is available). The following ICL commands provide additional
information on available blenders:
trigger.blender[N].clear() (on page 13-287)
trigger.blender[N].orenable (on page 13-287)
trigger.blender[N].overrun (on page 13-288)
trigger.blender[N].stimulus[M] (on page 13-288)
trigger.blender[N].wait() (on page 13-289)
Foreground and background scan execution
You can execute a scan in the foreground or background. Background execution
allows you to query settings or access reading buffer data. If a scan is running in
the foreground, it will need to finish or be aborted before you can query any
settings or access reading buffers.
When a scan is running in the background, you can send ICL commands to be
processed. The commands that you can use include most of the command
messages that you use to query for settings, for example:
print(dmm.func)
print(dmm.scan.state())
printbuffer(1, 5, rb)
print(scan.state())
Most of the commands to change how the instrument is configured will log the
following error message to the error queue, if not allowed:
5522, Scan Running, Must Abort Scan