Keithley 2450 Reference Manual page 41

Section 2: General operation
Instrument communication activity indicator
Located directly to the right of the communications settings status indicator, these up and down
arrows flash when the instrument is actively communicating with a remote interface.
If a service request has been generated, SRQ is displayed to the right of the up and down arrows. You
can program the instrument to generate a service request (SRQ) when one or more errors or
conditions occur. When this indicator is on, a service request has been generated. This indicator
stays on until the serial poll byte is read or all the conditions that caused SRQ are cleared.
Active buffer indicator
Located to the right of the instrument active state indicator arrows, this indicator shows the name of
the active reading buffer. Select the indicator to open a menu of available buffers. Select a buffer
name in the list to make it the active reading buffer. The name of the new active reading buffer is
updated in the indicator bar. The green bar next to the buffer name indicates how full the buffer is.
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Model 2450 Interactive SourceMeter® Instrument Reference Manual
Figure 10: Instrument communication activity indicator
Figure 11: Model 2450 active buffer indicator expanded
2450-901-01 Rev. B/September 2013